[Production and properties of chitinase from Beauveria bassiana Bb174 in solid state fermentation].

Abstract

This paper studied the chitinase production of Beauveria bassiana Bb174 under solid state fermentation condition. The optimal medium consisted of wheat bran and silkworm chrysalis at the ratio of 4:1, supplemented with 1 g peptone L(-1) as nitrogen source and some other mineral nutrients. The enzyme activity reached 126 units per gram dry medium after cultured for 2 days at 28 degrees C and natural pH by inoculated 3 ml spore suspension into this medium. The optimal temperature and pH for chintinase production were 40 degrees C and 5.0, respectively. The temperature to lose 50% activity of the enzyme was 48 degrees C after incubated at 30-70 degrees C for 1 h. The enzyme was stable at 30-40 degrees C and pH 4-6, and the Km and Vmax values were 0.52 mg x ml(-1) and 0.7 deltaE680 x h(-1), respectively.