This book offers the latest scientific research on applied microbiology presented at the IV International Conference on Environmental, Industrial and Applied Microbiology (BioMicroWorld2011) held in Spain in 2011. A wide-ranging set of topics including agriculture, environmental, food, industrial and medical microbiology makes this book interesting not only for microbiologists, but also for anyone who likes to keep up with cutting-edge research in microbiology and microbial biotechnology.
Readers will find a major collection of knowledge, approaches, methods and discussions on the latest advances and challenges in applied microbiology in a compilation of 136 chapters written by active researchers in the field from around the world.
The topics covered in this single volume include biodegradation of pollutants, water, soil and plant microorganisms, biosurfactants, antimicrobial natural products, antimicrobial susceptibility, antimicrobial resistance, human pathogens, food microorganisms, fermentation, biotechnologically relevant enzymes and proteins, microbial physiology, metabolism and gene expression mainly, although many other subjects are also discussed.
Sample Chapter(s)
A microcosm study on the die-off response of the indicator bacteria, Enterococcus faecium and Enterococcus faecalis (267 KB)
https://doi.org/10.1142/9789814405041_fmatter
The following sections are included:
https://doi.org/10.1142/9789814405041_0001
In this study, a microcosm experiment is set up to investigate the die-off response of Enterococci to the range of environmental conditions in Hong Kong. Four local strains of Enterococcus faecium and Enterococcus faecalis were selected from wastewater samples from three representative sewage treatment plants in Hong Kong. Their die-off rates under different combinations of light intensity, salinity, nutrient and temperature were determined from the rate of change of Enterococci concentration. The relative influence and interaction of the four factors were studied with 3D response surface analysis. It is observed that 1) Light intensity is the primary factor governing the elimination of Enterococci; 2) Enterococci has high tolerant to salinity at low light intensity, but its tolerance reduces significantly with the increase of light intensity; 3) Nutrient does not enhance the survival of Enterococci cells under light condition; 4) The die-off response of Enterococci to temperature follows a sag curve. Based on the results, a die-off equation is constructed for Enterococci, which will be useful for future water quality management.
https://doi.org/10.1142/9789814405041_0002
We study alternative protection on the occurrence of mass dieback in oak forests seedlings in Central Serbia (caused by Microsphaera alphitoides Griff. et Maubl.) with various dosages of AQ-10 biofungicide, which is a pelleted formulation of conidia of Ampelomyces quisqualis Ces. ex Schlechtend. Simultaneous testing was conducted on the efficacy of a chemical sulphur-based preparation. The results of the research have demonstrated that AQ-10 biofungicide can be used as a part of integrated disease management programmes as an alternative. The best results in suppression of oak powdery mildew were attained through use of sulphur SC in the concentration of 0.5%, while very satisfactory results were obtained by use of AQ-10 biofungicide in the highest dosage of application (70 g/ha). The number of treatments was proven to have no significant impact on increased efficacy of the bio-preparation, or in other words, it showed that besides the application dosage, the high efficacy of the biopreparation depends primarily on proper timing of the application.
https://doi.org/10.1142/9789814405041_0003
The individual-based model INDISIM-SOM, made up by biotic and abiotic elements, encompasses a wide range of physical, chemical, and microbiological processes that control the short-term dynamics of soil C and N, namely, decomposition, mineralization or immobilization of C and N, and humification. In order to model the addition of slurry and mineral N into soils, a new version of INDISIM-SOM, called INDISIM-SOMFERTL, whcih allows study of the variables linked to turnover of soil C and N, has been developed. The parameterization and initialization of the new simulator has been modified with respect to INDISIM-SOM, together with some of the sub-models involved, mainly those linked to ammonia adsorption and desorption and the use of labile N or labile C as energetic sources for microbial maintenance. New values for some parameters were obtained in order to fit the simulations to a set of experimental data.
https://doi.org/10.1142/9789814405041_0004
Batch studies were carried out in the laboratory to evaluate the ability of mixed microbial populations to degrade various fats, oils and greases (butter and Greek extra virgin olive oil) in 1% concentration. The inoculum was added to 250 ml Erlenmeyer flasks containing 100 ml of sterile culture medium to which the carbon source was added. Two culture media were investigated, a minimal medium and an enriched nutrient medium. The flasks were incubated aerobically at 30° C and agitated at 150 rpm for 7 to 14 days. The microbial populations investigated comprised bacteria of the genera Bacillus and Pseudomonas and a fungus. Optimal results were obtained for a product containing a mixture of Bacillus spp. and a Pseudomonas sp.
https://doi.org/10.1142/9789814405041_0005
The golden chanterelle mushroom (Cantharellus cibarius), also known as girolle, is an edible mushroom, renowned as a delicacy especially prized for its unique flavor. As an ectomycorrhizal fungus, C. cibarius grows in symbiosis with the root tips of forest trees, giving rise to an inextricable relationship between tree vitality and mushroom thriving. In this research, the activity of key intracellular anti-oxidative stress enzymes, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX), was investigated and characterized in C. cibarius mushroom. A C. cibarius homogenate was centrifuged at 3,000 g for 10 min, then at 35,000 g for 30 min; the supernatant (“crude extract”) was used for our studies. Data showed that up to 18 units SOD, 10 units CAT, and 0.11 units POX, were detectable per mg protein in the extract. Non-denaturing polyacrylamide gel electrophoresis of the extract, followed by activity staining, revealed one SOD band (estimated M.W. 30.2 kD), at least two CAT bands (estimated M.W. 280 and 350 kD), and at least one POX band (estimated M.W. 45 kD).
https://doi.org/10.1142/9789814405041_0006
The paper deals with decontamination of sediments polluted by persistent organic pollutants in the influent stream of Cerny prikop in Ostrava, the Czech Republic. Flotation is used as the first stage treatment method when the individual contaminants accumulate in the flotation concentrate. Consequently, bacterial leaching applying the bacteria of genus Rhodococcus is used as the second treatment method. The results imply that the combination of both methods is very effective and leads to a removal of up to 70% of PAHs, PCBs and C10 – C40.
https://doi.org/10.1142/9789814405041_0007
The aim of this study was to evaluate the bacterial contamination of the Domat Al-Jandal lake, Al-Jouf Province, Saudi Arabia and to estimate the antibiotic sensitivity against the isolated pathogenic bacteria. Samples included water from the agriculture watershed source pipes, western, eastern, north and south basins of the lake. The analytical results obtained indicated that there are considerable variations among the examined samples with respect to their microbial composition. Microbiological analyses indicate that the only issue of true concern is the total coliform, which was too numerous to count and, therefore, warrants more attention. Thermotolerant coliforms, E. coli, Enterococcus spp., Salmonella sp., Staphylococcus spp. and Pseudomonas aeruginosa were detected in samples. In general, the count of the different pathogens in lake is relatively higher than that in agriculture watershed source pipes. Antibiotics susceptibility testing was selected, pathogenic bacterial isolates revealed resistance against most applied antibiotics. The levels of resistance of bacterial isolates to various antibiotics differed considerably. The occurrence of total and fecal coliform bacteria in counts suggests warns of the potential presence of disease-causing organisms in Domat Al-Jandal lake.
https://doi.org/10.1142/9789814405041_0008
Biodegradation experiment was carried out to evaluate the effects supplementation of microbial consortium and bulking agents in biodegradation of crude oil in soil. The soil with indigenous microbes was spiked with crude oil at 50,000 ppm and a cocktail of microbial consortium at ratio 1:1:1:1 (v/w) which consist of Pseudomonas sp. UKMP 14-T, Acinetobactersp. UKMP 12-T and two fungi isolates Trichodermasp. (TriUKMP-1M and TriUKMP-2M). Bulking agents (sugarcane baggasse (SB) and empty fruit bunch (EFB) from oil palm) at 15% and 20% (w/w), respectively were added and mixed thoroughly. The pH and moisture content of the soil was maintained at 6.5 and 40% VWC, respectively. The degradation of crude oil from the soil was analyzed using gas chromatography-flame ionization detector (GC-FID) and the growth of bacteria was estimated using spread plate method. The result showed that biodegradation of crude oil by microbial consortium with addition of SB produced 100% Total Petroleum Hydrocarbon (TPH) degradation as compared to 91% with EFB after 30 days incubation. The control plot which contains only indigenous microbes showed 62% degradation at the same period of incubation. The results indicate that the types of the bulking agent may influence the intake of the nutrient source by microbial consortia hence influenced the percentage of the TPH degradation.
https://doi.org/10.1142/9789814405041_0009
In this study one hundred and forty seven strains of actinomycetes from urban and industrial wastewater treatment plants with foaming problems were isolated and identified by using phenotypic and genotypic procedures. The chemotaxonomic tests and the analysis of the sequences of gene 16S rRNA showed that the isolated belonged to the genera Corynebacterium, Dietzia, Gordonia, Mycobacterium, Rhodococcus, Tsukamurella and Williamsia. Biodegradation assays were carried out in three different mineral media supplemented with phenol and naphthalene as sole carbone source. The catalysis of the aromatic ring was confirmed by PCR of gene catA, which encodes cathecol 1,2-dioxygenase. The amplified catA genes were sequenced. It is shown with this study that residual wastewater treatement plants can be a good source of microorganisms with many potential applications, such as bioremediation and biodegradation.
https://doi.org/10.1142/9789814405041_0010
Azo dyes are extensively used for coloring textiles, paper, food, leather, drink, pharmaceutical products, cosmetics and inks. The textile industry consumes the largest amount of azo dyes, and it is estimated that approximately 10 – 15% of dyes used for coloring textiles might be lost in waste streams. Almost all azo dyes are synthetic and resist biodegradation, however, they can be readly reduced by a number of chemical and biological reducing systems. Biological treatment is advantageous over physical and chemical method as result of its low cost and little disturbance to the environment. This research focuses on the utilization of Aspergillus oryzae, to remove some kinds of azo dyes from aqueous solutions. The fungi, physically induced in its paramorphogenic form (called, “pellets”),were used in the dyes biosorption studies with both non autoclave and autoclaved hyphas, at differents pH values. Thus the goals are the removal of dyes by biosorption and the decrease of its toxicity.
https://doi.org/10.1142/9789814405041_0011
This work aimed to evaluate the potential of biosurfactant produced by Rhdotorula glutinis using industrial wastes as substrates. The production was made in flasks (250 ml) containing 100 ml of means of production according to an experimental kind CCRD, varying the concentration of cassava wastewater, waste corn steep liquor and ice cream. Later, he was selected the best condition to make the factorial design optimization. Production was transferred to the reactor with a capacity of dual-shirt 2L under the same conditions. Were inoculated 5% of the pre-inoculum (Sabouraud Dextrose Broth), fermentation took place for 72 hours, 150 rpm at 28°C. Were determined the surface tension and interfacial fluid cell-free metabolic, obtaining surface tension de28, 2 mN/m interfacial 5.1 mN/m. Has been demonstrated effective stability of biosurfactant at different pH’s, temperatures and salinity determined by tensão. Subsequently was determined emulsification index of stability. The results obtained for biosurfactant production by R. glutinis using industrial waste is an alternative that comes to the economy and contribute to the preservation of the environment
https://doi.org/10.1142/9789814405041_0012
Genomic sequencing and thermodynamic predictions suggest that methanogenic Archaebacteria may contribute to heavy metal reduction at the community level. Microorganisms from six Yellowstone National Park hot springs were tested for Cr(VI) reduction under methanogenic conditions. Biological reduction was observed in 5 of the 6 samples, with Nymph Creek and Narrow Gauge being the most active. The addition of 20 mM BESA resulted in marked decreases in Cr(VI) reduction (15-46%) for each site, indicating that methanogenic bacteria may contribute to Cr(VI) reduction in these communities.
https://doi.org/10.1142/9789814405041_0013
This paper presents the results concerning total number of cells capable of growth and multiplication (direct viable count) in marine microcosms supplemented with gasoline and gasoline-enriched marine populations. The direct viable count is further discussed in correlation with the BOD5 of these samples in the attempt to take into account the intensity of biological oxygen consumption together with the number of active growing microorganisms. The linear correlation between the number of cells capable of growth and multiplication (direct viable count) and BOD5 in the five microcosms is good (r= 0.96). Up to our best knowledge this is the first attempt to simultaneously measure these two parameters in marine microcosms polluted with hydrocarbons (gasoline).
https://doi.org/10.1142/9789814405041_0014
Microbial communities in rice plantations display distinct patterns in frequency of abundance and in their relationships with physical and chemical variables. The present study proposes to estimate the diversity of cultivatable bacteria spore-producers present in water samples collected in the rice growing regions of the Brazilian South, and relate them to the physical and chemical characteristics of the water. The samples were obtained in the irrigation and drainage channels of irrigated rice plantation during the 2007/2008 crop year. The bacteria were characterized morphocytochemically and identified by sequencing after extraction of the total DNA and amplification of the PCR of the 16S rRNA gene. The results revealed 152 isolated bacteria including 13 cataloged taxa. The Analysis of Canonical Correspondence demonstrated that the first two axes explained 43.2% of the total variation in the composition of the taxa. Considering the frequencies in the species, the drainage and irrigation channels in Cachoeirinha and the irrigation channel in Camaquã showed similarity of bacterial composition of more than 80%, while the drainage channel in Camaquã was the most dissimilar.
https://doi.org/10.1142/9789814405041_0015
A preliminar typing scheme has been developed for the characterization of the bacterial population present in plant and fruit tissue of summer squash. The objective of this work is to stablish a systematic method to differenciate among saprophitic or pathogen bacterial strains isolated from plant or fruit tissues in order to know about their role in non-chilling postharvest lesions, origin and possible routes of contamination.
Tissue fragments of summer squash were cultivated directly or previously macerated on buffered peptone water and then streaked on nutrient agar plates. A total of 27 isolates were investigated by means of morphology of colonies and biochemical tests showing at least 13 biotypes. Colony appearance, cellular morphology, Gram staining and a total of eleven biochemical tests were used to differenciate amongst the isolates, offering a good discrimination ability. Three isolates were positive for tobacco sensitivity test in Nicotiana xanthi leaves.
More research is needed to identify at the specie, subespecie and patovar level using molecular tools in order to determine the possible presence of pathogen bacteria.
https://doi.org/10.1142/9789814405041_0016
The diuron is an herbicide used on autumn-winter crops, due to its ability to block the chloroplast electron chain at level of photosystem II. Furthermore, diuron can also exert toxic effects on heterotrophic beings, blocking the respiratory chain and ROS generating. Despite the progressive suppression of diuron application by Directive 200/60/CE, groundwater contamination will still persist. Therefore the main purpose of this work was to evaluate the effect of this phenylurea on S. cerevisiae at proliferative phase. The results show a significant decrease of GSH/GSSG ratio, in cells exposed to 50 μM diuron. Although GR activity does not changes significantly in any assay of this study, it was observed a significantly decrease of G6PD and GPx enzyme activities, in cells grown in 50 and 75 μM diuron. The decline of NADPH availability probably blocks the glutathione cycle, generating oxidative stress. In addition, the CAT T activity presents also a significant increase in cells grown in 50 μM diuron, as well as an increase of cytoplasm ROS, MDA level and CAT A activity in cultures with 50 and 75 μM diuron, that suggests a key role of peroxisomal lipid oxidation in diuron response which cause cell death by an active process.
https://doi.org/10.1142/9789814405041_0017
Knowledge on the evolution of symbiotic bacteria elicited by their co-migration with host plants into the novel soil/climatic environments should be used as a conduit for constructing the beneficial plant-microbial systems applied in sustainable agriculture. Co-migration of leguminous plants and nodule bacteria (rhizobia) from the centers of origins into cropping areas often results in generating the Novel Symbionts (NS) via the “symbiotic” gene transfer from initial symbionts to the local soil or plant-associated bacteria. NS usually combine the low/zero activity of N2 fixation with the high competitiveness for soil and nodular niches blocking the inoculation of leguminous crops by commercial strains. Mathematical simulation of legume-rhizobia interactions suggests that this effect may be due to retarding the evolution of NS towards the elevated N2-fixing activity. Construction of co-adapted “gene-for-gene” systems is a promising approach to ensure the competitive advantage of effective (commercial) rhizobia strains over the ineffective (NS, local) strains. This advantage may be ensured also by engineering the genes responsible for soil adaptations and nodulation competitiveness into the rhizobia genotypes capable of active N2 fixation.
