Characterization of cellulase producing Bacillus sp. for effective degradation of leaf litter biomass



Cellulose degrading Bacillus spp. (AS1, AS2, and AS3) were isolated from cow dung and identified phylogenetically by 16S ribosomal RNA (16S rRNA) sequence analysis. Bacillus sp. AS1 showed 99% homology with Bacillus megaterium whereas, Bacillus sp. AS2 and AS3 were similar to B. subtilis. The activity of extracellular carboxymethyl cellulase in presence of 1% carboxymethyl cellulose at 50°C was 0.04 U/mL for Bacillus sp. AS1 and 0.06 U/mL for Bacillus sp. AS2 at pH 7.0, whereas higher activity of 0.08 U/mL was observed for Bacillus sp. AS3 at pH 9.0. Crude cellulase from all the three Bacillus sp. were stable over a wide range of pH (5.0–9.0) and thermally stable up to 60°C. Carboxymethyl cellulase, filter paperase, and β-glucosidase activity of Bacillus sp. AS3 was 0.07, 0.02, and 0.04 U/ml, respectively. Degradation of leaf litter biomass treated by Bacillus sp. AS3 showed 47% drop in carbon:nitrogen (C:N) ratio and x-ray diffractograph revealed decline in crystalline structure. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 1195–1201, 2013