为提高菌株avermectin的产量 ,本文以链霉素抗性为选择压力 ,对除虫链霉菌Streptomycesavermi tilis进行紫外诱变 (2 53 7nm ,30w ,照射时间 45s) ,得到在摇瓶发酵水平比出发菌株产量提高 2 5 %以上的 4株突变株 ,其中 2株提高水平达 30 %以上。实验表明了链霉素抗性突变与产抗生素突变之间的密切联系。同时 ,对其机理和意义作了一些探讨 In order to improve the yield of avermectin, Streptomyces amblymi tilis was mutagenized with streptomycin resistance (2 537nm, 30w, irradiation time 45s) The yield of 4 more than 25% mutant strains, of which 2 to raise the level of more than 30%. Experiments show that there is a close relationship between streptomycin resistance mutations and antibiotic-producing mutations. At the same time, some discussions have been made on its mechanism and significance