重离子束对北里链霉菌的诱变效应

Mutation Effect of Streptomyces kitasatoensis after Exposure to Heavy Ions Radiation

考察不同剂量重离子束对北里链霉菌的致死及诱变效应,可确定最有利于筛选高产菌株的重离子束辐照剂量。利用不同剂量的重离子束辐照北里链霉菌孢子,统计了存活率、致死率、正负突变率。结果发现,在5 Gy重离子辐照时北里链霉菌出现较高致死率,其后随剂量升高,致死率变化较平缓。各辐照剂量下正负突变率相比较,40 Gy时正突变率最高,负突变率相对较低,存活率为0.92%。因此确定40 Gy是对北里链霉菌高产菌株筛选最有利的辐照剂量。

To define the optimum dose of heavy ion beams for selecting high productive strains,we should study mortality and mutation effects of Streptomyces kitasatoensis irradiated by heavy ion beams in diffe-rent doses.In this research,spores of Streptomyces kitasatoensis were irradiated by heavy ion beams with different doses.And survival rate,mortality rate,positive mutation and negative mutation were analyzed statistically.The results showed that high mortality rate appeared from 5 Gy and then the mortality rate curve became gently.Compared the positive and negative mutations in different doses,highest positive mutation was obtained in 40 Gy,while the negative mutation was lower in this dose,and the survival rate was 0.92%.So we defined that optimum dose of heavy ions radiation for Streptomyces kitasatoensis selection was 40 Gy in this experiment.