中生菌素高产菌株的选育

SELECTION OF HIGH-YIELD STRAINS OF ZHONGSHENGMYCIN

通过中生菌素高产菌株初筛研究,得到在培养基的 pH 值为7.0时,菌落琼脂柱对指示菌抑菌圈的大小与其产素量成正相关;在此基础上,比较了用紫外线处理、低温加紫外线复合处理、原生质体加紫外线复合处理及原生质体融合等4种育种方法,结果所用方法都能有效地提高中生菌素产生菌的效价,其中原生质体加紫外线处理的方法最佳。最终得到了4株高产菌株,产素量比亲株提高了50%～90%,达到5000～6500μg/mL。

Through studying on the initial screening method of high-yield strains of Zhong- shengmycin(ZS),we found that,when the pH of test medium was 7.0,the size of agar column against bacteria was in direct correlation with its product.Based on this, comparisons were made among four screening methods:(1)treatment of UV,(2) combined treatment of low temperature(-20℃)and UV,(3)combined treament of protoplast and UV,(4)protoplast fusion.While all these four methodsincreased the effective yield of ZS,and the third method was the best.Four high-yield strains were obtained,and their yields were increased by 50%-90%,as high as 5000- 6500μg/ml.