盐霉素自身抗性高产突变菌株筛选

摘要

目的 筛选出具有自身次级代谢产物盐霉素(salinomycin)抗性并且遗传稳定性好的菌株,提高摇瓶效价.方法 采用常规化学试剂甲基磺酸乙酯诱变处理盐霉素生产菌株Streptomyces albusS-13孢子,通过系列salinomycin浓度梯度平板进行筛选.结果 获得了比生产对照菌株高38％的突变株S-E-6.传代实验表明:S-E-6具有较好的遗传稳定性.同时,通过对盐霉素梯度筛选突变株的单菌落直径与效价进行了统计分析,结果表明突变株菌落直径与盐霉素效价具有正相关特性,线性相关系数(R2)为0.95.%Objective To obtain high-yield and genetic stable mutants of Streptomyces albus using a self-resisitance secreening method. Methods Spores of a Streptomyces albus strain S-13 for industrial production of salinomycin were treated by a chemical mutagen of ethylmethane sulfonate(EMS) and then secreen mutants grown on the salinomycin gradient plates. Results A mutant, designated S-E-6, was successfully selected using a salinomycin gradient plate method. The mean salinomycin titer of S-E-6 was 38% higher than that of the parent strain in flask culture. Also, the production level of the mutant S-E-6 was stable after successive 3-generation subcultures, indicating that the selected mutant has a good genetic stability for salinomycin biosynthesis. Besides, the correlation between the radius of colonies grown on salinomycin gradient plates and their corresponding titers was analyzed, the results show that there is a linear relationship with a correlation coefficient (R2) of 0.9546.