葡甘聚糖酶高产菌株Bacillus subtilis的超剂量诱变育种

超剂量诱变育种就是加大诱变剂处理剂量,提高菌株突变幅度,从而获得较好的诱变效果.以葡甘聚糖酶产生菌Bacillus subtilis MY-1为初始菌株,先用紫外线、硫酸二乙酯进行单因子诱变,再用超剂量复合诱变,经过透明圈法和摇瓶筛选,得到了一株高产葡甘聚糖酶的突变菌株,命名为Bacillus subtilis UDMY-25,连续传代培养5次,发酵酶活稳定在5 387.2U/mL以上,较原初始菌株提高了44.8%,该菌株产酶能力处于同领域较高水平,具有较好的开发潜力和市场应用价值.

Overdose mutation breeding of Bacillus subtilis for producing glucomannanase

Excessive mutagenesis breeding is to increase the dose of mutagen treatment,increase the rate of mutation,so as to obtain better mutagenic effect.The research started from a parent strain Bacillus subtilis MY-1 which could produce glucomannanase.First,we used ultraviolet(UV),diethyl sulfate(DES)'s single factor mutagenesis,and then used composite mutagenesis of UV and diethyl sulfate to culture,as well as initial and secondary screening of the original strain Bacillus subtilis MY-1.By observing the clear circles on selective plates and rescreening with rescreening medium,we got a mutant strain named Bacillus subtilis UDMY-25 after serially passed 5 times' cultivation,which could produce high-yield glucomannanase and the genetic nature is stable,the enzyme activity(5 387.2 U/mL)increase 44.8% more than the original strain Bacillus subtilis MY-1.The ability of the strain to produce glucomannanase is the higher level of the same field,which has a good development potential and market value.