https://doi.org/10.1142/9789814405041_0018
Rice is one of the most widely consumed foodstuffs all over the world and 63% of all the rice produced in Brazil is grown in the State of Rio Grande do Sul. The purpose of this study was to evaluate the influence of irrigated rice on the microbiotic composition of the soil, in view of the fact that this plays an important part in the maintenance of the land and thus has an effect on the production of the rice plantations. Soil bacteria were isolated in four cultivation systems and three species were identified by the morfocytochemical method: Bacillus thuringiensis, B. cereus and Lysinibacillus sphaericus. The results obtained demonstrate the predominance of Gram-positive spore-forming bacteria in the four cultivation systems. The frequencies of the species differed according to the phenological phases of the plants. The two chemical/physical parameters related to the bacterial groups were: H+Al, which influenced positively the spore-forming bacteria and the Mg which positively influenced the B.thuringiensis species. This data shows that that the rice plantation ecosystems are complex and that other abiotic factors also can be evaluated in studies of bacterial species in agroecosystems.
https://doi.org/10.1142/9789814405041_0019
In this study a total of 16 Bacillus strains isolated from the some soil examples in Turkey. Also fungi were isolated from diseased sugar beets by using Rose Bengal Chloramphenicol (RBC) Agar and incubated at 25°C for 5-7 days. Identification of grown isolated bacteria colonies was based on morphologic, biochemical and culturing characteristics. However, macroscopic and microscopic properties of the fungi isolates are examined and they were identified microscopically to genus level with traditional methods using diagnostic literatures. Antifungal activity of isolated bacteria strains were determined against Fusarium oxysporum, Fusarium solani, Fusarium culmorum, Fusarium moniliforme standard strains and our 2 Fusarium sp. isolates. Isolated 16 bacteria strains were Gram positive rods and were identified as Bacillus sp. and our 2 fungal isolates were identified as Fusarium sp. As a result of antimicrobial activity studies, 6 Bacillus spp. isolates had antibacterial activity against at least two or more Fusarium strains. The inhibition zones ranged between 1.5±0.000 −7.6±0.000 cm.
https://doi.org/10.1142/9789814405041_0020
Soil disinfestation (SD) with methyl bromide (MB) was a standard practice until its banning in 2005 to control soil-borne diseases and to prevent soil fatigue in pepper crops in Southeast Spain. This effect occurs when SD is not carried out between two consecutive crops in the same soil and it seems to be associated with a build-up of soil fungi at the end of the crop cycle. Alternatives to MB as biofumigation (B) and biosolarization (biofumigation with solarization, BS) were deeply studied since then. The effects of and the repetition of BS in the same plots with a gradual decrease in the amount of applied manure (a mixture of fresh sheep and chicken manures) were evaluated at two different locations during one and three years respectively. Soil fungal density was estimated in each plot before and after treatments where Aspergillus spp., Fusarium spp., Penicillium spp. and Rhizopus spp. were systematically present and clearly reduced after SD. B and BS reduced fungal density to the same extent as MB though no treatment eliminated them. The progressive reduction of manure applied did not lead to a lower efficacy than MB.
https://doi.org/10.1142/9789814405041_0021
This research investigated the effect of initial pH on hydrogen production by elephant dung from enzymatic hydrolysate of acid-pretreated sugarcane bagasse (SCB). The acid-pretreated sugarcane bagasse was hydrolyzed with 20 U/g commercial cellulase derived from Trichoderma reesei. The resulting hydrolysate had the glucose concentration of 3.19 g/L which was subsequently used as the substrate to produce hydrogen by elephant dung in batch fermentation at various initial pH of 3-8 with an increment of 0.5. Elephant dung was heat-treated in boiling water for 2 h before used as the seed inoculums in order to inhibit methanogenic activity. The experiments were conducted in 10 mL serum bottles with a working volume of 7 mL. Culture of the hydrolysate at the initial pH 7 provided a maximum hydrogen production (HP) and hydrogen yield (HY) of 410.97 mL and 0.93 mol H2/mol total sugars consumed, respectively. Main soluble products were acetate and butyrate suggesting that the hydrogen fermentation from the enzymatic hydrolysate of acid-pretreated SCB is the acetate-butyrate type.
https://doi.org/10.1142/9789814405041_0022
Erwinia amylovora is a pathogenic bacterium affecting economically important rosaceous plants worldwide. It causes fire blight, one of the most difficult-to-control diseases of pome fruit trees, which has been related to the ability of the pathogen to respond to changes in the environment. Bacteria can respond to environmental stresses by activating the expression of rpoS gene, encoding the alternative sigma factor RpoS, involved in cell protection against environmental challenges, such as nutrient limitation. We aimed to study the possible involvement of the sigma factor RpoS on the short-term survival of the fire blight pathogen under natural conditions of nutrient scarcity in water. Then, a mutant in the rpoS gene was obtained from E. amylovora and the survival of this mutant and its wild type parent strain was monitored along one week in water microcosms. Initial results have shown that the rpoS mutant exhibited a reduction in culturability and viability over time not observed in the wild type parent strain, suggesting that rpoS gene may help E. amylovora to survive under natural nutrient limitation conditions.
https://doi.org/10.1142/9789814405041_0023
Polychaete marine community distribution (specimens and species) along the coast of the Villanova (Brindisi, Italy) has been investigated. Two sites were sampled: the Port of Villanova and the sea at the outflow of a streamchannel, 1.5 km distant from the Port. The benthonic substratum was sampled for Polychaeta and other biota during March, May and July 2010. The collected Polychaeta were counted and classified. At the Villanova Port were recovered 21 species and 127 specimens of Syllidae and Orbiniidae, with a maximum of 66 specimens in July. At the second site we found only 15 specimens of Sabellidae during May 2010. Water quality and polychaete population have been treated by statistical methods to find the relationship between anthropogenic activities, climatic variables and polychaete population distribution. Finally, actions necessary to re-address the marine ecosystem at Villanova to the uncontaminated status, have been focalized by means of STELLA model.
https://doi.org/10.1142/9789814405041_0024
Nu Film 17 and Nu Film P are emulsifiable concentrate formulations of a specific ß-pinene polymer, designed for use as a spray tank additive, to be applied in combination with fungicide pest control programs. They are filmforming polymers, which encapsulate the pesticides and provide protection from various weathering factors, including rainfall and wind erosion. It has been found that the use of polymers reduces the quantity of pesticides needed in spray applications. It improves initial depositing of the pesticide so that lower rates of pesticide can be used. It increases the normal life of most pesticides by 50-100%. The experiments were carried out in the nursery on the seddlins Quercus robur L. The trial were set according to the instruction of methods PP 1/152 (2) and PP 1/69 (2). Phytotoxicity was estimated by PP 1/135 (2), the intensity of infection according to Towsend-Hauberger, the efficiency by Abbott, the analysis of variance with Duncan test and PP/181 (2).
https://doi.org/10.1142/9789814405041_0025
The isoproturon is a systemic herbicide applied in pre- and post-emergence control of annual grasses and broadleaved weeds in winter crops that block photosynthesis, being listed by European Union as special substance that threaten the earth surface. Probably, can generate reactive oxygen species blocking the respiratory chain and cause oxidative stress and cell death. So, the main purpose of this study was to evaluate the effect of isoproturon on the antioxidant capacity of the wild-type Saccharomyces cerevisiae UE-ME3 and IGC-4072 strains. The UE-ME3 strain showed an adaptive response to this phenylurea, showing a growth similar to that control cells, an increase of non-protein thiols content, cell viability and glutathione antioxidant capacity, response that depend on glutathione reductase and glucose-6-phosphate dehydrogenase activities. However, the IGC-4072 strain in the presence of isoproturon showed cell death, exhibiting a poorly growth, dry weight and cell viability decrease, as well as a significant increase of free radicals scavenger (DPPH) and glutathione peroxidase activity.
https://doi.org/10.1142/9789814405041_0026
Sixteen strains of filamentous fungi were isolated from soil samples collected from Livingston Island, Antarctica. The isolates’ taxonomic identifications were performed based on morpho-dimensional parameters following the most suitable identification keys for the different genera. The affiliation of the investigated strains was established to the particular genera. The obtained fungal isolates were members mostly to the genera Penicillium, Aspergillus and Cladosporium. All strains were studied for their ability to adapt to aromatics containing media. Most of the investigated strains demonstrated good tolerance to the presence of 0.5 g/l phenol in the culture medium. More than that the investigations showed that strains were able to grow in a culture medium containing phenol in concentrations varying form 0.1 to 0.7 g/l as a single source of carbon and energy. The experiments carried out with hydroxyl-, methyl- and nitro- phenol derivatives revealed the capability of some of the strains to grow and utilize various of these aromatic compounds. The strains Aspergillus sp. AL1, Aspergillus sp. AL8, Aspergillus AL9, Aspergillus sp. AL15, Penicillium sp. AL5 and Penicillium AL11 were able to grow and utilize as a sole carbon sources 0.3 g/l of each examined aromatic compound. There were not found strains able to utilize any of the tested nitrophenols. The representatives of Cladosporium as well as strain Lecanicillium sp. AL12 did not show any capability to degrade phenol derivatives.
https://doi.org/10.1142/9789814405041_0027
The environmental levels of titanium dioxide nanoparticles (TiO2-NP), a new material described as ROS generator, has increased in several regions of the earth due its massive industrial use. Thus, the main purpose of this work was to determine the influence of temperature on response to TiO2-NP by S. cerevisiae UE-ME3. The results show that cells grown at 28 °C show dry weight, protein and glutathione contents higher than cells grown at 40 °C. In addition GSH content increased in cells exposed to nanoparticles at 28 °C. The GSH/GSSG ratio is greater in cells grown at 40°C, probably due a sharp decrease of GSSG and GPx activity, more evident in TiO2-NP exposed cells. Furthermore, an increase of MDA level detected in S. cerevisiae growing in presence of 1μg/mL TiO2-NP at 28 °C, related with an increase of LOX and GPx activities as well as ROS contents, points TiO2-NP as inducer of oxidative stress and cell death.
https://doi.org/10.1142/9789814405041_0028
Bioleaching is the dissolution of metal sulfides like pyrite by bacterial oxidation processes. Beside desired heap or tank leaching for winning metals such as copper or gold, unwanted bioleaching causes acid mine drainage (AMD)/acid rock drainage (ARD) e.g. in during coal mining processes. Bioleaching can cause acidification of surface- and groundwater concomitant with pollution by high amounts of heavy metals. The addition of a surfactant to active leaching cultures decreases bacterial cell numbers and leaching. To investigate the inhibition effect of the surfactant in situ, a percolator system was used. Percolators were filled with pyrite containing material from a brown coal area where unwanted bacterial leaching occurs. The surfactant was added after bacterial leaching was established. The addition of the surfactant inhibited leaching within one week till the end of the experiment after 13 weeks. Based on these findings, applications for the inhibition of bacterial leaching in brown coal mining areas can be established.
https://doi.org/10.1142/9789814405041_0029
Parasporal protein inclusions from Bacillus thuringiensis are widely studied as a biological agent in order to control pest. However, recently it has been attracted attention for other biological activities. One of the most remarkable is anti-cancer activity. The Parasporins are a new category of Cry proteins which are non-hemolytic neither insecticide but they preferentially kill cancer cells. The aim of this study was the detection of Parasporins in 100 Bacillus thuringiensis strains isolated from Mexican soil-samples and their evaluation of cytopathic effect (CPE) against leukemia cells MOLT-4. In order to identify putative Parasporin genes, we designed six pairs of primers to amplify the eighteen Parasporin genes in a multiplex system. Our screening revealed that two strains named IB-88 and IB-84, contain the genes to encode potential Parasporins; however the parasporal protein profile on SDS-PAGE not correspond with the previously reported. PCR products were cloned and the nucleotide sequence from IB-88 strain showed a high identity (98%) to Parasporins Class 2, while IB84 is very similar (97%) to Class 4. The CPE of protein extracts was evaluated in 96 well plates after 24h of exposure to MOLT-4 cells. The results showed that IB-84 has a CPE higher than IB-88 with a cell survival rate less than 5 %. The nucleotide sequences and in vitro assays results, suggest that both are two novel Parasporins with a high potential as therapeutic agent.
https://doi.org/10.1142/9789814405041_0030
Economic losses resulting from disease development can be reduced by accurate and early detection of plant pathogens. Early detection can provide the grower with useful information on optimal crop rotation patterns, varietal selections, appropriate control measures, harvest date and post harvest handling. Classical methods for the isolation of pathogens are commonly used only after disease symptoms. This frequently results in a delay in application of control measures at potentially important periods in crop production. This paper describes the application of both antibody and DNA based systems to monitor infection risk of air and soil borne fungal pathogens and the use of this information with mathematical models describing risk of disease associated with environmental parameters.
https://doi.org/10.1142/9789814405041_0031
Aromatic compounds comprised by BTEX, PAHs and PCBs belong among the pollutants of concern due to their widespread presence at low concentrations resulting in adverse impact on the food chain and on the human health. Our study is searching for a sensitive correlation between diffuse contamination and catabolic potential in-situ. Bacterial communities are capable to adapt quickly to increased pollution concentrations by increasing their biodegradation potential. Developing of sensitive quantification technique which is detecting minor changes in the concentration of degradation genes could allow a better control of the environmental quality. Examples for application on multiple localities with different types of diffuse pollution are presented.
https://doi.org/10.1142/9789814405041_0032
Strategies applied to bioremediation contaminated environments are necessary to identify limitations towards biodegradation and to predict remediation performance and thereby rule out technologies that may be inappropriate for the clean-up of the substances of concern. Respirometry applied to bioremediation offers a series of advantages for obtaining CO2 production data when compared to other procedures. It was possible to determinate information regarding the atmosphere’s CO2 concentration inside a respirometer containing petroleum products. Afterwards, the CO2 data obtained underwent an in depth statistical analysis by F test. There are some noticeable biodegradation similarity among some substances, such as weathered motor oil and gasoline. Such data provides reliability when revealing important information about how the biodegradation processes happens in those residual oils.
https://doi.org/10.1142/9789814405041_0033
A phosphate solubilizing fungus, Aspergillus awamori S36, was isolated from the rhizosphere soil of Sesamum indicum grown in semi-arid climatic conditions. The organism was able to solubilize various inorganic forms of phosphate at a wide range of temperatures. Amongst various insoluble phosphate sources tested, di-calcium phosphate (DCP) was solubilized the most, followed by tri-calcium phosphate (TCP). The solubilization was evident at all the temperatures but the performance was especially good in the range of 25–35°C. Phosphate-solubilizing ability was also measured in the presence of various carbon and nitrogen sources. Fructose was found to be the best carbon source, followed by maltose, glucose, whereas, amongst nitrogen sources, sodium nitrate supported maximum solubilization, followed by ammonium sulphate.
https://doi.org/10.1142/9789814405041_0034
This study surveyed the presence of bacterial pathogens in two sewage treatment plants (STPs), located in Comunitat Valenciana (Spain), focusing on dissemination and removal of Salmonella spp. Moreover, it investigated the resistance of Salmonella spp. to different commonly used antibiotics. The presence of faecal coliforms was also investigated. Results showed the presence of both types of microorganisms in the reclaimed water (after tertiary treatment). Microbial presence indicates that the plants are not sufficiently efficient at removing pathogens and faecal indicators. This is a Public Health issue, as in our geographical area regenerated water is used for agricultural irrigation.
https://doi.org/10.1142/9789814405041_0035
Hydrocarbon waste, including crude oil residues in tank bottoms represents an ongoing and growing environmental problem throughout the world as they are particularly persistent within the environment and have the potential to induce a vast array of serious negative health effects for all biological entities. Bioremediation offers a sustainable treatment that reduces the levels of a pollutant present in a soil, for example to sub-toxic concentrations or brings them in line with compliance criteria for safe use or for disposal. In so doing, the risk following release to the environment is ameliorated. The aim of this study was to assess the potential of a hydrocarbonoclastic bacterial consortium, isolated from previously contaminated environments to both survive in contaminated environments and degrade weathered crude oil. Significant changes in the waste oil occurred through incubation with the microbial consortia including, emulsification, loss of viscosity and reduced hydrocarbon content, particularly in the high carbon chain (C20-C70 region). Profiling of the microbial community using denaturing gradient gel electrophoresis confirmed the influence of the addition of the microbial consortia on enhanced diversity of the microflora. Sequence identity of the individual strains present in the microbial consortia identified Pseudomonas sp. as well as several non-cultured gamma-proteobacteria. The result highlights the potential of hydrocarbonoclastic bacterial consortia for use in bioremediation.
