紫外结合亚硝酸诱变选育中性蛋白酶高产菌株

Study on the screening high yield neutral-protease-producing strain by combing UV and nitrous acid mutagenesis

摘要: 为提高一株深海来源微小杆菌属细菌Exiguobacterium sp.SWJS2产中性蛋白酶的酶活,本文先后采用紫外线和亚硝酸对其进行诱变处理。紫外诱变条件为8W紫外灯在20cm处直接照射50s;三轮诱变后得突变株UV-48,其酶活较原始菌株提升21.32%。再以UV-48为出发菌株进行亚硝酸诱变,条件为0.03mol/L亚硝酸作用8min;三轮诱变后得突变株HN-34,其酶活为1109U/m L,较突变株UV-48提升13.97%,较原始菌株提升38.28%。HN-34传代5次相对酶活均在94%以上,遗传性状稳定。

Abstract: UV and HNO2 were successively used to promote the enzyme-activity of the neutral protease produced by a marine bacteria Exiguobacterium sp.SWJS2.Being directly exposed to 8W UV for 50 s with a vertical dimension of 20 cm,mutant strain UV-48 with a promotion of 21.32% were obtained after three turns of mutagenesis and then be applied into HNO2 mutagenesis for further promotion. Being diluted by 0.03 mol/L HNO2 for 8min,UV-48 was finally turned into HN-34 with a promotion of 13.97% than itself and 38.28% than the starting strain after three turns.After pass-generation tests for five times,the mutant strain HN-34 was proved to be genetically stable since the five relative enzyme-activity were all above 94%.