盐霉素自身抗性高产突变菌株筛选

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 albus S-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。

Screening of high- salinomycin- yield mutants ofStreptomyces albus by self-resistance methodology

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.