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The potential therapeutic value of bromelain is due to its biochemical and pharmacological properties and hence, it is desired to obtain bromelain in its highest purified form. Crude bromelain extract can be obtained from the fruit of Ananas comosus using ion exchange chromatography. Bromelain thus obtained can be subjected to either spray or freeze drying. The resulting residual activity and the specific activity were compared between the spray and freeze dried powders. Freeze dried bromelain was found to posses the specific activity twice as compared to the spray dried powder. The effect of protective agents and the bulking agents on the retention of activity was studied in both spray as well as freeze drying. The initial results have been encouraging as 90 % of the bromelain recovery was possible.

Cholera toxin B subunit (CTB) mature protein was stably expressed in transgenic tobacco plants under the control of CaMV 35S promoter and TMV Ω fragment. Fusion of the PR1b signal peptide coding sequence to the CTB mature protein gene increased the expression level by 24-fold. The tobacco-synthesized CTB (tCTB) was purified to homogeneity by a single step of immunoaffinity chromatography. The purified tCTB is predominantly in the form of pentamers with molecular weight identical to the native pentameric CTB, indicating the PR1b-CTB fusion protein has been properly processed in tobacco cells. Futhermore, we have shown that the antigenicity of the purified tCTB is indistinguishable from that of the native CTB protein by immunodiffusion and immunoelectrophoresis.

Xylitol is used as a natural sweetener in food products as well as a source of energy in infusion therapy and in the prevention of otitis media, osteoporosis, lung infection and myoadenylate deaminase deficiency. Xylose may be reduced to xylitol by NADPH-linked xylose reductase (E.C.1.1.1.21) (XR), a beneficial economic alternative for the catalytic hydrogenation of pure xylose, obtained from lignocellulosic hydrolisates. The purpose of this work is to evaluate the bioconversion of xylose to xylitol using purified XR and glucose 6-phosphate dehydrogenase as an auxiliary enzyme in order to reduce the cofactor NADP to NADPH required for the XR activity. For such a purpose, cells were disrupted by sonication and the supernatant was diluted to 1:4, 1:5 and 1:10 (v/v) for a further ultracentrifugation process using Amicon Ultra-15 Centrifugal Filter devices. The bioconversion of xylose into xylitol using both XR and G6PDH enzymes was done in a batch assay at room temperature. The partial purification yields of XR attained for 1:4, 1:5 and 1:10 dilutions were respectively 45.6, 64.5 and 67.2%. The use of both XR and G6PDH for the xylitol production reached a yield of 35.5%.

Streptomyces spp. produces many secondary metabolites, including antibiotics. The substances formation is coupled with the onset of development of the microorganism and the search of new substances is important. The aim of this work was to evaluate the bioactivity of endophytic Streptomyces tubercidicus isolated from Solanum lycocarpum St. Hill, a typical Brazilian tropical savannah tree to test its inhibitory capability against pathogenic bacteria and fungi. S. tubercidicus was cultivated in ISP2A and submitted to antibiosis test against S. aureus (ATCC 29213), P. aeruginosa (ATCC 27853), E. coli (ATCC 25922) and C. albicans (ATCC 10231). S. tubercidicus presented antibiosis against S. aureus (35 mm), E. coli (40 mm) and C. albicans (19 mm), but failed to inhibit P. aeruginosa. Purification of crude extract of S. tubercidicus with permeation in Sephadex L20 gel methanol revealed two compounds with bioactivity against S. aureus and E. coli.

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.

Flavonoids were extracted from bamboo stem via heat reflux using ethanol solvent as solvent. Extraction condition is explored experimentally in this paper, the optimal extraction conditions were as follow: alcohol/water volume ratio is 6:4, extraction time is 2 hours, extraction temperature is 80 °C, and material/solvent ratio is 1:20 (g/mL). During the purification process, cobalt ion was selected to complex with flavonoids and then disodium ethylenediamine tetraacetic acid (EDTA) was used to dissociate the cobalt-flavonoids complex. The extraction yield of flavonoids is 1.79% under the optimal extraction condition and flavonoids content can be increased to 50.8% after purification.