复合诱变选育壳聚糖酶高产菌种及产酶条件优化

以具有产壳聚糖酶能力的枯草芽孢杆菌（Bacillus subtilis）G10为出发菌，利用紫外和微波对菌株G10进行复合诱变，选育壳聚糖酶高产菌株，并采用正交试验设计对突变株产酶条件进行优化。结果选育出一株产酶活相对较高的突变株W1-32，优化后的产酶条件为果糖1.3%，胶体壳聚糖0.5%，酵母粉2.0%，MgSO4·7H2O 0.3%，初始pH 7.2，温度28 ℃，转速200 r/min。在此优化条件下，菌株W1-32产壳聚糖酶活为11.82 U/mL，是出发菌株G10的6.9倍。该研究为菌种的选育和进一步研究应用提供理论依据。

Breeding of high-yield chitosanase strain by compound mutation and optimization of enzyme production conditions

Using Bacillus subtilis strain G10 with chitosanase-producing ability as the starting strain, the high-yield chitosanase strain was bred by ultraviolet mutagenesis and microwave mutagenesis, and the culture conditions of the mutant strain producing chitosanase were optimized by orthogonal tests design. The mutant strain W1-32 with relatively high chitosanase activity was screened, and the optimized culture conditions for high-yield chitosanase were fructose 1.3%, colloidal chitosan 0.5%, yeast powder 2.0%, MgSO4 7H2O 0.3%, initial pH 7.2, temperature 28 ℃ and rotation speed 200 r/min. Under the optimal conditions, the chitosan activity pooduced by strain W1-32 was 11.82 U/ml, which was 6.9 times of that of the starting strain G10. The study provided a theoretical basis for the breeding of strains and further application study.