产葡萄糖氧化酶菌株的诱变筛选及遗传稳定性研究

采用平板显色初筛、Underbofler滴定法复筛及紫外-硫酸二乙酯复合诱变的方法，从临沂果园土样中得到一株产葡萄糖氧化酶（GOD）活性较好的菌株，命名为Bla-6，其产GOD酶活为（10.50±0.25） U/mL，与原始菌株LPA-4产GOD酶活（6.75 U/mL）相比提高了55.57%。结合5.8S rDNA-ITS区序列系统进化、菌落形态、生长特性、菌体形态等确定其分类地位。结果表明，所得菌株Bla-6被鉴定为黑曲霉（Aspergillus niger），经8代传代培养后，GOD酶活维持在10.5 U/mL左右，该菌株遗传稳定性较好。

Mutation screening and genetic stability of glucose oxidase-producing strain

By preliminary screening of plate coloration, secondary screening of Underbofler titration method, a glucose oxidase-producing strain was obtained from Linyi orchard soil samples, and named as strain Bla-6. The glucose oxidase (GOD) activity produced by strain Bla-6 was (10.50±0.25) U/ml, which was 55.57% higher than that (6.75 U/ml) produced by original strain LPA-4. By the analysis of 5.8S rDNA-ITS gene sequence, colonial morphology, growth characteristics, and mycelial morphology, the results showed that the strain Bla-6 was identified as Aspergillus niger . After subculture of 10 successive generations, the GOD activity maintained at about 10.5 U/ml, which showed that the strain had good genetic stability.