链霉菌LA5高产菌株诱变育种研究初报

Preliminary Research on Mutation Breeding of Streptomyces sp. LA5 Strain for High Yield Antibiotics

抗生素LA5具有开发成抗真菌农用抗生素的广阔前景,但由于该菌株的野生型菌株发酵效价低,不能满足工业化开发的要求。通过以链霉菌LA5为出发菌株,采用紫外线(UV)、微波、亚硝基胍(NTG)、紫外线+亚硝基胍、亚硝基胍+紫外线等方法进行诱变筛选,结果表明,以紫外线照射80 s+亚硝基胍处理80 min的诱变的正突变率最高,为30%,其他依次为亚硝基胍处理80 min+紫外线照射40 s诱变和亚硝基胍处理60min+紫外线照射120 s诱变,正突变率均为26%。然后依次使用亚硝基胍处理80 min+紫外线照射80 s、亚硝基胍处理80 min+紫外线照射40 s、亚硝基胍处理60 min+紫外线照射120 s进行第2、第3、第4轮复合诱变筛选,最后选育出突变菌株U8-N8A-196,其产抗生素能力比链霉菌LA5出发菌株提高了34.5%,极显著高于LA5菌株。

Antibiotic LA5 has wide prospect on antifungal activities in agricultural antibiotic. But, the potency of Streptomyces sp. LA5 strain is rather low, and can not meet the requirement of industrious manufacture. Streptomyces sp. LA5 was selected as the starting strain by ultraviolet, microwave, NTG, UV ＋ NTG and NTG ＋ UV. The best effective mutant UV 80 sec ＋ NTG 80 rain was gained, with 30% positive mutation rate, and NTG 80min ＋ UV 40 sec and NTG 60 min ＋ UV 120 sec with 26% positive mutate rate. Then treated UV 80 sec ＋ NTG 80 rain, NTG 80 min ＋ UV 40 sec and NTG 60 min ＋ UV 120 sec for the second, third and the fourth mutation, and finally a positive mutant U8-N8A-196 was obtained , with 34.5% higher ability of producing antibiotic than Streptomyces sp. LAS.