Studies on cellulase production by a Bacillus subtilis.

Bacillus subtilis AU-1 was found to produce carboxymethylcellulase (CMCase) and Avicelase activities in the culture supernatant when grown on a variety of carbohydrates as major carbon source. Maximum CMCase production was obtained in a liquid medium containing 0.2% D (+) raffinose as inducer, 0.5% each of yeast extract, casamino acids and proteose peptone at 50 degrees C and at an initial pH of 6.0. CMCase activity was detected at early log phase of growth, and reached the maximum level at early stationary phase of growth which occurred at the 10th hour of cultivation. The optimal temperature for CMCase activity was 65 degrees C, and the enzyme was highly stable up to 60 degrees C. CMCase synthesis was subjected to catabolite repression by glucose and cellobiose.