https://doi.org/10.1142/9789814405041_0036
The intensive use of glyphosate [N-(phosphonomethyl) – glycine] to control weeds in agricultural areas all over the world requires special attention due to its toxicity to non-target organisms. The use of microorganisms in the degradation and detoxification of glyphosate polluted sites in the environment is an efficient tool and bioremediation is a very useful option to conventional cleanup methods. The objective of this study was to isolate the best bacterial strain with the ability of degrading high concentrations of glyphosate, a common herbicide used in the world. Then, the ability of the isolate to degrade glyphosate under varying nutrient was evaluated. The glyphosate utilization of the bacterium was screened using mineral medium containing glyphosate as sole C, N, P or C, N, P and glyphosate along additional C, N, P sources. Of all isolated bacteria, Pseudomonas (aeruginosa) showed the ability to utilize glyphosate efficiently and was therefore used for further biodegradation studies. The glyphosate biodegradation by Pseudomonas (aeroginosa) showed significant differences among 5 nutrient medium. The comparative effects of glyphosate on the growth of the isolates showed that there was significant (P < 0.05) growth in the medium containing glyphosate as an additional source of C/N/P). No inhibition of growth was observed at higher concentrations. But the percentage of degradation in the above medium (58.9%) was significantly (P <0.05) less than media containing glyphosate as sole sources of P (90.4%) or N (71.3%) and the medium containing glyphosate as source of P, N and C (72.8%). According to the results revealed that the bacterium exhibited a high capacity to efficiently degrade glyphosate as phosphorus source. It was also observed that it could degrade 21.25 g/lit glyphosate after 96 h incubation completely. It can be concluded that application of such isolated bacteria with the potential of degrading pesticides from contaminated site, can be used to remediate soil contaminated with pesticide.
https://doi.org/10.1142/9789814405041_0037
Growth in biofilms is a general ability of microbial populations which are historically used in wastewater treatment. The basic aim of biofilm formation is the fixation of microorganisms at a given place as a means of stabilizing living conditions. In a biofilm environment, organisms are protected against negative environmental influences. Compared to dispersion growth, biofilms offer many advantages that allow their use in specific biological treatment of industrial wastewater. The crucial advantage is the increase in the residence time of biomass in biofilm reactors allowing concentrations of slow-growing microorganisms and the diffusion barrier of the biofilm which reduces the effects of toxicants and suboptimal physico-chemical conditions. The development of the biofilm depends on many factors, from the surface properties to the supply of nutrients and hydrodynamic forces in the bioreactor. The objective of many research projects in the field of wastewater treatment is to technologically improve the biomass carrier. The final requirements are excellent colonization, high cleaning efficiency given the maximum specific surface area, optimal density and ease of production. Based on these crucial parameters the Technical University of Liberec has begun the development of a new type of carrier which is based on the use of polymeric nanofiber materials. This has resulted in a yarn which consists of a carrier fiber with a layer of nanofibers (the diameter of the nanofibers is in the order of hundreds of nanometers). The clear advantages of nanotechnology are a high protected specific surface area which promotes the microbial population during initial adhesion to the surface of the carrier and also during future development, protection of the population from surrounding adverse effects, promoting the supply of nutrients and supporting the compactness of the biofilm. The aim of the article is to highlight the possibilities and potential of biofilms with the presence of a composite nanofiber carrier.
https://doi.org/10.1142/9789814405041_0038
The content of ten metals in 15 non-human pathogen bacterial strains grown under 4 different nutrient condition treatments (C-limited, P-limited, N-limited, and Fe-limited) was determined. Results indicated that, independent of the nutrient limitation treatment, the highest metal values in the bacteria were always for iron (Fe), zinc (Zn) and manganese (Mn), and the lowest values were for vanadium (V). Large differences among the species (>1 or 2 orders of magnitude for Fe, chromium (Cr), and Mn) were found in the metal content within a particular nutrient treatment. Significant differences between the species were found for 5 out of 10 of the metals (cobalt (Co), Mn, Fe, nickel (Ni), and copper (Cu)) when comparing each metal content through the species. The content of iron in the Gram + bacteria Bacillus megaterium, B. subtilis and Enterococcus faecium was much higher than in the other bacterial species studied. The implications of these results are considered in the context of literature reports suggesting that the expression of virulence pathways by some bacteria may be regulated by iron.
https://doi.org/10.1142/9789814405041_0039
Yeasts are present throughout the spontaneous fermentation of table olives, and can have a great influence on the final product. For this reason, yeasts could be used as starter cultures in order to improve the quality of table olives. The aim of the present work was to study the effect of the growth conditions on the behaviour of yeast isolated from table olives. In this study, 17 yeast strains obtained from table olives, and belonging to various species of the Candida, Debaryomyces, Kluyveromyces, Pichia and Saccharomyces genera, were characterized by their behaviour in different culture conditions (NaCl and pH). Moreover, the flocculation capacity was studied, and interactions between yeasts and lactic acid bacteria were analyzed. Significant differences were found when yeasts were grown in culture media with salt concentrations between 7% and 12%, and pH between 3.5 and 7. Most of the yeasts analyzed could be useful as starter cultures to enhance the control of table olive fermentation, and hence obtain a high quality final product.
https://doi.org/10.1142/9789814405041_0040
Many plants of genus Prosopis (Leguminosae) are known to be of medicinal value because of increasing bacterial resistance against antibiotics and reported side effects of drugs ,researchers are trying to find new drugs and its natural source. In this study antibacterial activity of Prosopis juliflora was tested in -vitro against six gram positive and negative bacteria by paper disk diffusion and well methods.
In this purpose the methanolic extract at different concentrations (0.05, 0.1, 0.2, 0.3, 0.4 mg ml −1) against Staphylococus aureus, Micrococcus loteus, Bacillus cereus, Shigella sonee, Pseudomonas aeruginosa and Escherichia coli were tested.
Comparison were made with Amoxicillin and Methicin.Results showed that Pseudomonas aureginosa had the maximum resistant and Micrococcus luteus had the less resistant against this extract.
Further work needs to be done in this extract including fractionation to isolate active constituents and subsequent pharmacological evaluation.
https://doi.org/10.1142/9789814405041_0041
Numerous additives of vegetal source are currently used for the production of “green” eco-polymers. Officinal herbs represent a precious font of polyphenols and antioxidant biomolecules with effective activity against pathogen and unwanted microorganisms. This study was focused on the use of rosemary extract and Polyvinyl alcohol (PVA) to create a polymeric mixture with antimicrobial activity against different pathogen bacteria, for packaging applications. Thus, a series of PVA-rosemary extract polymers, having different concentration of the vegetal extract, was prepared. Samples were tested against some pathogen Gram positive and Gram negative microorganisms by the halo test on agar plates. Polymeric mixture revealed a dramatic antimicrobial activity against all microorganisms tested, also when the lowest amount of the vegetal extract was used. Free extracts or PVA only were absolutely ineffective as antimicrobial agents.
https://doi.org/10.1142/9789814405041_0042
Apple juices are described as potential inhibitors of oxidative stress preventing chronic disorders such as cancer and cardiovascular disease. Accordingly, the main intention of this study was to evaluate the influence of Golden Delicious apple juice, from Beira Alta, Portugal on cell proliferation of S. cerevisiae UE-ME3 exposed to oxidant, vanadium pentoxide. The results show that 2.0 mM vanadium pentoxide induced cell death, detected by a decrease in cell viability (cfu) and ALP activity, as well as, a significant increase of ROS and GSH contents, GSH/GSSG ratio and GR activity. Despite also occur a rise of free radical scavenger in citoplasm (DPPH) in cells exposed to vanadium, this response was not adequate to preserve its viability. Nevertheless, the apple juice caused a protector response, increasing cell viability and ALP activity, as well as, decreasing ROS content in S.cerevisiae grown in presence of V2O5. We assume that this partial reverse effect depends on phenolic compounds in apple juice, which amend the response mediated by glutathione.
https://doi.org/10.1142/9789814405041_0043
The objective of this study was to evaluate the effectiveness of two natural antimicrobials agents incorporated into polysacharides edible films against the common spoilage flora on cooked pork loin. First, different levels of rosemary extract and rosemary plus Pediococcus acidilactici extract diluted in polysacharide films were sprayed on cooked pork loins surface in order to tester their sensory characteristics. Once the antimicrobial level was selected, cooked pork loins were manufactured, sliced, placed in trays and randomly divided into four groups: batch control (cooked pork loins vacuum packed), batch P (cooked pork loins sprayed with polysacharide film on the surface and vacuum packed), batch RP (cooked pork loin sprayed with rosemary extract diluted in polysacharide film on the surface and vacuum packed) and RPP (cooked pork loin sprayed with rosemary plus Pediococcus acidilactici extract diluted in polysacharide film on the surface and vacuum packed). All groups were stored under illumination at 2°C and at 0, 7, 14 and 21 days of storage two packs of each batch were used for carried out microbial analyses. In general, the microbial counts increased steadily during storage. Psychrotrophic and anaerobic bacteria counts reached values of 7 log cfu/g at 21 days. Regarding batches, there were not differences in log values of microbial counts among control and the others, which indicated that no antimicrobial activities were observed through storage. This fact may be due the amount used was not sufficient for inhibition.
https://doi.org/10.1142/9789814405041_0044
Aerial yam (Dioscorea bulbifera) is one of the varieties of yam cultivated in Nigeria but less consumed. To diversify the processing methods and encourage its other uses, the yam was subjected to fermentation process for 5 days. The microbial, pH and titratable acidity (%TA) of the fermenting mash as well as the proximate composition of the fermented and unfermented flour were assessed. The total viable counts increased from 1.64 × 108 cfu/ml by day 3 and decreased to 7.62 × 102 cfu/ml at the end of fermentation. While the pH decreased, the TA increased at the end of fermentation. The prevalent microbial genera involved in the fermentation were Lactobacillus, Bacillus and Penicilium. The proximate composition of the fermented flour differed significantly (p<0.05) from the unfermented with increased protein content from 6.78g/100g (control) to 9.26g/100g. Fermentation improved the nutritional and microbial quality of aerial yam flour.
https://doi.org/10.1142/9789814405041_0045
The microbial load on sheep/beef carcasses was investigated in El-Harrach abattoir in Algiers. A total of 210 carcasses were studied using wet/dry swab technique. The samples were processed for total viable count (TVC), total coliforms (TC), fecal coliforms (FC), and Salmonella spp.
The recorded average charges were relatively high, especially for the bovine species. On 90 ovine and 70 bovine carcasses being the subject of Salmonella research, one ovine carcass (1, 11%), and 7 bovine carcasses (10%) were contaminated. 13 strains of Salmonella were detected, the dominating serotype was S. Anatum (76, 92%), followed by serotypes of subspecies arizonae (15, 38%), and S. Abortus ovis (7, 69%). The area of the breast and the posterior face of the foreleg were the most contaminated zones for the entire studied flora.
https://doi.org/10.1142/9789814405041_0046
A partial characterization of an intracellular β-glucosidase activity from a strain of Oenococcus oeni isolated from wines from the Spanish origin appellation “Ribeira Sacra” has been made. From cell-free extracts (crude extracts) some biochemical parameters of this activity have been analysed (ie. optimum temperature, optimum pH, effect of putative substrates, inhibitors and activators, enzyme location, stability of the enzyme). The results obtained are presented and discussed in this document.
https://doi.org/10.1142/9789814405041_0047
Listeria monocytogenes is a foodborne pathogen of great interest due to its unique epidemiological features, its ubiquity and the severity of the diseases it causes The purpose of this work was to study the presence of Listeria monocytogenes in modified-atmosphere-packaged (MAP) vegetables available to consumers in Valencia by normalized cultural method and multiplex PCR technique. L. monocytogenes was detected in a total of 23 among 70 MAP vegetables samples. Cultural method allowed the isolation of three strains of this pathogen while PCR yielded L. monocytogenes positive results in 22 samples.
https://doi.org/10.1142/9789814405041_0048
Microbial spoilage of seafood is an issue of global concern, resulting in high economic losses in the seafood industry. The present study describes the development of a DNA microarray for the detection of pathogenic and spoilage bacteria. The applied methodology was based on the use of the ligation detection reaction coupled to a universal array. Oligonucleotide probes were designed based on the 16S rRNA gene, using the informatics tool ORMA. For that, bacterial species with importance in seafood-spoilage and foodborne intoxications were considered. After testing specificity of the probes in-silico, four probes were selected and synthesized, being specific for Aeromonas spp., Pseudomonas spp., Shewanella spp. and Morganella morganii. For the validation of the probes, 18 strains from type culture collections were tested. The probes resulted to be high specific and sensitive. In conclusion, the designed probes, coupled to the universal array, could be applied for the rapid, efficient and accurate identification of these bacterial species, exhibiting special relevance in seafood spoilage.
https://doi.org/10.1142/9789814405041_0049
Listeria monocytogenes is an important foodborne pathogen. Microbial food safety issues have emerged as a major public health concern worldwide. Also, the mortality rate is high in immunocompromissed. This indicates that L. monocytogenes it is one of the main foodborne pathogens. The classic detection methods for pathogens generally involve colony isolation on selective media, use of biochemical tests and serotyping using antibodies against specific bacterial antigens. These procedures are laborious and time consuming. Various molecular diagnostic techniques have been used for detection foodborne pathogens. PCR-based methods could be a good alternative to traditional culturing techniques since they are rapid, sensitive, specific and allow accurate quantification. The aim of this study was to optimize the conditions for a real-time PCR method to enumerate L. monocytogenes in cheese, and the applicability of this process will be tested on cheese and contact surfaces to monitor L. monocytogenes.
https://doi.org/10.1142/9789814405041_0050
Clostridium botulinum is an obligate anaerobic, endospore-forming bacterium that produces a lethal neurotoxin called botulinum neurotoxin (BoNT). BoNTs are one of the most powerful biological and chemical substances known, and are responsible for a paralytic disease known as botulism, which is characterized by severe flaccid paralysis. BoNTs are divided into seven toxin types, A to G, according to their antigenic properties. Toxin types A, B, E, and F cause human botulism.
The presumptive identification of the toxigenic strains and typing of BoNT were based on an enrichment step and subsequent detection of the toxin by in vivo mouse bioassay. This technique is highly sensitive and specific but laborious, time-consuming, and costly and raises ethical concerns with regard to the use of experimental animals. Molecular biological methods based on the detection of BoNT genes in any neurotoxigenic microorganisms would be an ideal alternative. However, there have been few reports of the use of a single PCR primer set for simultaneous detection of BoNT genes of more than one type causing human botulism.
In this study we report the development of a method for simultaneously detecting C. botulinum types A, B, E, and F. With the comparison of the sequences of C. botulinum types A, B, E, and F, the Biological Defence Unit has developed specific primers for detecting simultaneously the four types.
https://doi.org/10.1142/9789814405041_0051
This study was undertaken to measure the survival and death of L. monocytogenes from a high level inoculum in dry cured iberian meat products (dry cured ham, dry cured loin, “salchichón” and “chorizo”) as affected by storage temperature. The dry cured meat products were sliced and inoculated with a L. monocytogenes culture to obtain counts that reached 104 cfu/g in the products. Then, meat products were vacuum-packed and stored at 4, 8 and 12°C for up to 365 days. Physico-chemical analyses (pH and aw) were carried out on day 0 and microbiological analyses (enumeration and detection of L. monocytogenes) were performed at 0, 90, 180 and 365 days. The results indicated that the physico-chemical characteristics of evaluated products the inclusion of antimicrobial ingredients in the product and the storage conditions did not allow the survival of L. monocytogenes. Besides, the results suggested that the temperature and the type of dry cured meat products influence on the death rate of L. monocytogenes.
https://doi.org/10.1142/9789814405041_0052
Foodborne pathogenic microorganisms as Listeria monocytogenes have been linked to cases of foodborne infection in ready-to-eat fresh vegetables. Chlorination is considered the main way to minimize the transmission of pathogens from fresh products. The objective of this work was to study the effectiveness of washing lettuce leaves with sodium hypochlorite at different doses and times for the reduction of L. monocytogenes and natural microbiota viable cells. L. monocytogenes CECT 936 was used to inoculate fresh-cut leaves of lettuce by dipping inoculation model to represents fresh or recent contamination of the product. Two types of washing were assessed: dipping and shower, with chlorine concentrations of 4, 8, 40, 400, 600, 800 and 1200 ppm. The results showed that domestic washing of fresh vegetables with potable tap water or a few drops of bleach for five minutes, prior to its consumption constitutes a fundamental stage to guarantee the consumers safety, since it can reduce small microbial loads that could be present in lettuce due to slight deviations in the control of the food chain.
https://doi.org/10.1142/9789814405041_0053
Research to measure the fly density and environmental factors in street vendors foods was done along the Margonda Avenue, Depok City, West Java Province, Indonesia used crossectional design.
A total of 100 street vendors were selected randomly, from which different types of foods were sampled for fly density and Escherichia coli. Fly grill was used to measure the fly density, otherwise the analysis of E. coli using the Most Probable Number (MPN) method. Also, environmental factors of street vendors and personal hygiene of food hanlers were observed. Analizing of the data used Chi Square Test and Logistic Regression.
