Chitosanase activity of the enzyme previously reported as beta-1,3-1,4-glucanase from Bacillus circulans WL-12

Chitosanases 33 kDa and 40 kDa in size were detected in the culture superna tant of Bacillus circulans WL-12. One of the two chitosanases, chitosanase 40 (40-kDa chitosanase) has been shown to be identical to the enzyme which has been reported previously as a beta-1,3-1,4-glucanase by Bueno et al.(1) ) The enzyme has been classified into family 8 glycosyl hydrolases together with the enzymes formally known as cellulase family D. This enzyme named c hitosanase 40/beta-1,3-1,4-glucanase hydrolyzed both chitosan and beta-1,3- 1,4-glucan with similar efficiency. However, the production of the enzyme w as induced with chitosan but not by beta-1,3-1,4-glucan. Therefore, it seem s possible that the major substrate of this enzyme is chitosan rather than beta-1,3-1,4-glucan, Analysis of degradation products generated from partia lly N-acetylated chitosan showed that chitosanase 40/beta-1,3-1,4-glucanase hydrolyzes GlcN-GlcN and GlcN-GlcNAc linkages but not GlcNAc-GlcNAc nor Gl cNAc-GlcN. The specificity for hydrolyzing linkages of this enzyme is simil ar to that of the chitosanase from S. griseus HUT6037.