Chitobiose production by using a novel thermostable chitinase from Bacillus licheniformis strain JS isolated from a mushroom bed

The thermophilic Bacillus licheniformis strain JS was isolated from a bed of mushrooms, Pleurotus sajor-caju. The organism could produce a novel, single-component, thermostable chitinase that was purified by ion-exchange chromatography using DEAE-cellulose in 7.64% yield and in an 8.1-fold enhancement in purity. Its molecular weight is 22 kDa. The enzyme is a chitobiosidase, since the chitin hydrolysate is NI,NII-diacetylchitobiose. The optimum temperature for enzyme activity is 55 °C, and the optimum pH is 8.0. It was completely inhibited by Hg2+ ions whereas Co2+ ions served as an activator. The thermostability of this enzyme is important in the bioconversion of chitinous waste and for the production of chitooligosaccharides.

HPLC analysis of hydrolyzed product of colloidal chitin by purified chitinase of Bacillus licheniformis strain JS. The B. licheniformis strain JS could produce a novel single-component thermostable chitobiosidase with molecular weight of 22 kDa.Figure optionsDownload as PowerPoint slide