It was found that the fly density was a quite high (more than 6) with the average in each location were 9.38 in Point-1, 8,53 in Point-2, and 10.33 in Point-3. Forty one (41) percent of samples contaminated by E. coli and 14% contaminated by Salmonella. The average flies’ density around the street vendors area were high. Almost half of the food sold by street vendors was contaminated by E. coli, some contained other pathogens such as Salmonella. Based on the statistical test, there was an association between flies density and E. coli contamination on food. But statistically, high flies density will prevent contamination as much as 3.86 times (OR=0.26).
https://doi.org/10.1142/9789814405041_0054
Fungal contamination of food may be one of the more pervasive and seldom recognized cause of disease. Fungi produce mycotoxins that are versatile and potent causes of disease. Mycotoxins can cause acute and chronic illnesses, induce cancer, and damage vital organs. The purpose of this study was to isolate filamentous fungi from some foods and testing for mycotoxin production and finding the effects of some antifungal agents on to these isolates. Twenty-one fungal isolates were obtained from some of supermarket foods such as cheese, yogurt and olive. The majority of the isolates identified belong to the genera Penicillium sp. and Aspergillus sp. Taxonomical identification was based on the morphological characteristics of the fungi as observed under the microscope by using diagnostic literatures. These isolates were tested for mycotoxin production. Three of the fungal cultures were moderately toxigenic that including Penicillium sp. Effects of antifungal agents such as sodium nitrate, potassium sorbate, nisin, sodium propionate which can use food production prosess according to Turkish Food Codex were tested on fungi isolates. Potassium sorbate was most influential antifungal agent on our isolates.
https://doi.org/10.1142/9789814405041_0055
The following sections are included:
https://doi.org/10.1142/9789814405041_0056
The study was aimed at producing an acceptable, health promoting and affordable yoghurt analogue from blends of tigernut-, soy- and groundnut milk. Different blends of tigernut, soy and groundnut milk (1:1:1; 1:2:1; 1:1:2; and 2:1:1) respectively were formulated and inoculated with 2% (w/v) commercial starter culture containing Lactobacillus bulgaricus; L. acidophilus and Streptoccus thermophilus). Samples were incubated at 45°C for 6h and then for 24h. Thereafter, samples were pasteurized at 65 °C for 30 minutes and subsequently refrigerated for 21d at (4 ± 1°C). Samples were subjected to microbiological analysis, physico-chemical and sensory evaluation at different stages of preparation and storage. Results show that the Lactic acid bacteria (LAB) count increased from (3.6 × 105 − 9.9 × 106) to (8.4 × 105 − 10.0 × 106) in all the samples during the first 7 days but it decreased thereafter. TTA increased from 0.24 − 0.25 to 0.58 − 0.94 after 21d of refrigerated storage. Responses elicited from tasters reveal that there was no significant difference in taste, flavor appearance and overall acceptability of the fermented milk samples (p > 0.05). The study has established that acceptable and safe fermented drink could be produced from different blends of milk from tigernut, soybeans and groundnut.
https://doi.org/10.1142/9789814405041_0057
In this work, the mycobiota of wheat grain from Spanish factories that manufacture that cereal for human consumption was studied. Special attention was paid to the fungal species known as potential producers of aflatoxins, ochratoxin A, zearalenone, fumonisins and trichothecenes. Two hundred and thirty seven wheat grain samples grown in different agro-climatic regions of Spain were analyzed. One hundred kernels per sample were studied. Aspergillus, Alternaria, Penicillium, and Fusarium were present in 100 %, 94 %, 88 % and 51 % of the samples, respectively. The most important mycotoxigenic fungi isolated from wheat samples were species of Aspergillus in sections Flavi, Nigri and Circumdati, Fusarium graminearum, F. avenaceum, F. culmorum, F. tricinctum, F. equiseti, F. sporotrichioides and F. poae. In this study, differences in mycobiota related to the geographic origin of the wheat samples were found.
https://doi.org/10.1142/9789814405041_0058
Fusarium graminearum and F. culmorum are the major pathogens associated with Fusarium head blight or Fusarium ear blight of wheat in Spain. They may cause yield loss or produce mycotoxins in the grain. Climate change can have direct impacts on Fusarium head blight severity in wheat crops, since weather factors will affect epidemics, the relative proportions of species of ear blight pathogens responsible and the production of type B trichothecenes. The objective of the present study was to assess how temperature, aw and strain can affect the production of type B trichothecenes by isolates of F. graminearum and F. culmorum isolated from wheat grown in different agro-climatic regions in Spain. A full factorial design was used and a statistical software package helped us to interpret data. The isolates assayed belonged to the deoxynivalenol/3-acetyl deoxynivalenol chemotype. Water activity of cultures, within the studied range (0.96−0.98 aw), temperature (16, 22 and 28 °C) and strain affected significantly mycotoxin production. The highest mean levels (of three assays) of deoxynivalenol and 3- acetyl deoxynivalenol were produced by the isolate Fcu7 at 0.98 aw and 28 °C (1468.5 μg/Kg) and 16 oC (497.5 μg/Kg), respectively. ANOVA revealed significant interactions between temperature and strain. Strategies to reduce increase on production of deoxynivalenol in wheat by F. graminearum and F. culmorum associated to global climate change were found to be necessary
https://doi.org/10.1142/9789814405041_0059
The controversial nature of Enterococcus genus is due to the great variability among pathogens, spoilage and apparently safe strains. The current research focuses on the study and characterization of Enterococcus strains involved in nosocomial infections. However, little research has been carried out on Enterococcus strains in foodstuffs. In this work, 54 strains of different species of Enterococcus have been characterized by means of MALDI-TOF MS analysis, getting highly specific mass spectral fingerprints. Genus-specific peaks and peaks common to certain bacterial species of Enterococcus have been identified. Thus, three protein peaks at m/z 4426, 4732 and 6401 were marked our as genus specific biomarkers, this is, proteins that are characteristic for each species of Enterococcus. The approach described in this study leads the way toward the rapid and specific identification of different strains and species of Enterococcus in food based on molecular protein markers with aiming the early detection of pathogenic strains and strains implicated in food poisoning and in food spoilage of the Enterococcus genus.
https://doi.org/10.1142/9789814405041_0060
Biocides are widely used in the food industry, and biocide-resistant bacteria are a matter of concern. Yet, little is known about the levels of biocide resistance in bacteria from vegetable foods. In the present study, a collection of bacteria isolated from vegetable foods was challenged with biocides. Inhibition of bacterial growth by increasing biocide concentrations was examined. The most effective biocide among quaternary ammonium compounds was benzalkonium chloride. The bacterial group most sensitive to this biocide was presumptive staphylococci followed by azide-resistant bacteria and Bacillus cereus. The Pseudomonads and Enterobacteria were the less sensitive. Cetrimide was much less active, especially on Enterobacteria, although it showed strong inhibition against Listeria. A similar trend was observed for hexadecylpyridinium chloride, although this compound was also more active on staphylococci. Polyhexamethylen guanidinium seemed to be the most active among all biocides tested, with strong inhibitory effects against all bacterial groups. In contrast, the bis-phenols triclosan and hexachlorophene seemed to be the less active in their capacity to completely inhibit bacterial growth.
https://doi.org/10.1142/9789814405041_0061
The effect was studied of several yeast strains of the genera Saccharomyces, Pichia, and Kluyveromyces on the persistence of four pesticides (pyraclostrobin, dimethoate, oxamyl, and pymetrozine) in brine during the fermentation process of vegetable products. The growth of yeast strains in a synthetic brine in the presence of the pesticides was recorded with a Bioscreen C kinetic growth reader and compared with their growth in a control brine without pesticides. After incubation for 7 days with the yeast strains, the concentration of pesticides in the synthetic brine was determined. Prior to this pesticide assay, the brines were centrifuged to removing the yeast pellets. The pesticides were determined in both yeast-free brine and yeast pellets and compared with the control consisting of sterile brine with pesticides. A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used to extract the pesticides, which were assayed by LC-MS. The effect of the yeasts on the concentration of the four pesticides in synthetic brine depended on the yeast strain, and was clearest on pymetrozine and pyraclostrobin.
https://doi.org/10.1142/9789814405041_0062
The scope of this paper was the utilization of polyphenol-based supplements isolated from olive mill waste (OMW) in lactic acid fermentation and in media for the cultivation of lactic acid bacteria (LAB), in order to stimulate biomass growth and lactic acid biosynthesis in LAB used as starter cultures in fermented dairy and meat products. At 500-1000 ppm polyphenol concentration in liquid culture media a clear stimulation of certain lactic acid bacteria was observed (mostly for Lactobacilli),which probably occurs via a non-specific stimulation of key biosynthetic enzymes. This stimulatory effect of polyphenols is novel in the literature and can have many industrial applications, since a higher growth and acid biosynthesis rate of LAB cultures is important in industrial fermentations (e.g. lactate production) to improve productivity, and to ensure sufficient and fast growth of starter cultures in fermented foods.
https://doi.org/10.1142/9789814405041_0063
Transformations of nerol and geraniol with Aspergillus niger in Yeast-Malt (YM) medium are reported. A. niger was pre-cultured in 300 ml of YM medium for 3 days. After that, 0.4mmol nerol or geraniol was added to the culture and the culture was continued. The formation rate from nerol was far faster in the Czapek-Dox medium than that in YM medium, though the growth rate of A. niger was faster in YM medium than that in Czapek-Dox medium. The transformation of nerol with A. niger in the YM medium 1 day, ω-hydroxynelol was produced at first. After 10 days, the amount of ω-hydroxynerol was decreased and ω-hydroxylinalool was produced. On the other hand, in the case of the transformation in the Czapek-Dox medium, ω-hydroxylinalool was produced, whereas ω-hydroxynerol was not produced. Therefore, the ω-hydroxylinalool production pathway from nerol with A.niger were different from the cases in these two media. Transformation of linalool with A. niger was also examined in YM medium. From the result of this transformation, ω-hydroxylinalool was also mainly produced.
https://doi.org/10.1142/9789814405041_0064
Lactobacilli belong to the group of Lactic Acid Bacteria (LAB), extensively utilised in the contemporary food industry. These bacteria are mainly used as natural acidifiers, for the inoculation of bulk quantities of milk and vegetables, in order to produce a variety of fermented products. As such, large quantities of their biomass, produced in cost effective enviromentaly friendly nutrient media, are necessary. Furthermore, during their growth, they naturally produce antimicrobial substances, called bacteriocins or lantibiotics. Due to the constantly developing need for natural food preservatives, bacteriocins deriving from Lactobacilli metabolism, function and activity have been extensively investigated.
The possibility of producing these substances in mass quantities was investigated through several techniques. Three known bacteriocin producing strains of Lactobacilli, were carefully selected, L. plantarum NCIMB 8014, L.casei NCIMB 11970 and L.lactis NCIMB 8586. They were grown into simple batch cultures without pH control, where their physicochemical needs were determined. Through the determination of the optimum nutritional conditions for their propagation an optimised growth medium occurred. A simple, liquid turbidometric method was developed to test the bacteriocin productivity of these strains, on the developed media. The antimicrobial activity and potency of the bacteriocins produced, were tested against the target strain L.delbruckii subsp.lactis NCIMB 8117. In an effort to facilitate the extraction of bacteriocins from the fermented broths it was decided , to fabricate a nutrient medium, that would contain, low molecular weight nitrogen sources and equally support high production of bacteriocins and large yields of biomass.
In order to achieve that, the optimised medium was then filtrated via ultrafiltration membrane modules of 30 and 4 kDa MWCO , in an effort to simplify the medium and facilitate the extraction of the produced substance. The medium’s efficiency in supporting the growth and the bacteriocin production of the bacilli was tested and comparative studies between filtrated and unfiltrated media were done. The filtered medium, containing low molecular weight nutrient sources, was proven to successfully support growth and bacteriocin production.
https://doi.org/10.1142/9789814405041_0065
This work was devoted to improve the nutritional quality and the safety of pigs fermented liquid feed (FLF) by setting up a directed microbial ecology approach The optimal range of fermentation parameters (temperature, amount of residual liquid feed) favouring the development of the lactic microflora and inhibiting the growth of undesirable and pathogenic bacteria in the feed was researched. The efficiency of a selected strain (Pedicococcus acidilactici) as culture starter and barrier flora was also investigated. In parallel, the community composition and cell density in the biofilms developed mainly on the pipeline surfaces were recorded. It was found that it closely reflect the microbiology of the feed thus validating the followed approach.
https://doi.org/10.1142/9789814405041_0066
Liconic Instruments’ automated −80°C Tube Store becomes an extremely useful, simple and intuitive system for a long-term storage of microorganisms at optimum conditions without the loss of their valuable properties. This ultra low temperature store is based on the chest freezer principle. Samples are loaded into the chamber via special interface unit (−20°C). This ensures a stable temperature and dry conditions into the storage compartment. Computer passwords used by depositors during the sample load operation ensure an authorized access to commercial strains of microorganisms. Unique “real time” online database of microorganisms has been organized on basis of the STC Tube Store Sample management software, which contains all information about the strains deposited: description, location in the store and movements of each sample. Such kind of store gives possibilities to intensify the search of new microbial cultures, keeping in mind the huge soil microbe’s biodiversity and a necessity to mobilize genetic resources of microorganisms for an agricultural production.
https://doi.org/10.1142/9789814405041_0067
Natural glycopolymers are widely distributed in plants, animals as well as microorganisms. Many of them have found applications in industrial fields such as food texture as well as human health. The demand for such molecules is constantly increasing, leading to the interest in new polysaccharides with innovative properties. Vibrio diabolicus is a marine bacterium producing an exopolysaccharide (EPS), HE800, which shows structural homology with hyaluronic acid. As a glycosaminoglycan mimetic, its properties in bone and cartilage regeneration, angiogenesis, and osteosarcoma treatment are currently under study as promising applications. The use of polysaccharides for human health requires the control of characteristics among batches produced. Molecular weight is a particularly important parameter that needs to be stable between production batches.
In this context, the aim of our study is to gain insight into the molecular mechanisms of polysaccharide biosynthesis. Bioinformatic analysis of the genome of Vibrio diabolicus has identified genes potentially coding for the proteins involved in exopolysaccharide biosynthesis. The results suggest that the biosynthesis mechanism in Vibrio diabolicus is similar to that of groups 1 and 4 capsular or lipopolysaccharides produced by Escherichia coli.
https://doi.org/10.1142/9789814405041_0068
Fatty acids (FA) are structural constituents of cell membranes, play functions and energy metabolic reserves, besides forming hormones, and bile salts. Several studies suggest that fatty acids are beneficial to human health, preventing cardiovascular disease, colon cancer, and immune diseases. Filamentous fungi of the Mucoralean order are known to produce fatty acid of omega 6. In this sense, we investigated the production of polyunsaturated fatty acids, PUFAs by Cunninghamella elegans UCP 542 (Mucoralean fungus), using glycerin as alternative substrate carbon source, in order to minimize the production of costs.
https://doi.org/10.1142/9789814405041_0069
The biosurfactants are compounds of microbial origin that exhibit surfactant property, low toxicity and high biodegradability. In this study, biosurfactant production by Mucor circinelloides was studied, using a factorial design of 22, to evaluate the influence of the medium components and the combination of: apple peel and soybean oil post -frying supplemented with corn steep liquor (2%), pH 6.5. The Erlenmyers flasks were incubated at room temperature for 144 hours and static. The results showed that in all conditions tested there was a reduction of the surface tension of 44.9 mN/m to 33mN/m. However, the biosurfactant produced a promise emulsifier agent using diesel, motor oil, soybean oil post frying, and motor oil. The best results showed emulsification index at the central point using soybean oil after frying (93.6%.), engine oil burning (80%), and motor oil (78%). We observed an increase in pH (8.0) in all experiments. The results indicated the feasibility of production of biosurfactant with emulsifying properties, and low-cost medium formulated with apple peels and soybean oil.
https://doi.org/10.1142/9789814405041_0070
An indigenous biosurfactant was produced by Pantoea sp isolated from the effluent of ice cream industry. The microbial growth and bissurfactant production was used the medium containing the pineapple peel juice and corn oil. The biosurfactant showed a reduction of distilled water of 69 to 36mN/m. The tensio-active produced stable emulsions with petroleum, motor oil, diesel, gasoline, kerosene, soybean, corn, and sunflower oils. The preliminary chemical characterization revealed that the biosurfactant consisted of extracellularly proteins, lipids and carbohydrates. The biosurfactant was stable during exposure to salinity of 2.5 to 5% of NaCl, higher temperature (121°C for 60min), and a range of wide pH (6.0 to 8.0). The CMC of the biosurfactant produced by Pantoea sp was approximately 1%, and the toxicity using Artemia salina showed lower toxicity. The biotechnological results demonstrated the higher potential of Pantoea sp to biosurfactant production, as well to the low-cost medium constituted by pineapple peel and corn oil.
