Abstract

Chitinase was isolated and purified from Gliocladium catenulatum through ammonium sulfate sedimentation, sephadex G-25 gel filtration, deionization, ultra filtration condensation, negative ion exchange separation, and non-denaturing gel electrophoresis. A 51 kDa chitinase was purified from the fungus through sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optimum temperature and pH for chitinase activity were 60°C and pH 6.0, respectively. The enzyme solution was stable from 20 to 40°C and pH 4 to 5. Co²⁺ and Ca²⁺ were conducive to the enzyme activity, whereas the Fe³⁺, Cu²⁺, and Ag⁺ evidently inhibited the enzyme activity. Fe²⁺, Na⁺, K⁺, Zn²⁺, and Mn²⁺ showed less inhibitory effects on the enzyme activity. The K_m of the chitinase was 2.832 mg ml^-1. The chitanase were found to inhibit the hyphal growth, conidial germination and sclerotial germination of various plant pathogenic fungi.

Key words: Gliocladium catenulatum, chitinases, purification, characteristics.