Production of endoglucanase by optimizing the environmental conditions of Bacillus circulans on submerged fermentation

Cellulase is a complex enzyme system. It has got very high biotechnological potential for applications in different industries, such as food, brewery, wine, pulp, paper, textile, detergent, feed and agriculture. In this study, cellulolytic enzyme activity, particularly endoglucanse of ten Bacillus strains isolated from decomposed rice bran was examined, including one isolate selected on the basis of potential cellulolytic activity on CYPE-agar (Carboxymethyl cellulose or CMC 1.0, peptone 0.5, yeast extract 0.5, K₂HPO₄ 0.1, MgSO₄ 0.02 and NaCl 0.5%; pH 910). The potential endoglucanolytic isolate was identified as Bacillus circulans using Bergey's Manual of Determinative Bacteriology. To enhance the production of endoglucanse in the broth culture, different environmental conditions (time, temperature and pH) were tested. The maximum endoglucanse activity (6.6 U/mL ± 0.58SD) was achieved at optimized conditions (pH 9.0, temperature 45°C for 72 hours) on compared to control. However the effect of environmental conditions on endoglucanse induction diverged with strains in some extent.