https://doi.org/10.1142/9789814405041_0071
The aim of this work was investigated the biotechnological potential of R. arrhizus to produce biomass and biosurfactant using soluble agro industrials substrates as rice bran husks and corn steep liquor. The biosurfactant production was analyzed using liquid metabolic free cells measuring surface tension water reduction and emulsification index (E24) using five oils. The best result was obtained in the assay 4 [8% of corn steep liquor and 3% of rice bran husks], biomass production of 9.10g/L. The liquid metabolic of free cell showed a water surface tension reduction of 26.5 mN/m in the assay 6 [6% of corn steep liquor and 2% of rice bran husks], and the best emulsification index of 63.8% in palm oil in the assay 5[6% of corn steep liquor and 2% of rice bran husks]. In addition, R. arrhizus produced biosurfactant when grown in batch cultures with corn steep liquor and of rice bran husks as nitrogen and the energy source. In view of the possible use of biosurfactants, our goal was to develop a continuous production process.
https://doi.org/10.1142/9789814405041_0072
This study aimed to evaluate the biosurfactant production and their stability against pH, temperature and salinity, industrial waste being used as a source of carbon and nitrogen. We used the yeast R. glutinis. The production was performed in Erlenmeyer flasks (250 ml) containing 100 ml of DCCR average production according to an experimental. The best condition, based on surface tension, was selected for testing interfacial tension, emulsification index, stability and extraction. We determined the surface and interfacial tension of the net metabolic and cell-free and obtained from 34.01 mN/m and 14.7 mN/m, respectively. Were obtained emulsification index of 70% for motor oil and 100% for burning waste vegetables. The results show the importance of waste as an alternative to the production of biosurfactant and the biosurfactant ability to remain stable under the conditions tested.
https://doi.org/10.1142/9789814405041_0073
Biosurfactant production by two strains of Candida glabrata (UCP 1002 and UCP 1556) was performed using a biotechnological process using industrial wastes as sources of carbon and nitrogen. The first fermentation occurred in the control medium, and the second fermentation in the same way, replacing glucose by whey (carbon source), and corn steep liquor by peptone (nitrogen source) following the conditions used in the experimental design (DCCR). The best results obtained for biosurfactant production in both strains were observed in the assay 8 (25% whey and corn steep liquor 11.02%), the surface tension reduction was from 70 to 31.2 mN / m in C. glabrata (UCP 1002). For the rate of emulsification, the best results in both strains were obtained in the assayt 7 (25% whey and corn steep liquor 4%), with a better rate of emulsification of 90% in C. glabrata (UCP 1556). The biosurfactant showed greater stability, determined by surface tension and was produced by C. glabrata (UCP 1556) against to a wide range of salt concentrations and at different pHs.
https://doi.org/10.1142/9789814405041_0074
This paper present the Tropical Culture Collection CCT to show how it is and the areas it is involved: Applied microbiology, Culture and preservation methods, Environmental protection, Industrial microbiology, Fermentation, Freeze drying and so on, and also about the services and training courses it offers: Management of a culture collection, Culture and preservation methods, Propagation, Preservation, Storage services (Bacteria, Yeasts, Fungi), Distribution (Bacteria, Yeasts, Fungi).
https://doi.org/10.1142/9789814405041_0075
Cellulases are enzymes with a high potential of biotechnology and is currently being applied as biocatalysts in a series of industrial processes and can be produced by different fermentation processes. Brazilian tropical environments show a rich biodiversity, making it promising to search for new microorganisms with biotechnological applications, especially lignocellulolytic fungi and bacteria, which are extremely important. Thus, this study aimed to evaluate the production of cellulase (CMCase and FPase) by the strain Penicillium sp. IS-07 in submerged fermentation using sugarcane straw as a carbon source and corn steep liquor as a nitrogen source, using the methodology of factorial design 25−1, varying temperature, agitation, inoculums concentration, carbon and nitrogen source concentration. The measurement of enzyme activity was determined by quantification of reducing sugars by DNS method. The best enzymes production of CMCase (2,274.0 U / L) and FPase (128.0 U / L) was detected after 5 days of culture, in assays 16 and 8, respectively, and the data statistically significant at 10%. This study demonstrates that the strain Penicillium sp. IS-07 features high production of cellulase and potential for optimization of enzyme production, in order to develop products with biotechnological potential.
https://doi.org/10.1142/9789814405041_0076
Chitin and chitosan hold a great economic value as due to their versatile biological activities and chemical applications, mainly in medical. Recent advances in fermentation technologies suggest that the cultivation of selected fungi can provide an alternative source of chitin and chitosan. The amount of these polysaccharides depends of the fungi species and culture conditions. Filamentous fungi have been considered an attractive source of chitin and chitosan for industrial applications because their specific products can be manufactured under standardized conditions. However, to optimize the production of chitin and chitosan from fungi, it’s usually used complex or synthetics cultures media, which are expensive. It’s becomes necessary to obtain economic culture media that promote the growth of fungi and stimulate the production of the polymers. Economic microbial culture media normally use vegetables components. Microbiological process was studied for production of chitin and chitosan by Cuninghamella elegans grown in Coconut water. A laboratory assay was carried out to evaluate the Cunningamella elegans growth using Coconut water during 96 hours, under agitation (125 rpm) at 28°C. The mycelial biomass was determined following lyophilization. Chitin and chitosan were extracted by alkali-acid treatment, and the polymers were characterized by Infrared spectroscopy and viscosity. A higher production of biomass can be verified in 96 hours of growth corresponding to 2,19 g/L. In addition, the best yield of chitin (389mg/g) and chitosan (129 mg/g) are obtained in 48 hours and 96 hours of growth, respectively. Chitin and chitosan showed degree of deacetilation, respectively of 23% and 80% and viscosimetric molecular weight of chitin and chitosan 2.39 × 104 g/mol and 3.5 × 104 g/mol, respectively. The results suggest that Coconut water improves chitin and chitosan production and the mycelial biomass of C. elegans may be used as an alternative source of these polymers.
https://doi.org/10.1142/9789814405041_0077
Lovastatin is a natural statin produced primarily by Aspergillus terreus and Aspergillus flavipes. It competitively inhibits HMG-CoA reductase and prevents the synthesis of mevalonate, a committed precursor in the cholesterol biosynthetic pathway. The mechanism of inhibition and the use of lovastatin and its many derivatives, as a drug for the treatment of hypercholesterolemia have been extensively studied. However, the synthesis of lovastatin through the polyketide biosynthetic pathway has remained relatively un-investigated. In this work, we present a comparison of lovastatin biosynthesis when two different carbon sources, glucose and lactose, are used separately and in combination. The highest lovastatin concentration was obtained when the carbon sources were combined and a metabolic flux analysis was performed to determine the theoretical yield and energy demand under these conditions. Our results showed that while the carbon source influences the relative fluxes in the pathways driving growth of cells and lovastatin production, the metabolic state is defined by the oxygen uptake and energy status of the microorganism.
https://doi.org/10.1142/9789814405041_0078
The effect of different concentrations of iron on the Azotobacter chroococcum growth and PHB accumulation as well as on the characteristics of the isolated native PHB granules and the purified polymer was investigated under conditions of fed-batch fermentations. A new hydrophobic fluorescent P8 was used to study an effect of iron concentration on the bacterial cell and the isolated native PHB granules. An increase of the iron concentration in growth medium accelerated A. chroococcum growth and total PHB yield. The observed changes in P8/bacterial cells system fluorescence intensity under experiment conditions reflects alterations of the of cells physicochemical state. The increase of iron concentration in growth media Azotobacter chroococcum led to higher impurity of the recovered PHB granules samples and resulted in a lowering of tensile strength and elasticity of the polymeric films.
https://doi.org/10.1142/9789814405041_0079
The lipases of microbial origin represent the most widely used class of enzymes in biotechnological applications and organic chemistry. The fats present in the waste of ice cream have different types of fatty acids: saturated, monounsaturated and polyunsaturated. Factorial experiments allow subtle manipulations of a larger number of interdependent variables. Whilst the method has limitations, it is a useful method for streamlining research and letting powerful statistical methods highlight any correlations. This work study was conducted to select an alternative means for lipase production by B. licheniformis (UCP 1014) and then the formulation of an alternative means of production, using waste from ice cream industry media through a factorial design 24 in conditions variables. The assays occurred during 96h, 150 rpm, 37°C. The results showed that the media C indicating a lipase activity of 256 (U/mL) / min.
https://doi.org/10.1142/9789814405041_0080
This work presents first results of a new approach for the detection of biological contamination using the Surface Plasmon Resonance (SPR) spectroscopy. SPR sensors have been commonly employed for the detection of proteins, bacteria and chemical substances. However, only specific interactions can be detected so far that rely on specific and sensor immobilized receptor molecules. It is of importance to overcome this limitation as technical fluids like cooling lubricants, paints and varnishes often show contaminations with different strains of microorganisms. The here presented general approach will focus on a distinguished mode of action. The aim is an unspecific adsorption of bacteria and other microorganisms to differently processed metal surfaces. The processed sensor surface is characterized by means of contact angle measurements, scanning electron microscopy, and bacterial and fungal binding studies. Besides, one of the main advantages of the sensor is the usability in a multitude of liquids such as deeply contaminated emulsions and other technical fluids, providing a broad applicability of the sensor system.
https://doi.org/10.1142/9789814405041_0081
We have developed several practical sessions to introduce science secondary school students to microbiology and biotechnology. Alcoholic fermentation is frequently used in school lectures and experiments, but these experiments are rarely concerned with anything beyond ethanol production. In the present practical session, students were taught in the proper use of a microscope, microorganism manipulation, and staining techniques. Students learned concepts about microorganism growth, biochemical pathways and the use of enzymes in industry. This activity has strengthened the relationship between science secondary school students and teachers and university teachers and has contributed to improve general microbiology and biotechnology knowledge in society.
https://doi.org/10.1142/9789814405041_0082
In this work, we describe a new approach probing for protein-protein interactions in Saccharomyces cerevisiae using the Global Proteome Machine Database (GPMDB), an open access database derived from mass spectrometry experiments, to develop in silico analyses of protein interactions. Using Mnn10p as a control of a known protein complex in S. cerevisiae, we analyzed Mnn2p protein interaction partners with shared functions in a possible protein network.
https://doi.org/10.1142/9789814405041_0083
Chitin and chitosan hold a great economic value as due to their versatile biological activities and chemical applications, mainly in medical. Recent advances in fermentation technologies suggest that the cultivation of selected fungi can provide an alternative source of chitin and chitosan. The amount of these polysaccharides depends of the fungi species and culture conditions. Filamentous fungi have been considered an attractive source of chitin and chitosan for industrial applications because their specific products can be manufactured under standardized conditions. This research describes an experimental study of the influence of the glucose, thiamine and asparagine concentration on chitin and chitosan production by R. arrhizus. The effect of these factors or the interaction effects between these will be observed by factorial design analysis. For chitin and chitosan production suspensions of 108 sporangioles/mL of R. arrhizus was inoculated in Erlenmeyer flask containg Hesseltine and Anderson medium, varying glucose, thiamine and asparagine concentration. These parameters were varied symmetrically around the central point according to the 23 factorial design (Glucose 20.0, 40.0 and 60.0 g/L; Tiamine 0.002, 0.005 and 0.008mg/L; Asparagine 1.0, 2.0 and 3.0g/L). An estimate of pure experimental error was calculated from four replicates run corresponding to a central point of the complete factorial. The response recorded were chitin and chitosan yield. The flasks were incubated at 28°C, 150 rpm, during 72 hours. The mycelia were harvested, washed and submitted to lyophilization process. The process of extraction of chitin and chitosan involved deproteination with sodium hydroxide solution, separation of alkali-insoluble fraction, extraction of chitosan by Acetic acid. The degree of deacetylation for chitin and chitosan were determined by infrared spectroscopy. The data were analyzed for significance by the Student’s t-test and chi-square test, using the Statistic program, version 6.0 of Statsoft Inc., USA. The best yield of biomass was obtained in experimental condition 6. (glucose 60.0g/L, Tiamine 0.008 mg/L and asparagine 1.0g/L). On the other hand the best yiels of polysaccharides were obtained in experimental condition 4 (60.0g/L glucose, 0.003mg/L thiamine and 3.0g/L asparatine) for chitosan (96 mg/g) and in experimental condition central point (40.0g/L glucose, 0.005mg/L tiamine and 2.0g/L asparagine) for chitin (202mg/g). There was no statistical difference, 95% significance, between the parameters studied for chitin and chitosan production. The obtained results suggested that the carbon and nitrogen source of the culture medium influence the chitin and chitosan production.
https://doi.org/10.1142/9789814405041_0084
Bangoura A.O. et al. [1] studied the preparation of fibersol-2 by applying brewing yeast Saccharomyces Serevisiae for removing free glucose liberated during enzymatic hydrolysis of the pre-treated cornstarch (this method is called yeast application for desalting fibersol-2); followed by assessing the chelating capacity of this new product to calcium ions.
In the present work, 36 mice were fed within 3 days to study the physiological effect of fibesol-2 desalted by yeast and calcium chelated fibersol-2. The feed types were as follows; stock feed: 6.977 mg/g of calcium content; fibesol-2 desalted by yeast: 0.462 mg/g of calcium content; calcium chelated fibersol-2: 9.274 mg/g of calcium content; and CaCl2: 11.1mg/ml of calcium content.
The results indicated that there is statistically insignificant difference of the blood glucose levels of the two products as analyzed by Duncan’s test. Also the blood glucose levels of the two products are between the normal ranges (3.85-6.2mmol/L), which ranges is also specific for human. The test insulin content after feeding mice indicated that, the insulin secretion levels of mice fed with fibersol-2 desalted by yeast and calcium chelated fibersol-2, were also between the normal ranges (1.9-23mmol/L). These results indicated that fibersol-2 desalted by yeast, as well as calcium chelated fibersol-2 improved glucose tolerance and no delay of calcium absorption in the digestive tract.
The results in this study also indicated that faecal volume were increased for the mice fed with fibersol-2 desalted by yeast and calcium chelated fibersol-2, compared to the references groups. These results were also the same for the weights of the urine from mice fed with fibersol-2 desalted by yeast and calcium chelated fibersol-2, which were also increased compared to the other groups with the same feed consumption.
The consumption of fibersol-2 desalted by yeast and calcium chelated fibersol-2 are good ways to help the digestive system clean and healthy, to improve glucose tolerance and to control calcium deficiency disease.
https://doi.org/10.1142/9789814405041_0085
In this study we isolated and screened 58 thermophilic actinomycetes strains for proteolytic activity. The 11A strain originally isolated from a soil sample collected from Antarctic areas that showed highest proteolytic activity was chosen for further analyses. The accomplished observations on the microbial growth in continuous shake flasks confirmed the strain’s thermophilic nature and identified its maximal protease synthesis at 45°C for 48h. The pH profile for enzyme production was investigated as well. The observed pH range was from 6.5 to 8.5 and the optimal value for the maximal enzyme synthesis was determined at pH 8.0. The influence of different temperatures on the enzyme activity was observed for period of 2 days. The enzyme retained more than 90% from its initial activity during incubation at 50°C for 48h. It was also found that the enzyme is relatively stable up to 80°C. The influence of different concentrations of carbon and nitrogen nutrient sources on the level of enzyme production was also investigated.
https://doi.org/10.1142/9789814405041_0086
It has been determined inactivation kinetics of Eschericha Coli 433 from Spanish Type Culture Collection (CECT) by high hydrostatic pressure inoculated in nutrient broth (pH 7.4 ±0.2), for a range of pressures of 150, 175, 200 and 225 MPa with exposure times of 0 to 14 minutes, and 30°C. The survival curves were adjusted to three mathematical models: Weibull, Baranyi and Gompertz. The best goodness of fit was obtained for the Modified Gompertz Equation with values of R2 adj = 0990, and RMS = 0138. The validation of mathematical modeling was done through calculating accuracy and bias factor (Af and Bf), being the best M.Gompertz E. Finally, it was determined the secondary kinetic parameter (Z (P)) or constant resistance to pressure, for each model, specifically the value determined by the Gompertz model resulted in 125 MPa.
https://doi.org/10.1142/9789814405041_0087
Plasmid copy number (pcn) is a key parameter in studies on antibiotic resistance, recombinant protein production or plasmid biology. We have analysed a set of plasmids derivatives of F, P1ΔincA, pSC101, R1, p15A and pBR322 replicons in Escherichia coli.All of them harbour the GFPmut2 gene under the control of pBAD. We have made use of constant GFP expression in the presence of arabinose to quantify pcn by spectrofluorometry (pcn/mass) and flow cytometry (pcn/cell). Exponentially growing cultures at 30°C, 37°C and 41°C were analysed. Plasmid copy number showed a dependence on temperature incubation in a growth rate-dependent manner. Except for F and pBR322 derivatives, the faster the growth rate, the higher the pcn. GFP fluorescence quantification from cell cultures was a straightforward approach to pcn determination. Comparing to Southern method, pcn determinations by spectrofluorometry gave more precise determination than flow cytometry.
