Optimization, Purification of Cellulase Produced from Bacillus subtilis subsp. inaquosorum under Solid State Fermentation and its Potential Applications in Denim Industry

A bacterial isolate from soil samples contaminated with decaying lignocellulosic wastes and effluents of cotton industry was isolated for cellulase production and was identified as Bacillus subtilis subsp. inaquosorum after morphological, biochemical and phlogenetic analysis. Under optimized solid state fermentation conditions maximum cellulase production 71.15 IU/ml was obtained with wheat bran as carbon source in MA-1 mineral media and fructose and yeast extract as additives under 48 hr of production period at 37 ̊C, with 30% inoculum size. Moisture level of 1:2 (w/v) was found best for cellulase production. The crude cellulase so produced was further analysed for its potential applications in biostoning of denim. The purification of cellulase was carried out by ammonium sulfate precipitation followed by ion-exchange chromatography using DEAE-Sepharose and Sephadex G -150. The molecular weight of the purified carboxymethylcellulase (CMCase) was estimated to be about 32.5 kDa with the analysis of SDS-PAGE.