Isolation and enzyme production of a cellulase-producing Bacillus sp. 79-23 = Cellulase를 생산하는 Bacillus sp. 79-23 분리와 효소 생산성

Abstract

A bacterium producing the extracell- ular cellulases was isolated from soil and has been identified as Bacillus sp. The isolate, named Bacillus sp. 79-23, was shown to be very similar to B. subtilis on the basis of its biochemical properties. The carboxymethyl cellulase (CMCase) of culture supernatant was most active at 60°C and pH 6.0, and retained 90% of its maximum activity at pH 7.0. The additional carbon sources affected the CMCase productivity than nitrogen sources in the culture medium. The carbon sources including wheat bran, rice straw, maltose and glucose increased the enzyme productivty. Especially, the maximum CMCase production was 5.2 units/ml in LB medium supplemented with 3% (w/v) wheat bran, which was 13-folds more than that in LB medium. It was found that the enzyme production was in association with the growth of Bacillus sp. 79-23. But, whean bran did not affect the growth of isolate, suggesting that increasement of CMCase production was owing to the induction of CMCase biosynthesis by wheat bran. In addition, both water-soluble and insoluble components of wheat bran was involved in induction of CMCase biosynthesis.