https://doi.org/10.1142/9789814405041_0088
Microbial secondary metabolites are low molecular mass products, not essential for growth of the producing cultures, but very important for human health. They include antibiotics, antitumor agents, cholesterol-lowering drugs, and others. Bacitracin is a polyenic antibiotic produced by bacteria of the Bacillus genus. Milk serum is a residue obtained by the production of cheese. Production of bacitracin by Bacillus licheniformis (UCP1010) was performed using a 23 factorial design, aiming to assess the influence of temperature and concentrations of glucose and milk serum. The production was detected by disk diffusion test using Micrococcus flavus as microorganism test. The results showed that the best production occurred at 37°C, at alkaline pH, after 72h of growth, with halos of 27mm in diameter, indicating that the tests based on the conditions of the central point showed best potential for production of bacitracin. Thus, the concentrations of milk serum at 40% (v/v) and 20g/L of glucose were more efficient for the production of the antibiotic.
https://doi.org/10.1142/9789814405041_0089
Solubilization, precipitation, sorption, and uptake of metal cations by microorganisms justifies the use of fungi in the removal of superficial radionuclide deposits from brickwork and (corroded) metal elements of dismantled nuclear power facilities and accidental spills on a dry way. The citrate and oxalate releasing ascomycete, Aspergillus niger, the oxalate producing brown-rot basidiomycete, Fomitopsis pinicola and several wood- and soil-inhabiting basidiomycetes were tested for their ability to acquire, and translocate uranium and to reduce the weight of metal plates by the expected production of carboxylic acids. Metals and plates of Portland cement were also exposed to solutions of carboxylic and mineral acids to substantiate the results. The nature of the watersoluble and -insoluble reaction products was not determined. The recalcitrant uranium was taken up and translocated through 100-mm long hyphal systems. In addition, all fungal mycelia were able to reduce the weight of the pure or alloyed metals, Fe > Zn > Cu, CuZn > AlMgSi > Cr significantly when added as plates to liquid and solid fungal substrates for 50 to 180 d. The dominating fungal carboxylic acids, malonic > citric, malic > oxalic in realistic solutions of 1 g L−1 were able to reduce the weight of Fe > Ni > Zn > Cu > Al disks upon the formation of soluble and insoluble compounds. The mineral acids, H2SO4 > HNO3 > HCl in solutions with a comparable initial pH transformed Fe > Ni >> Al primarily to insoluble precipitates. Plates of Portland cement increased their dry weight in the solutions of carboxylic acids apparently by the incorporation of the acids’ carbon whereas the mineral acids reduced the dry weight of the samples. Calcium was solubilized by all acids but oxalate. It is concluded that trace metals such as U spread in entire fungal networks which can thus serve as repositories of critical nuclides. In addition, fungal carboxylic acids dissolve (potentially contaminated and corroded) metal surface layers in the μm range by the formation of soluble and insoluble compounds most of the latter can be brushed off. Further tests comprise the placement of plastic-net stabilized lignocellulose mats overgrown with trace metal accumulator fungi on dry structured surfaces contaminated by critical nuclides and the subsequent ashing of the mats by air filtering. Respective in-situ tests with contaminated construction elements are inevitable to confirm economy and efficacy of microbial versus acid- and surfactant-based cleaning procedures.
https://doi.org/10.1142/9789814405041_0090
Cooling water is generally contained naturally occurring all living organisms and nutrients present in it are responsible for uncontrolled multiplication of the living organisms. Among them SRB are initiating the pitting on both stainless steel and mild steel metals by producing H2S & the formation of black sulphides (FeS) shows black shiny look.The spices Desulfomonas & Desulfobacillus are commonly found in recirculating system. SRB take part in the formation & stabilization of Biofilm along with Bacillus and Pseudomonas species. Thus they developed Microbial Induced Corrosion (MIC) on heat exchangers surfaces, which reduces the cross sectional area of heat exchangers thereby reducing efficiency of plant.
https://doi.org/10.1142/9789814405041_0091
Applications of ultrasound were starting from 1912 with the primary objective the detection of icebergs on prevention of maritime accidents. Algae, fish deaths and destruction were observed in the vicinity of sonar that equipped ships and submarines during the First World War.
The evolutions of research and studies with ultrasound have big advances following the discovery of piezoelectric transducers in science and technology. As an example we can mention its application in microsurgery, fatigue detection in aerospace mechanics, catalysis sonochemical, biotechnology and others.
The work presented here aims to demonstrate the application of ultrasonic in pulsed mode beams in biotechnology with the aim of improving the fermentation of a culture broth containing biological agents. In these experiments we used as ultrasound equipment and oscilator Sonics VCX-600 (20KHz), probe type wave guide. The experiments were conducted in a glass reactor of 200 mL of biomaterial containing cane juice and Saccharomyces cerevisiae in suspension. The parameters analyzed were related to the content Alcohlic (FID gas chromatography), and cell viability (Neubauer chamber), TRS (refractometry). Analysis of results showed that the total production exceeded in irradiated samples compared to normal fermentation (without ultrasound), suggesting additional advantage of ultrasound activation. Lastin Trials 1400 min, showed ethanol production systems 12% more than non-enabled systems. In this context alternatives for ethanol production, bio fuel and many other byproducts of the alcohol industries and chemicals could benefit from the use of ultrasound beams in this range of frequencies.
https://doi.org/10.1142/9789814405041_0092
Periodontal disease is an oral disease that has a high incidence worldwide, and it is considered the leading cause of tooth loss in adults. This condition is characterized by an infectious disease, painless and slowly progressive, being one of the main etiological agents Porphyrormonas gingivalis bacteria. This article analyzes the antibacterial activity of methanol extracts in different parts of the plant Azadirachta indica (A. Juss) planted in the northeastern region of Mexico, and currently used empirically in the development of toothpastes used in the people of this region. In some of the extracts tested were more active on P.gingivalis leaf, it shows more inhibition hales that tell us that the extracts of Neem afected the bacterial activiy. The data obtained from this analysis will be crucial to assess the feasibility and safety of its therapeutic use in humans.
https://doi.org/10.1142/9789814405041_0093
Biocides have an important role in hospital infection control. The widespread use of biocides may lead to microbial resistance, in particular cross-resistance to antibiotics. The aim of the present study is to determine the qacEΔ1 gene, which has been known as a determinant of resistance to quaternary ammonium compound (qac), by polymerase chain reaction (PCR) in clinical isolates of multi-drug resistant (MDR) gram negative bacteria. Also,quantitative süspansion test were performed for fenotypic susceptibility to an qac disinfectant in gene positive isolates. Specific primers were used to amplify a 300 bp fragment of qacEΔ1 gene. The results of the present study may contribute to distribution of qacEΔ1 gene in our hospital isolates.
https://doi.org/10.1142/9789814405041_0094
Antibacterial activity of alkaloids of two medicinal plants Fumaria bastardii and Fumaria capreolata was evaluated by two diffusion methods, wells method and disks method, against four bacterial stocks resistant to antibiotics isolated from infected patients in hospital. The tested strains are S.aureus S56, K. pneumoniae E47, P. aeruginosa 604 and E. coli. The contents of alkaloids were 2,42% and 1,17% in Fumaria bastardii and Fumaria capreolata respectively. Both alkaloid extracts showed a high antibacterial activity against the four strains tested. However P. aeruginosa was the least susceptible strain. Extract of F. bastardii was the most active one showing a higher activity excepted against P. aeruginosa which was most susceptible to F. capreolata extract. A synergy effect was observed between alkaloids of F. bastardii and the SXT on K. pneumonia and between alkaloids of F. capreolata and the SXT on P. aeruginosa 604.
https://doi.org/10.1142/9789814405041_0095
Biofilms containing antimicrobial agents are gaining importance as environmentally-friendly food packaging systems to extend product shelf life. Biofilms based on calcium caseinate, plasticized with three different concentrations of glycerol (15, 25 and 35 wt%) and with 10 wt% of carvacrol, were prepared by solvent casting. Their biodegradation was tested under composting conditions by using Fourier transform infrared spectroscopy, while barrier properties were evaluated by determining oxygen transmission rate. Finally, antimicrobial effectiveness against Escherichia coli and Staphylococcus aureus was tested by using the agar diffusion method. Calcium caseinate based biofilms showed rapid degradation under composting conditions and excellent oxygen barrier properties in all cases. Formulations with carvacrol exhibited clear inhibitory effects against both bacteria tested. These results showed the potential of calcium caseinate as a matrix for bioactive packaging systems, leading to a possible increase in foodstuff shelf life by reducing oxidative degradation and decreasing microbial contamination.
https://doi.org/10.1142/9789814405041_0096
Strain PT708 was isolated from cave soil at Pha Tup Cave Forest Park, Nan Province, Thailand. Phylogenetic analysis indicated that it belongs to the genus Nonomuraea, with a relatively high similarity value (98.28%) to the 16S rRNA gene sequence to Nonomuraea roseola AJ278221 and Nonomuraea dietziae AJ278220. However, its unique morphology, forming a single spore at the end of branched mycelium, is different with those species of the genus Nonomuraea. Consequently, we propose that the strain should be assigned to a new species in this genus. Strain PT708 showed ability to produce antimicrobial compounds against Bacillus cereus, methicillin-resistant Staphylococcus aureus (MRSA) and Paenibacillus larvae when it was grown in AMHU-5 medium. MRSA and B. cereus are the most susceptible strains, with equal MIC values of 80 μg/mL followed by P. larvae with MIC value of 175 μg/mL. Moreover, a crude extract from this strain showed anticancer activities against human small cell lung cancer (NCI-H187) and human oral cavity cancer (KB) with IC50 values of 3.48 and 16.11 μg/mL, respectively, but no inhibition was observed for human breast cancer (MCF7) with concentration up to 50 μg/mL.
https://doi.org/10.1142/9789814405041_0097
The aim of this study was to evaluate the susceptibility to antibiotics and quaternary ammonium disinfectants of Acinetobacter baumannii strains isolated from patients with nosocomial infections and the environment of the ICU and Neonatal Service (NS) at the Caracas University Hospital. Resistance to 15 antibiotics was determined. To evaluate the disinfectant resistance phenotypes tests recommended by the AOAC were used. ERIC-PCR and REP-PCR were used for genotyping. We analyzed 74 A. baumannii, 14 and 1 from ICU and NS patients, respectively; and 42 and 17 from its corresponding environments. 44.6% of the isolates showed resistance to at least 7 antibiotics. 54% of isolates tested exhibited the resistance phenotypes to the quaternary ammonium hospital disinfectant evaluated. 73% of the isolates from patients were closely related clones, 28.8% of the environmental isolates were grouped in 7 indistinguishable clones groups. The multiple antibiotic and disinfectant resistance profiles and the presence of related bacterial clones demonstrate the need for antibiotic usage surveillance and alternative cleaning methods in this hospital.
https://doi.org/10.1142/9789814405041_0098
Medical plants synthesize a vast array of secondary metabolites that are important for human life. For medical purpose, antimicrobial activity of substances derived from plant extracts has been recognized since antique years. Antibacterial activity of seed extracts of Pimpinella anisum (Aniseeds) was evaluated against some pathogenic bacterial strains (Streptococcus pyogene, Psedomonas aeruginosa, Klebseilla pneumoniae and Proteus vulgaris) on 6 different concentrations which are 1, 5, 10, 20, 50 and 100 mg/ml for methanol and aqueous extract. Aqueous extract of seed was found to be more sensitive and showed highest antibacterial activity against tested bacteria. It is exhibited varying level of antibacterial activity (20 − 100 mg/ml) on Streptococcus pyogene, Psedomonas aeruginosa, Klebseilla pneumoniae and Proteus vulgaris. Methanol extract showed a resistant to Klebseilla pneumonia and Proteus vulgaris. Both extract of Pimpinella anisum showed significant antibacterial activity against Streptococcus pyogenes and Pseudomonas aeruginosa with a greater inhibition zone (≥15mm) on 20, 50 and 100mg/ml. Mann-Whitney analysis showed there are no significant differences (p ≥ 0.05) between methanol and aqueous extract. Based on Kruskal Wallis analysis, both aqueous and methanol extract of aniseed showed a significantly differences (p ≤ 0.01) inhibition on bacteria gram positive (Streptococcus pyogenes) compared to bacteria gram negative (Psedomonas aeruginosa, Klebseilla pneumoniae and Proteus vulgaris). The sensitivity of test bacteria varied with the species, strains and concentration of extract applied. Spearman’s analysis was done and it showed that there is positive correlation between concentrations and diameter of inhibition zone of bacteria. The higher concentration used will increased the diameter of inhibition zone.
https://doi.org/10.1142/9789814405041_0099
The main goal of this study was to identify Porphyromonas and Prevotella species from periodontal pockets of Portuguese adults suffering from periodontitis infections. Results showed that Prevotella intermedia represented 44% and Porphyromonas gingivalis 20% of total isolates. The remaining 36% strains belonged to other black pigmented species.
The isolated bacterial species were further tested for their β-lactamase production. Results from the disk diffusion method were confirmed by nitrocefim disks and showed no β-lactamase production by Prevotella intermedia and Porphyromonas gingivalis strains. Only 2% of other Prevotella sp. showed β-lactamase production.
Moreover, we studied the susceptibility of these bacterial species to five antibiotics commonly prescribed as treatment or prophylaxis in odontology in Portugal. The isolated strains showed susceptibility to all tested antibiotics.
https://doi.org/10.1142/9789814405041_0100
The direct connection between consumption of Arcobacter contaminated water and human diseases has not been established yet, although it is likely that water may play an important role in the Arcobacter transmission to humans. Fluoroquinolones are potential drugs to treat infections due to these organisms. However, there is evidence of increasing resistance to these antimicrobial agents. This resistance may occur due mutations in a quinolone resistance-determining region (QRDR) of the gyrA gene. In this study, Arcobacter susceptibility to fluoroquinolones was determined by disc diffusion tests and E-test strips. In addition, to elucidate the mechanism of quinolone resistance, we carried out sequence determination and analysis of the QRDR of their gyrA gene. Among the 60 isolates tested, 14 were considered to be resistant to quinolones by disc diffusion tests and E-test strips. The sequencing of the PCR products revealed a mutation in position 254 of the gyrA gene in the 14 resistant A. butzleri isolates. This C-254 to T mutation could be the cause of quinolone resistance as this change was absent in all the susceptible isolates.
https://doi.org/10.1142/9789814405041_0101
There is an increasing awareness worldwide with the high morbidity and mortality rates among different groups of human patients and animals caused by fungal infections, especially from resistant strains of Candida spp. Epidemiological studies have identified risk factors associated with antifungal drug resistance, like haematological malignancies, prolonged neutropenia or immune depression. Rapid and sensitive fungal identification and antifungal susceptibility testing are essential to guide physicians in selecting more appropriated antifungal therapies. We present here an overall strategy for detection and identification of Candida spp. by the one-enzyme restriction fragment length polymorphism (RFLP) PCR-based technique and a simple and standardized diffusion-disk method for sensitivity testing. This combined method achieved high sensitivity and specificity of detection, allied to rapid, simple and sensitive drug susceptibility assessment among Portuguese and Tunisian clinical isolates.
https://doi.org/10.1142/9789814405041_0102
The crystal morphology and Cry protein composition of twelve Cuban Bacillus thuringiensis (Bt) strains were analyzed. Their in vitro biological activities were evaluated against Spodoptera frugiperda, Anticarsia gemmatalis and eggs of the nematode Meloidogyne incognita. The scanning electron micrographies as well as the morphology, size and number of the inclusions showed variations amongst the different strains, as expected. The Cry protein SDS-PAGE profile showed proteins of 130 kDa and 70 kDa. The bioassays showed two Bt strains highly active against S. frugiperda and A. gemmatalis, and six strains interrupted the development of nematode egg´ mass. There were different behaviors regarding nematode infectivity but all of them resulted in nematostatic and disorientation effects under the experimental conditions. Based on the results obtained the two most virulent strains will be further studied for mass production and formulation as a biopesticide.
https://doi.org/10.1142/9789814405041_0103
The prevalence of Staphylococcus aureus carriage among healthy children from four kindergartens located in the North of Portugal and antibiotic resistance of the isolates were evaluated. Nasal swabs were collected from 296 healthy children aged 3 to 6 year. 144 were carriers of S. aureus; 15% of the strains were multidrug resistant. Resistance to gentamicin, chloramphenicol, rifampicin, oxacillin, nitrofurantoin, tetracycline, erythromycin, ampicillin and penicillin were determined to be 1.5, 2.2, 2.2, 9.7, 19, 34.1, 73.3, 84.4 and 91.1%, respectively. All the strains were sensitive to vancomycin. Our study reveals a high prevalence of healthy children carrying S. aureus (49%), including MRSA (9%), in the nasal cavity.
https://doi.org/10.1142/9789814405041_0104
Haemophilus influenzae type b (Hib) is a human pathogenic bacterium causing meningitides mainly in children less than 2 years old. Capsular polysaccharide is the main factor of virulence and is used as antigen in the Hib vaccine. In this study a trustful protocol for removing the interferences from fermented broth based on the interaction of polysaccharide-surfactant was established. Interferences from the culture medium were removed by using dialysis, fractionation by ethanol and cetyltrimethylammonium bromide (CTAB), a cationic surfactant. CTAB protocols were able to eliminate interference better than dialysis or ethanol precipitation, giving low false positive values and allowing satisfactory molecular weight distribution analysis.
https://doi.org/10.1142/9789814405041_0105
The purpose of this study was to determine whether the precautionary measures used in the Faculty of Dentistry, University of Nuevo Leon, are adequate to prevent infection with Mycobacterium tuberculosis, taking as evidence two groups: one of 92 students of 2 °. Half have not seen patients and another group of 108 students in 9 th. and 10 °. Semesters that have served patients in different clinics of the institution. Research were conducted in two laboratory tests, the Mantoux test by inoculating 0.1 ml of PPD (purified protein derivative) to read 48 hours later, taking as positive for the one with induration of 10mm or more prior contact means with the bacillus and obtaining from them 5 mL of peripheral venous blood to perform the ELISA test for detection of latent TB blood test that analyzes the presence of IgM and IgG antibodies against extracellular proteins of Mycobacterium tuberculosis (Dr. C. Alma Yolanda Arce Mendoza). Among the groups studied, the 2 °. Semester (new entry) were found to have greater contact with M. tuberculosis than 9 °. and 10 °. Semesters when analyzing the results of the group F6, F7 and F8 where there are more students tested positive test, this equates to 29.3% and indicates infection is present. Since only two students from one hundred and eight total semesters analyzed above were positive for IgM, this equates to a rate of 1.8%. In conclusion, newly admitted students who tested positive to the tests, and had previous contact in your environment, and that means immune resistance to tuberculosis infection. Furthermore, the absence of a positive IgM test increased in the group of students from 9 th. and 10 °. Semesters, indicates that there is no danger of infection during their professional development.
https://doi.org/10.1142/9789814405041_0106
Orthodontics as a science can not be isolated from the dental and cultural evolution of the world. The application components can cause alterations in microbial flora due to reduced pH and increased retention areas for microorganisms.
