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Grand Challenges in Biodiversity Informatics.

Using Biodiversity Information Effectively.

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.

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.