Avermectin B_(1a)高效突变株的选育及发酵条件的优化

Screening and Optimizing of Fermentation Conditions of the Effective Avermectin B_(1a) Producing Strains from Streptomyces avermitilis

目的筛选获得Avermectins B1a高效突变菌株。方法通过离子注入诱变、紫外线与氯化锂复合诱变法处理阿维链霉菌出发菌株N-5-9。获得高效突变株,再对其进行发酵条件的优化,寻找最适发酵培养条件。结果筛选获得Avermectins高效突变菌株A-30-6,总效价达到6988.2μg·ml-1,B1a含量达到79.4%,较出发菌株N-5-9的B1a组提高46.3%。结论利用离子注入诱变、紫外线与氯化锂复合诱变方法,诱变效果显著,再进行发酵条件的优化,获得目的菌株。

Aim To obtain the effective avermectin Bla producing strains from Streptomyces avermitilis by screening. Mehtods Effective ways were used to obtain high-performace avermectin producing strains, including the method with ion implantation, the composite mutation method with ultraviolet（UV）-ray and lithium chloride in treating the original strains N-5-9. Then fermentation conditions were optimized to obtain the most suitable fermentation condition of mutation strain A-30-6. Results The mutation strain A-30-6 with the total titer up to 6 988.2μg·ml^-1 was obtained among high-yield avermeetins producing strains and also was proved to be stable effective avermectin Bla producer up to 79.4%. Its proportion of avermeetin Bla was 46.3% higher than that of the original strain N-5-9. Conclusion The mutation method with ion implantation and the composite method with ultraviolet （UV）-ray and lithium chloride are effective for to obtaining the goal stains whose total titer and component Bla are distinctly improved by mutations.