Objective. Determined by multiplex PCR, the presence of Streptococcus mutans, Porphyromonas gingivalis, Streptococcus intermedius and Streptococcus sobrinus in patients with orthodontic treatment techniques in the MBT and Alexander Orthodontics Clinic UAS.
Materials and Methods. Were token 80 patients of both sexes attending the Clinic of Orthodontics and Orthopedics at the UAS of between 12 and 25 years old with fixed appliance orthodontic techniques Alexander (0.18) and MBT (3M), with a minimum of 3 months placing the brackets, all samples were applied Multiplex PCR.
Results. In 41 patients with brackets Alexander, Streptococcus intermedius, 8 (19.5%) compared with 39 patients with MBT brackets Porphyromonas gingivalis in brackets Alexander 5 (12.2%) cases versus 1 (2.6%) case in MBT Brackets, Streptococcus mutans was (p = .738) in brackets Alexander 6 (14.6%) versus 4 (10.3%) MBT. Streptococcus Sobrinus was (p =. 433) with Alexander Brackets 5 (12.2%) and 2 (5.1%) with MBT brackets.
Conclusion. Is to identify microorganisms associated with dental caries and periodontal disease in patients with brackets attached (Alexander) and twin brackets (MBT). The increased presence of microorganisms in number and species was attached (Alexander) compared with twin brackets (MBT). There were no organisms analyzed in this study for age, sex and design of brackets.
https://doi.org/10.1142/9789814405041_0107
Genus Mentha is a well-known species that has a variety of biological properties and abundantly available throughout temperate regions. Member of Mentha genus have been used as a folk remedy for treatment of nausea, ulcerative colitis and liver complaints due to its anti-inflammatory, carminative, stimulant and antioxidant activities. This study was designed to evaluate mutagenic and anti-mutagenic activities of rosmarinic acid (RA), a phenolic compound isolated from Mentha longifolia ssp. longifolia. The possible anti-mutagenic potential of RA was examined against mutagens ethyl methanesulfonate (EMS) and acridine (AC) in Saccharomyces cerevisiae RS112. According to our findings, only one concentration of RA showed a mutagenic effect in the highest concentrations used. The lower concentrations of RA significantly inhibited EMS and AC-induced mutations. The highest inhibition rates in yeast DEL assay ranged from 10 % (4 μM/ml concentration in EMS-induced DEL events) to 63.3 % (2μM/ml concentration in AC-induced DEL events). This study suggests that the phenolic compound, RA can possess mutagenic effect in high doses. While this plant is used commonly, the amount of phenolics in food supplementation has to be well adjusted for their efficient dose and safety. Moreover, the antimutagenic/anticarcinogenic properties of RA observed in this study are of great pharmacological importance, and might be beneficial for phytotherapeutic drug discovery and development.
https://doi.org/10.1142/9789814405041_0108
In the present study, the chemical composition of the essential oil (EO) of Mentha longifolia L. Hudson ssp. longifolia (ML) and the antibacterial activity of the EO against phtopathogenic bacteria were determined. The EO of ML that grown in Eastern Anatolia was isolated by the hydrodistillation method and analyzed by GC-MS. According to GC analysis of the chemical composition of the EO of ML, it consisted of 12 identified components. Major components of the oil were cis-Piperitone epoxide (26.52%-GC), Piperitenone oxide (26.40%) and Pulegone (15.66%). The antibacterial activity of the EO was also tested against 20 phtopathogenic bacteria. In general, the oil had antibacterial activity at a wide spectrum on the growth of phtopathogenic bacteria. In conclusion, the results revealed that the EO of ML have significant antibacterial activity, and the findings of the present study are valuable for further investigations focusing on controlling plant pathogenic bacteria that cause crop loss.
https://doi.org/10.1142/9789814405041_0109
The bioactivity and purification of compounds produced by endophytic S. tubercidicus isolated from Solanum lycocarpum St. Hill, a typical Brazilian tropical savannah tree, was achieved. S. tubercidicus presented bioactivity against S. aureus (ATCC 29213), E. coli (ATCC 25922) and C. albicans (ATCC 10231) with 35 mm, 40 mm, and 19 mm antibiosis hales, respectively, but failed to inhibit P. aeruginosa (ATCC 27853). The growing kinetics was evaluated during 21 days and the major quantification detection was 7.88 log CFU.mL−1, observed at the second day of incubation. The fresh crude extract showed a maximum antimicrobial potential of 200 AU.mL−1 against E. coli and S. aureus. Separation of crude extract of S. tubercidicus on Sephadex LH-20 gel methanol revealed two compounds presenting bioactivity against S. aureus and E. coli. Analysis under UV illumination showed three distinct compounds, two of them were less polar (254 nm) and one was more polar (365 nm). All these findings can contribute to the characterization of new and useful antimicrobial substances with various applications.
https://doi.org/10.1142/9789814405041_0110
Urokinase is a serine protease that converts plasminogen into plasmin and initiates the process of fibrinolysis. In the event of stroke and myocardial infarction, urokinase is one of the preferred drugs for clinical intervention as it has no known immunological reaction and few reported incidences of hemorrhagic complications. A clinical formulation of urokinase contains the active protein of molecular weight ranging from 50 to 80 kDa. Commercially, urokinase is produced primarily by mammalian cell culture. Since mammalian cells have a slower growth rate compared to microbes, maximizing productivity while meeting quality and regulatory requirements presents a formidable challenge. This work attempts to address these issues in part by identifying metabolic states that associated with high production rates of urokinase and correlating these with operating conditions. Human fibrosarcoma HT1080 cells were employed for the production of urokinase. The reactions of the metabolic pathway were elucidated and the biosynthetic pathway was created. Flux map distributions for various metabolic states were calculated using the data obtained from bioreactor studies. The optimal flux distributions corresponding to both cell growth and urokinase synthesis were determined. Two distinct physiological states were identified and examined to understand metabolic variations during urokinase production.
https://doi.org/10.1142/9789814405041_0111
The activity of the dermaseptine S4 derivative S4(1-16)M4K against 6h-old Pseudomonas fluorescens biofilms has been assessed by using the Attenuated Total Reflectance - Fourier Transform InfraRed (ATR-FTIR) spectroscopy. The ATR-FTIR fingerprints of bacteria were monitored in situ and in real time during 24-hour treatment with the antimicrobial peptide (AMP) by using an ATR-FTIR flow cell. After antimicrobial peptide treatment biofilms were analyzed by epifluorescence microscopy using the live/dead bacterial viability kit in order to determine bacterial surface coverage and the viability of biofilm cells. After exposure to the peptide, major and rapid changes or in contrast no change over time were observed in ATR-FTIR fingerprints of biomolecules revealing major biochemical and physiological changes, adsorption peptides on the bacterial membranes, bacterial detachment, bacterial regrowth or in contrast inhibition of biofilm growth. This study shows that the ATR-FTIR technique can be a valuable tool for in situ monitoring the activity of AMPs against sessile bacteria.
https://doi.org/10.1142/9789814405041_0112
The objective of this work was to evaluate the synergism effect of citric acid, lemon oil, lime oil and nisin as sanitizer to inhibit the growth of Escherichia coli, “in vitro”, using statistical design (23 factorial designs with three central points). The experiment was carried out, varying the concentrations of citric acid (% w/v, 0; 0.5; 1.0), lime oil (% v/v, 0; 1.0; 2.0) and nisin (IU/mL, 0; 50; 100), using nutrient broth as media. Escherichia coli was inoculated into 11 flasks (106 CFU/mL), which were incubated at 37°C during 24 h. The interaction between lime and lemon oil was also studied. The results showed that after 1h, only citric acid and lime oil had significant effects on inhibition growth of the E. coli as well their interaction (p<0.05). When the factors were combined, the reduction was 100%. No combined effect on combating bacteria growth was observed between lime and lemon oils in the range studied.
https://doi.org/10.1142/9789814405041_0113
Community acquired methicillin Staphylococcus aureus (CA-MRSA) was first reported in 1981, infecting people without risk factors. These strains harbor the Staphylococcal Cassette Chromosome mec (SCCmec) type IV, which contains the mecA gene codifying for methicillin resistance. CA-MRSA strains usually carry PVL (Panton-Valentine Leukocidin), a virulence factor responsible for tissue invasion, causing systemic infections and leading to serious complications. The aims of this work were to detect the mecA gene, SCCmec characterization and to detect the PVL gene of the S. aureus strains isolated from patients diagnosed with skin and soft tissue infections attending the Dermatology Service, of the Botucatu Medical School, Brazil. Among 127 collected samples, 66 (51.9%) were S. aureus and, from these, 7 (10.6%) harbored mecA gene, 3 (42%) with cassette type IV, and none of these samples carried the PVL gene, but it was detected in 10 (15.1%) samples of S. aureus methicillin sensitive (MSSA). Our study suggests the S. aureus strains that harbor PVL gene and MRSA are present in the community as important pathogens.
https://doi.org/10.1142/9789814405041_0114
Antibiotic resistance is a reemerging problem facing health care settings globally. Among the possible routes to offset this challenge is to try and find out means of combating resistance and pathogenecity by reducing the virulence rather than growth inhibition. One of the most promising proposals is inhibiting or modifying quorum sensing systems in bacteria. This study focuses on screening epiphytic bacteria from wild berries for quorum sensing inhibitors(QSI). For this purpose 600 bacterial isolates were isolated and screened for quorum sensing substances using the Chromobacterium violaceum monitor strain system. Eleven isolates showed clear QSI activity against C.violaceum both on agar plates and when culture supernatant was tested using agar diffusion method. all positive isolates were gram-positive aerobic rods.Opimization of production of the QSI materials by some isolates is underway together with partial identification of these materials.
https://doi.org/10.1142/9789814405041_0115
In the last two decades, there has been an increase in incidence of invasive pulmonary aspergillosis (IPA), resulting in extremely high morbidity and mortality rates, as a result of the intense use of chemotherapic and immunosuppressive agents, especially in immunocompromised patients and, among these, hemato-oncologic and bone marrow transplanted patients. Such fungal infections are caused by some species of the genus Aspergillus, where A. fumigatus has been the most frequent species isolated from human infections. A key factor for the increased incidence of IPA is the inability to establish early definitive diagnosis aimed to initiate prompt and specific antifungal therapy, which would ensure favorable prognosis for these patients. In this work, 37 blood samples were studied, mostly with clinical diagnosis for acute myeloid leukemia. The main goal of this study was to compare a standard immunological test (detection of galactomannan antigen) with the molecular nested-PCR test, in order to determine which one offers more sensitive and specific outcomes.
https://doi.org/10.1142/9789814405041_0116
Periodontal disease has been associated with a poor dental care, which promotes the accumulation of bacteria and the development of diseases of the mouth. It is well known that our oral cavity could to harbor more than five hundred different microorganisms type, resulting several microbial interactions, such as induction of some virulence factors, toxin-gene expression, and quorum sensing response. Among this bacterium we can find to Porphyromonas gingivalis and Streptococcus intermedius, which belong to the normal oral habitants. However, the amount of these bacterial could be the difference between disease or health. Our hypothesis is that when S. intermedius cell number is higher, it might trigger the expression of some virulence genes in P. gingivalis. The objective of the present work is to evaluate expression of several virulence genes from P. gingivalis in a mixed culture with S.intermedius using qPCR and heterologous microarrays.
https://doi.org/10.1142/9789814405041_0117
Thapsia garganica is an endemic plant which grows spontaneously in Mediterranean basin. It is used by Algerian population for some cases of rhumatism.
In this study we tested the antibacterial activity of acetonic extracts of the leaves and roots of Thapsia garganica on four bacterial strains Escherichia coli, Pseudomonas aeruginosa, Listeria innocua, Staphylococcus aureus for this four concentrations of the extracts were prepared 100mg/ml, 50mg/ml, 25mg/ml and 12.5mg/ml.
Results indicated that acetonic extracts of the leaves have the best antibacterial activity with inhibition zones varying from 6 to 32 mm. Extracts at 100mg/ml were better than the other dilutions. The Gram negative becteria were more sensitive than the Gram positive ones.
MIC results indicated that all the strains have a minimum inhibition concentration higher than 4mg/ml except for Staphylococcus aureus wich showed a MIC of 3.1mg/ml.
https://doi.org/10.1142/9789814405041_0118
Antibiotic resistance in bacteria is one of the emerging health related problem in the world Nowadays. Medicinal plants ate valuable natural sources effective against infectious agents. In this study, methanolic extracts of four marine algae of Algeria coast were investigated for antibiotical and antifungal activities against respectively six pathogenixc bacteria (Bacillus subtilis, Listeria inocua, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa), and three specis of fungi (Candida albicans, Mucor ramanianus, Aspergillus niger). All algae extracts showed antibacterial activity against four of the six pathogenic bacteria tested, with MIC value (minimum inhibitory concentration) ranged between 0.25-3mg/ml. Extracts of Rhodomela confervoïdes exhibited highest activity against Bacillus subtilis (24mm), Cystoseira tamariscifolia exhibited the highest activity against Listeria innocua (19.67mm). All the extracts exhibited antifungal activity. The highest inhibiting effect was noted for Rhodomella confervoïdes and Padina pavonica againts respectively Candida albicans and Mucor ramanianus for the first one. Aspergillus niger showed resistance against the majority of methanolic extracts.
https://doi.org/10.1142/9789814405041_0119
Oral Streptococci especially Streptococcus mutans are the major cause of dental caries and periodontal diseases. Going along with the increasing antibiotic resistance of bacteria and also biofilm forming bacteria, new methods for decreasing of oral cavity pathogens must be investigated. The aim of this study was to determine the effect of Lactobacillus fermentum ATCC9338, Lactobacillus acidophilus DSM 20079 and Lactobacillus rhamnosus ATCC 7469 as probiotic strains on the adhesion of oral streptococci as the pioneer strains of biofilm formation to the tooth surfaces.
S.mutans ATCC35668 and other oral streptococci isolated from dental plaque were studied. The ability of biofilm formation was investigated with colorimetric method and the strongest isolates were selected. Then the effect of probiotic strains on the adhesion of streptococci isolates were determined in polystyrene microtiter plate simultaneously (m1) and 30 minutes before streptococci entrance to the system (m2).
