高产糖化酶菌株的筛选与诱变育种

Screening and Mutagenesis of Strain with High Yield of Glucoamylase

从土壤及霉变淀粉质材料等样品中分离获得到产糖化酶活性较高的菌株L-3,经鉴定为一种紫红曲霉;通过紫外线和硫酸二乙酯分别进行诱变,得到4株性能良好的糖化酶变异株,其中菌株7性能最好,命名为M.F7。对该菌株进行发酵性能测试,结果表明该菌株糖化酶活力比原菌株提高了20.8%;经过继代培养,证明其性状能稳定遗传。通过正交试验,确定菌株7最佳培养温度为30℃,最适pH值为5.5～6.0,最适培养时间为5 d。

The strain L-3 that could produce raw starch-digesting glucoamylase were isolated from soil and mildewed flee. It was identified to be a Monascus Purpureus. After UV and DES mutagenesis the screened glucoamylase strain, 4 mutation strains with outstanding capability was selected, there is the strain-7 with the best capability and was named M. F7. Its fermentation characteristics was tested, comparing to the parent strain, its enzyme activity was improved 20 % and was fostered by many generation with steadily inherited characters. The techniques conditions （ T = 30 ℃ ; pH 5.5 - pH 6.0 ; t = 5 d）of batch fermentation were optimized by orthogonal test.