达托霉素生产菌的激光诱变及组合抗性筛选

Laser Mutation and Combined Antibiotics Resistance Selection to Daptomycin Producing Strains

摘要: 本文结合He-Na激光诱变技术及抗生素抗性筛选方法选育达托霉素高产菌株。以达托霉素生产菌玫瑰孢链霉菌DA15-2为出发菌株，利用激光技术进行诱变育种，结果通过对致死率和正突变率的考察，适宜的诱变剂量为辅照功率20 mW及辅照时间20 min。在不同浓度梯度的达托霉素及链霉菌复合抗性平板上筛选诱变后的菌株，筛选到一株产达托霉素发酵单位100 mg/L的菌株DA15-23，比出发菌株提高了75.8%。实验证明结合激光诱变及抗生素抗性筛选得到了高产达托霉素的菌株。

Abstract: In this paper, He-Na laser irradiation and antibiotics resistance selection method were used to screen daptomycin high-producing strains. He-Na laser irradiation was applied to screen dapto-mycin high-producing strain from original strain of Streptomyces roseosporus DA15-2. The optimum mutagenesis dose was irradiation power 20 mW and irradiation time for 20 min, which was determined based on survival rate and positive mutation rate. The mutant strains on the plates of combined antibiotics resistance of daptomycin and Streptomyces at different concentrations were screened and a mutant strain DA15-23 was obtained, whose yield of daptomycin was 100 mg/L, which increased 75.8% compared to that of the parental strain. It was demonstrated that laser irradiation and antibiotics resistance selection combined method provided a fast and effective way of screening Streptomyces roseosporus.