The results showed that in the presence of probiotic strains the streptococcal adhesion, then it’s biofilm formation, were reduced. The highest adherence reduction of mutans streptococci (31.44%) and non mutans streptococci (23.52%) were related to the presence of L. acidophilus and L. fermentum, respectively. The adherence reduction of streptococci was significantly stronger if the probiotic strain inoculated to the system before the oral bacteria. The effective pattern of probiotic strains on the adherence of mutans and non mutans Streptococci were as follows:
On mutans Streptococci: L. acidophilus > L. rhamnosus > L. fermentum
On non mutans Streptococci: L. fermentum > L. rhamnosus > L. acidophilus
It can be concluded that Adhesion reduction is likely due to bacterial interactions and colonization of adhesion sites with probiotic strain before the presence of streptococci. Adhesion reduction can be an effective way on decreasing dental plaque formation and also the cariogenic potential of oral Streptococci.
https://doi.org/10.1142/9789814405041_0120
Epidemiological studies have shown that enteropathogenic (EPEC) and enterotoxigenic (ETEC) Escherichia coli are the most frequent pathogenic groups found in Latin America, including Mexico. A simultaneous PCR test for ETEC and EPEC pathotypes was designed, which was based on the genes for effacing intimin and bundleforming pilus for EPEC pathotypes and on the heat-stable and heat-labile enterotoxin genes for ETEC pathotypes. The equivalent of ten genomic copies of EPEC pathotypes and one of ETEC pathotypes were specifically detected in DNA from the reference strains. In crude DNA extracts, EPEC strains were detected in one pathogenic bacterium colony among forty-five faecal isolates from patients with gastrointestinal infections in the state of Guanajuato, Mexico. Furthermore, two pathogenic ETEC strains were identified from the urine of patients with urinary infections.
https://doi.org/10.1142/9789814405041_0121
Rhodotorula rubra (RR) was cultured in salt synthetic medium with glucose as substrate. The reduced-minusoxidized difference absorption spectrum of cultured RR showed absorption bands due to cytochrome c oxidase at 601 nm, two cytochromes b with maxima at 560 and 564 nm, cytochrome c1 at 554 nm and cytochrome c at 548 nm. Antimycin A (AA)-treated cells showed only the absorption bands due to cytochromes c and c1 and cytochrome c oxidase. Addition of cyanide (KCN) (1 to 3 mM) or AA (8 to 25 μM) to RR enhanced cell respiration up to, respectively, 200% and 140% of the control value. Respiration enhancement induced by KCN and AA was inhibited by 8.2 mM salicylhydroxamic acid. Thus RR exhibited a typical eukaryotic respiratory chain and also a cyanide-insensitive respiration. RR colony growth was totally inhibited by 100 μg/ml cycloheximide, 50 μg/ml amphotericin B, or 3 μg/ml nystatin. Thin section electron microscopy showed that RR cells were oval or round, dividing by budding; distribution of cytoplasmic organelles was also described.
https://doi.org/10.1142/9789814405041_0122
Xanthophyllomyces dendrorhous synthesizes astaxanthin as the most representative xanthophyll derivative. This compound displays antioxidant properties and its production has been stimulated via reactive oxygen species (ROS). Detailed mechanisms for carotenogenesis in X. dendrorhous have not been elucidated. Carotenoid production was stimulated with H2O2 in X. dendrorhous wild type (Wt), mutants R4 (red, astaxanthin hyperproducer); W10 (white, accumulates phytoene); Y21 (yellow, accumulates β-carotene) and P26 (pink, accumulates monocyclic carotenoids), to identify important biosynthetic steps in this microorganism.
Addition of H2O2 prolonged the lag phase in all strains but reached similar growth at the stationary phase as that observed for their own control culture. The addition of H2O2 increased the carotenoid contents in 16 % for Wt and R4, 60 % in W10 and Y21 mutants, while in P26 this parameter remained constant. The results reported herein suggest that carotenogenesis induction by H2O2 may occur before the β-carotene step formation and its oxygenation is a limiting step in the astaxanthin formation pathway in X. dendrorhous.
https://doi.org/10.1142/9789814405041_0123
The new Saccharomyces cerevisiae killer toxin (Klus) killed all the previously known S. cerevisiae killer strains, in addition to other yeast species. The Klus phenotype is encoded by a medium-size dsRNA virus, ScV-Mlus, whose genome size ranged from 2.1 to 2.3 kb. Its genome structure is similar to those of M1, M2, or M28 dsRNAs with a 5’ terminal coding region followed by two internal A-rich sequences and a 3’ terminal region without coding capacity. Mlus positive strands carry cis acting signals at their 5’ and 3’ termini for transcription and replication similar to those of killer viruses. The ORF at the 5’ portion codes for a putative preprotoxin with an N-terminal secretion signal, potential Kex2p/Kexlp processing sites and N-glycosylation sites. No sequence homology was found either between the Mlus dsRNA and M1, M2, or M28 dsRNAs, or between Klus and K1, K2, or K28 toxins. The Klus amino acid sequence showed a significant degree of conservation with the host chromosomally-encoded ORF YFR020W of unknown function.
https://doi.org/10.1142/9789814405041_0124
Marinobacter hydrocarbonoclasticus was shown to have a high tolerance to copper sulphate. A minimum inhibitory concentration of 1.6 mM was determined, thus classifying Marinobacter hydrocarbonoclasticus as copper resistant. A proteomic approach based on two-dimensional gel electrophoresis provided a preliminary analysis over the differential protein expression induced by 1 mM of copper in Marinobacter hydrocarbonoclasticus. The copper stress led to a global change in the proteomic profile of the periplasmic fraction of this bacterium, involving modulation of the expression of 53 out of the close to 500 proteins detected, when compared with control growths with trace copper concentration.
https://doi.org/10.1142/9789814405041_0125
Among the four types of Saccharomyces killer yeasts already described (K1, K2, K28, and Klus), we found K2 and Klus killer yeasts in south-western Spain. The K2 yeasts were found in all the wine producing sub-areas during all the vintages analyzed, while the Klus yeasts were found in the warmest locations and mostly in the warmest vintages. The killer yeasts were present in most spontaneous fermentations. Most were K2 with Klus being the minority. The proportion of killer yeasts increased during fermentation, while the proportion of sensitive yeasts decreased. The fermentation speed, malic acid, ethanol yield, and wine organoleptic quality decreased in those fermentations where the killer yeasts replaced at least 15% of a dominant population of sensitive yeasts.
https://doi.org/10.1142/9789814405041_0126
The increasing search for ethanol fuel in order to reduce the dependence and to promote the substitution of fossil fuels will contribute to higher accumulation of sugarcane bagasse in the environment. This biomass that in Brazil is a co-product of the sugar-alcohol mills, although it has been used for the generation of energy in the sugar and alcohol production, can also be used as alternative for obtainment of xylitol, contributing to bring economical advantages for sugar-alcohol mills. The diluted acid hydrolysis has been commonly used in the researches for the obtainment of rich-xylose hemicellulosic hydrolysates. However, in this bioprocess there is also the release/formation of toxic compounds to the microorganisms, inhibitors of enzymatic activities like phenolics, organic acids, furfural, hidroxymethilfurfural, besides metallic ions. In this work it was evaluated the fermentative performance of C. guilliermondii FTI 20037 grown in hemicellulosic sugarcane bagasse hydrolysate detoxified with activated charcoal or vegetal polymer. Both promoted removal of toxic compounds of the hydrolysate, but activated charcoal resulted in the higher xylose consumption and higher xylitol production. These results indicate that additional research is required to achieve efficient removal of toxic compounds and to improve the xylose to xylitol bioconversion by C. guilliermondii.
https://doi.org/10.1142/9789814405041_0127
The plant pathogen Erwinia amylovora is responsible for fire blight disease, causing serious losses in pome fruitgrowing areas around the world. Difficulties in controlling fire blight have been related to the survival abilities of this pathogen in nature under different environmental conditions. One such survival strategy is the adoption of the viable but nonculturable (VBNC) state, where the cells remain viable but unable to grow on routine solid media. Because loss of culturability by VBNC cells has been related to oxidative stress, we have studied the expression of selected oxidative stress-related genes (katA, katG, and oxyR) in E. amylovora cells exposed to VBNC-inducing conditions. Gene expression was determined by reverse transcriptase polymerase chain reaction (RT-PCR), using the 16S rRNA gene as control. Initial results have shown down regulation of katA, katG and oxyR genes during the entry of E. amylovora cells into the VBNC state. However, the expression of the housekeeping 16S rRNA gene was maintained during entry and within the VBNC state.
https://doi.org/10.1142/9789814405041_0128
The aim of this work was to characterize the cellular stress, the production of reactive oxygen species (ROS), the liberation of nitric oxide (NO) and the enzymatic activity of superoxide dismutase (SOD), in the two bacterial species Staphylococcus aureus and Escherichia coli, which have both been associated with the formation of biofilms. We studied the influence of a different range of culture conditions (sugar, osmotic stress and reduction conditions). The extracellular production of ROS was evaluated by the reduction of nitro blue tetrazolium (NBT), the NO production was detected as nitrite using the Griess reagent and SOD activity being assayed using the inhibition of NBT. We observed that ROS, RNI and their downstream derivatives played important roles in biofilm development. This suggests that cellular stress affected the biofilms grown under different conditions. Our results suggest that biofilm formation was influenced by the different conditions, with a close relation seen between cellular stress (ROS and NO) and biofilm formation. Under favourable culture conditions for biofilm formation, the polysaccharide matrix was increased because the sessile cells were present at lower cellular stresses. The decrease in the extracellular matrix observed under unfavorable conditions for increasing the cellular stress, caused radical oxidizers to accummulate in an extracellular medium and thereby affects the matrix. In conclusion, we suggest that biofilm formations in a variety of environmental conditions are influenced by cellular stress. An improved knowledge of ROS, RNI and enzymatic pathway regulation may help to clarify the relevance of biofilm formation, and new advances in this aspect could also be of great value in the development of better preventive and therapeutic measures.
https://doi.org/10.1142/9789814405041_0129
Inorganic polyphosphate is a polymer constituted by repeat units of orthophosphates residues linked by highenergy phosphoanhydride bonds, which is ubiquitous in nature and have been considered an alternative energetic source. In this work was investigated the enzymatic activity of acid and alkaline phosphatases in ten strains of Cunninghamella elegans, a filamentous fungi belong to Zigomycetes. Assays were performed in agreement to a factorial arrangement with two levels (22) without central point, where glucose concentrations in the medium and growth temperature were the independents variables and inorganic polyphosphate accumulation and enzymatic activity were the variables response. Results showed enzymatic activities for all tested samples. Highest activity for two enzymes was demonstrated by C. elegans (UCP 542), which were 0,59 U.I/g of biomass to acid phosphatase and 0,34 U.I to alkaline. PolyP accumulation hasn’t influenced by phosphatases activity.
https://doi.org/10.1142/9789814405041_0130
Yeast S. cerevisiae sometimes inhabit in the environment, acidity of which is connected with significant L-malate concentrations. For example, such situation develops during manufacture of dry grape wines. Low-active transporter-receptor of inorganic phosphate with pH optimum in alkaline area was characterized recently in plasma membrane of this yeast. Earlier we have found out low-active (13.8 ± 0.4 nmol/min/1 mg of dry weight) plasma membrane dicarboxylate transporter sensitive to 2-undecyl malonate. It has been difficult to study because of its low activity and special properties. This S. cerevisiae transporter has alkaline pH-optimum and transports succinate more effectively, than citrate. After 15-18h of aerobic preincubation at 0°C of yeast cells, external Land D-malate stimulates respiration and 2-undecyl malonate inhibits oxidation of both substrates. However the malate oxidation becomes negligible after 24-26h of such preincubation. These stereoisomers competitively inhibits the succinate oxidation and transplasmalemmal transport of this dicarboxylate into cells limits respiration at that. Change of the incubation medium pH value from 5.5 to 6.5 causes growth of the ratio value of IC50 (one of the parameters of inhibition) of D-malate and IC50 of L-malate from 1.0 to 6.4. At the same time succinate dianion affinity varies a little bit. Such selective regulation of transplasmalemmal dicarboxylate transporter affinity may indicate that this carrier is a malate receptor and a probable sensor of extracellular pH.
https://doi.org/10.1142/9789814405041_0131
Controlled microbial catabolism of sterols can meet biotechnological applications. Three soil-screened strains: Rhodococcus sp. CIP 105335 (strain GK1), strain GK3 and strain GK12 were found to possess a high capability for sterol degradation. These were identified according to their morphology, morphogenetic cycle, physiology and cell wall chemo type to belong to the genus Rhodococcus. Besides, cholesterol oxidase of rhodococci is either released free and/or linked into the cell surface layer. This typical location was determined for the three strains and confirmed their appurtenance to the specified genus. The nucleotide sequence of the 16S rRNA gene, determined for GK1 and GK12, showed that the strain GK1 might be a R equi or a closely related species, and the isolate GK12 is a strain of Rhodococcus erythropolis.
https://doi.org/10.1142/9789814405041_0132
The adsorption of xylanase II on several polymers has been carried out. The adsorbents tested were oat spelt and beechwood xylan, microcrystalline cellulose, alkali-lignin washed with hot water or unwashed and wheat straw subjected to NaOH treatment and/or milling and sieving. The experimental results were fitted to the Langmuir isotherm and the adsorption parameters were determined. The best adsorbent was sieved wheat straw and the worst oat spelt xylan according with the maximum amount of enzyme that can be adsorbed (Eadmax). Lignin showed the minor Kes (adsorbent concentration necessary to adsorb half the protein) and cellulose showed the major Kes. Untreated sieved straw was better adsorbent of xylanase than NaOH treated and sieved straw.
https://doi.org/10.1142/9789814405041_0133
Thermophilic chitin-degrading bacterium, strain TC22-2b, was isolated from pruning tree compost. The cells of this strain were Gram-positive, straight-rod-shaped and motile. Ellipsoidal spores were formed in swollen sporangia. The temperature and pH ranges for growth were 25-58°C and pH 6-9, with optimal growth at 50-55°C and pH 7-8, respectively. The 16S rDNA sequence of the strain TC22-2b showed significant similarities to the sequences of Paenibacillus spp. However, there was no sequence showing over 94% similarity with strain TC22-2b in the DNA data base, indicating that this isolate might be a new species of the genus Paenibacillus. The SDSPAGE activity staining experiments suggested that strain TC22-2b had two kinds of chitinases. The crude enzyme recovered from a supernatant of culture showed highest chitinase activity at 70°C, pH 7. The chitinase of strain TC22-2b was thermostable and retained about 80% of the initial activity after 24 hours-preincubation at 60°C. The substrate GlcNAc6 was degaraded into GlcNAc4, GlcNAc3 and GlcNAc2 by this enzyme.
https://doi.org/10.1142/9789814405041_0134
Morphology of fungal pellets has a significant influence on mass transfer and turnover processes in submerged cultures. High-viscosity fermentation broth can lead to mixing and oxygen mass transfer limitation, obvious solution for this problem is to increase agitation intensity. Product formation of mycelial organism, like Aspergillus tamarii, is intimately connected with their morphology. Therefore, it is important to study the influence of the hydrodynamic conditions on the morphological development. Measurement of metabolic heat has been attempted using continuous and dynamic heat balance methods in a real time calorimeter (BioRTCal). In the present study, pellet morphology and protease production were studied under different agitation intensities of A. tamarii ie coupling of hydrodynamics and bioreaction, highlights the complex relationship between energy dissipation, substrates uptake rate and cell physiology. Monod-kinetics used to describe growth and product formation with a substrate affinity of 1.3 mg/mL.
https://doi.org/10.1142/9789814405041_0135
Homing endonucleases (HEs) are enzymes that invade specific insertion sites by generating double-strand breaks on the targeted gene. The insertion process results in HE duplication into recipient alleles of host genes lacking such a sequence. This enzymatic activity involves site-specific recombination events that can be exploited for the correction of DNA sequences in biotechnological and medical applications. The chloroplast-encoded largesubunit ribosomal RNA gene of lichen-forming algae belonging to the Trebouxia genus has diverse group I introns, which encode for LAGLIDADG-HEs. To search for new HEs, we explored the presence of group I introns in the same gene in both lichen-forming and free-living algae belonging to the Coccomyxa genus. Preliminary results indicated the presence of a relatively high number of group I introns in the analyzed specimens. Most of these introns showed ORFs encoding putative LAGLIDADG homing endonucleases. A number of these HEs seemed to be homodimers since they had a single LAGLIDADG motif, whereas others seemed to be monomers since they had two of these motifs. Group I introns in Coccomyxa algae were similar to those previously found in Trebouxia algae, but HEs had generally more amino acids residues. These findings reveal that lichen-forming algae are potential sources of new endonucleases that can be engineered to modify specific targets of interest.
https://doi.org/10.1142/9789814405041_0136
Enzymes are biocatalysts of great industrial interest. The enzyme application has increased by technological and economic reasons. Scientific research has been conducted for the production of metabolites of commercial value by microorganism in the presence of industrial wastes as nutrient sources. The aim of this work was to determine theproteolytic activity from Bacillus licheniformis in the presence of industrial wastes. The maximum average production of proteases was 174 - 176 U/mL in the presence of whey (byproduct of dairy industry) and glycerin (waste of biodiesel production). Industrial wastes can be used as nutrient sources in the production of proteases by B. licheniformis.