The Bacillus subtilis 168 csn gene encodes a chitosanase with similar properties to a Streptomyces enzyme

The Bacillus subtilis 168 csn gene encodes a chitosanase. It was found that transcription of the csn gene was temporally regulated and was not subject to metabolic repression. Chitosanase synthesis was abolished in a csn muta nt strain. Csn was overproduced in B. subtilis, partially purified and char acterized. The deduced amino acid sequence, K-m, and optimal pH and tempera ture of the B. subtilis enzyme were closer to those of a chitosanase from S treptomyces sp. N174 than to those of chitosanases from other Bacillus stra ins.