[Rational screen of high kelimycin-producing strain by combined conventional mutagenesis and high-throughput screen method].

ABSTRACT

UNLABELLED Kelimycin, is a new macrolide antibiotic drug obtained through genetic engineering approaches. With 4"-O-isovalerylspiramycins as the major components, was produced by genetically engineered Streptomyces spiramyceticus transformed with 4"-O-acyltransferase gene from S. mycarofaciens. OBJECTIVE: Improve the efficiency of strain fermentation, to meet the needs of industrial production. METHODS: The enhanced kelimycin-producing strain was obtained by applying various conventional mutagenesis approaches, and high-throughput screen methods, including protoplast mutagenesis by ultraviolet, mutagenesis by diethyl sulfate and UV-reactivation, valine content resistance screen and enrichment of improved strains. A strategy for positive mutant enrichment was developed after mutagenesis and before high-throughput screen. RESULTS: Finally, the high-producing strain WSJ-1-7-49-133-82-18-43 was obtained and its potency in shake flask increased by 56% compared to the original strain. The potency in 500 L pilot fermenter increased by 61%. CONCLUSION: This study shows that the screening industrial production strains can be enhanced effectively by combining multiple conventional mutagenesis and high-throughput screen methods.