核糖体工程技术选育ε-聚赖氨酸高产菌株

Screening of high-yield ε-poly-L-lysine producing strains through ribosome engineering

【目的】利用核糖体工程技术选育Streptomyces albulus AS3-14的链霉素和利福平双重抗性突变株,以提高其ε-聚赖氨酸合成能力。【方法】通过链霉素抗性筛选,获得链霉素抗性的ε-聚赖氨酸产量提高突变株;在此基础上,继续筛选其利福平抗性突变株,实现链霉素和利福平双重抗性ε-聚赖氨酸高产菌选育。【结果】获得的双重抗性高产突变株Streptomyces albulus WG-608的ε-聚赖氨酸摇瓶产量达到3.7 g/L,5 L发酵罐补料分批发酵ε-聚赖氨酸产量达到53.0 g/L,较出发菌株分别提高了42.3%和32.5%。【结论】链霉素和利福平双重抗性选育能够显著提高ε-聚赖氨酸产生菌Streptomyces albulus的产物合成能力。

[Objective] We used ribosme engineering technology, with which antibiotic-resistant strains are resulted from mutations on microbial ribosme, to improve the capacity to produce ε-PL by Streptomyces albulus AS3-14. [Methods] A single drug-resistant mutant was obtained from the original S. albulus AS3-14 with the presence of mutagen of streptomycin. A double drug-resistant mutant S. albulus WG-608 was obtained on the basis of single drug-resistant mutant with the presence of mutagen of rifampicin, of which the ε-PL productivity was improved. [Results] The highest ε-PL-producing strain, named S. albulus WG-608, could produce ε-PL of 3.7 g/L in shake-flask and 53.0 g/L in a 5-L fermentor, 42.3% and 32.5%, respectively higher than that of the parent strain. [Conclusion] Screening of streptomycin and rifampicin resistant strains might be a promising alternative to obtain a high ε-PL-producing S. albulus strain.