微波诱变结合抗性突变筛选放线菌素D高产菌株

采用微波结合链霉素抗性筛选法选育放线菌素D的高产菌株。通过考察链霉素对Streptomyces rubiginosohelvolus FIM-N31菌株孢子生长情况的影响确定链霉素致死浓度，出发菌株FIM-N31的孢子经微波辐照处理后，涂布在含链霉素致死浓度（50 μg/mL）的培养基平板上培养，获得了大量的链霉素抗性基因突变株。摇瓶发酵筛选突变株，结果获得一株遗传性状稳定的放线菌素D高产菌Str186，其产放线菌素D的能力比出发菌株提高了8倍以上。

Screening of Actinomycin D High-producing Strain by Streptomycin Resistant Mutant Selection Coupled with Microwave Mutagenesis

Microwave mutagenesis and streptomycin resistance screening was applied to screen actinomycin D high-producting strain. After testing the resistance of Streptomyce rubiginosohelvolus FIM-N31 to streptomycin, the lethal concentration of streptomycin was determined. A lot of streptomycin-resistant mutants were screened after the spores regenerated on the lethal streptomycin concentration (50 μg/mL) media when they were treated with microwave irradiation. It was eventually found that the high-yield strain Str186 from these mutants which was stably inheritable, and the productivity was beyond eight times higher than the original strains in the rotation-flask experiments.