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

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. 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 N I, N II-diacetylchitobiose. The optimum temperature for enzyme activity is 55 °C, and the optimum pH is 8.0. It was completely inhibited by Hg 2+ ions whereas Co 2+ ions served as an activator. The thermostability of this enzyme is important in the bioconversion of chitinous waste and for the production of chitooligosaccharides.