雄甾烯酮转化菌的诱变育种和发酵条件优化

Mutant and Optimization of Androstenone Translation Strain Mycobacterium sp. SH5

采用紫外线照射和NTG对实验室保存的一株对植物甾醇有降解能力的Mycobacterium sp. SH5进行诱变处理,得到一株雄甾-4-烯-3,17-二酮(Androst-4-end-3,17-dione,AD)和雄甾-1,4-二烯-3,17-二酮(Androst-1,4-end-3,17-dione,ADD)分解酶(9α-羟化酶)缺陷型菌株Mycobacterium sp.SH5-52。对Mycobacterium sp. SH5-52降解植物甾醇侧链得到AD(D)的培养基组成、接种量、温度、pH值和溶氧等发酵条件进行了研究。在最佳的发酵条件下,投料质量浓度为0.6 g/dL时,AD(D)的转化率由原来的37.2%提高到47.6%左右。

Mycobacterium sp.SH5 was a potential strain for degrading phytosterol.After mutation by UV and NTG,a mutant with 9α-hydroxylase defective was selected and named as Mycobacterium sp.SH5-52.On the basis of mutation,the nutritional and environmental conditions of Mycobacterium sp.SH5-52 were investigated and optimized.With the optimum conditions,Mycobacterium sp.SH5-52 could degrade 0.6% substance phytosterol to Androst-4-end-3,17-dione（AD） and Androst-1,4-end-3,17-dione（ADD） with the average conversion ratio significantly improved from 37.2% to 47.6%.