Potential of semiarid soil from Caatinga biome as a novel source for mining lignocellulose-degrading enzymes.

The litterfall is the major organic material deposited in soil of Brazilian Caatinga biome, thus providing the ideal conditions for plant biomass-degrading microorganisms to thrive. Herein, the phylogenetic composition and lignocellulose-degrading capacity have been explored for the first time from a fosmid library dataset of Caatinga soil by sequence-based screening. A complex bacterial community dominated by Proteobacteria and Actinobacteria was unraveled. SEED subsystems-based annotations revealed a broad range of genes assigned to carbohydrate and aromatic compounds metabolism, indicating microbial ability to utilize plant-derived material. CAZy-based annotation identified 7275 genes encoding 37 glycoside hydrolases (GHs) families related to hydrolysis of cellulose, hemicellulose, oligosaccharides and other lignin-modifying enzymes. Taxonomic affiliation of genes showed high genetic potential of the phylum Acidobacteria for hemicellulose degradation, whereas Actinobacteria members appear to play an important role in celullose hydrolysis. Additionally, comparative analyses revealed greater GHs profile similarity among soils as compared to the digestive tract of animals capable of digesting plant biomass, particularly in the hemicellulases content. Combined results suggest a complex synergistic interaction of community members required for biomass degradation into fermentable sugars. This large repertoire of lignocellulolytic enzymes opens perspectives for mining potential candidates of biochemical catalysts for biofuels production from renewable resources and other environmental applications.

Diversity of class 1 and 2 integrons detected in Escherichia coli isolates from diseased and apparently healthy dogs.

Escherichia coli is one of the major pathogens causing urinary tract infections (UTIs) and pyometra in dogs. The aims of this study were to investigate canine E. coli isolates for the presence of class 1 and 2 integrons by PCR/sequencing and to characterize these isolates and their integron-carrying plasmids. Isolates were characterized by phylotyping, XbaI-macrorestriction analysis and plasmid transfer experiments. Plasmids were analyzed by S1 nuclease-PFGE, replicon typing, conjugation and restriction analysis. Antimicrobial resistance was investigated by antimicrobial susceptibility testing and PCR/sequencing. From 158 E. coli of dogs suffering from UTIs (n=51) and pyometra (n=52) or being apparently healthy (n=55), 13 isolates harboured class 1 (n=10) or class 2 integrons (n=3). They were distributed among the phylogenetic groups A (3/13), B1 (6/13), B2 (3/13) and D (1/13). Two isolates showed indistinguishable XbaI-patterns, but differed in the remaining characteristics. Another two isolates (UTI or apparently healthy) displayed different XbaI-patterns, but harboured similar plasmids. Integrons were found on plasmids of incompatibility groups IncF, IncF-IncFIC, IncFIB-IncHI2, IncFIB-IncN, IncFIC or IncHI2 and three of them were conjugative. Resistances to aminoglycosides, sulphonamides and trimethoprim were commonly detected. Class 1 integrons carried the gene cassette arrays dfrA12-orfF-aadA28, ΔdfrA17-aadA5, dfrA29, aadA7, aadA29 or dfrA12-orfF-aadA2-cmlA1-aadA1. Class 2 integrons carried the array dfrA1-sat2-aadA30. Two extended-spectrum ß-lactamase genes (blaCTX-M-2) and one AmpC ß-lactamase gene (blaCMY-2) were also detected on plasmids. These findings indicate the potential risk of the dissemination and persistence of E. coli and/or integron-carrying plasmids in companion animals.

Draft Genome Sequence of the Biosurfactant-Producing Bacterium Gordonia amicalis Strain CCMA-559, Isolated from Petroleum-Impacted Sediment.

Gordonia amicalis strain CCMA-559 was isolated from an oil-contaminated mangrove swamp and shown to produce biosurfactants. This strain is a strict aerobe that readily degrades an array of carbon sources, including N-acetylglucosamine, cellobiose, Tween 80, and 4-hydroxybenzoic acid, and, like other G. amicalis strains, likely desulfurizes dibenzothiophene.

Draft Genome Sequence of Bacillus pumilus CCMA-560, Isolated from an Oil-Contaminated Mangrove Swamp.

Bacillus pumilus strain CCMA-560 was isolated from an oil-contaminated mangrove swamp and was shown to produce biosurfactants. The strain appears to be capable of degrading some plant cell wall-related compounds, including hemicelluose and pectin. Genes for biopolymer export and polysaccharide intercellular adhesin synthesis were also annotated.