瑞拉菌素产生菌RL-2的诱变育种

Mutational Screening of Zuelacmycin-producing Strain RL-2

本研究以委内瑞拉链霉菌秦岭变种RL-2(Streptomyces venezuelaevar.qinlingensis RL-2)为出发菌株,分别采用紫外线、氯化锂及紫外线加氯化锂的复合诱变方式对其孢子悬液进行诱变处理。在复合诱变的紫外线照射时间为45s和氯化锂浓度为0.4%的情况下,获得一株瑞拉菌素的高产突变菌株UVL-108且连续传接6代其遗传特性较稳定。采用双向培养及生长速率法对其进行初筛和复筛,结果表明:UVL-108的拮抗性能较出发菌株提高了77%,其发酵液对稻瘟病菌的抑菌毒力是出发菌株的3倍。

In this research, the zuelacmycin-producing strain Streptomyces venezuelaevar, qinlingensis RL-2 was used as original strain, the spore suspension of which was induced by UV, LiCl and the compound treatmeat （UV＋LiCl） respectively. The zuelacmycin-high-yield strain UVL-108 was obtained by the treatment that the exposure time under UV irradition was 45 s and the concentration of LiCl was 0.4%. The heredity characters of mutant UVL-108 were stable in succesive six generations. The antibacterial activity and the fermentation titer of mutant UVL-108 were determinded by bidirectioned culture and mycelial linear growth respectively. The results demonstrated the antibaterial activity of mutant UVL-108 was improved by 77%, and the relative toxicity of fermentation to Phyricularia grisea was improved by two times compared with the original strain.