Isolation, purification and properties of a thermostable chitinase from an alkalophilic Bacillus sp. BG-11

An alkalophilic, chitinase-producing Bacillus sp. BG-11 was isolated which produced an extracellular chitinase and which was purified 16.5-fold, using standard purification techniques. The purified chitinase exhibited a broad pH and temperature optima of 7.5-9.0 and 45 degrees C-55 degrees C, respectively. The chitinase was stable between pH 6.0-9.0 and 50 degrees C for more than 2 h. Half lives of enzyme at 60 degrees C, 70 degrees C and 80 degrees C were 90 min, 30 min and 20 min respectively. K-m value was 12 mg chitin per ml. Shelf life was 60 days at 4 degrees C. Ca2+, Ni2+ and Triton-X-100 stimulated the activity up to 20% whereas Ag+, Hg2+, dithiothreitol, beta-mercaptoethanol, glutathione, iodoacetic acid and iodoacetamide inhibited the activity up to 50%.