Production of cellulases from a novel thermophilic Streptomyces thermocerradoensis I3 using agricultural waste residue as substrate

Abstract

Cellulases and hemicellulases are key enzymes in the utilization of lignocellulosic biomass, an abundant renewable source. In this work, cellulase production by a new thermophilic Streptomyces thermocerradoensis was analyzed by cultivation on medium containing carboximethyl cellulose, sugarcane bagasse or wheat bran as carbon source. The best results were obtained with wheat bran. The cellulolytic activity was evaluated by determination of Avicelase, CM Case and FPase activities. Cellulolytic enzymes were characterized by determining the effect of pH and temperature, thermo stability and effects of different metal ions on activities. The pH and temperature profile showed optimal activity at pH 7.0/35° C for Avicelase, pH 4.5/75° C for CMCase and pH 5.0/45° C for FPase. Zymogram analysis showed the presence of multiple cellulases (45, 19 and 17 kDa). The three cellulolytic activities evaluated maintained over 50% of initial activity, even after 4 hours of incubation at 60° C. Cellulases studied in this work are thermophilic, thermos table and active in a wide pH range. They have potential to be used in the development of new biotechnological processes.