基于多组学技术的淀粉酶产色链霉菌突变株高产ε-聚赖氨酸作用机制研究

ε-Polylysine has a wide range of antimicrobial activity and has been used as a bio-preservative. ε-Polylysine and ε-Polylysine•HCl have been approved used as new kinds of food additives by NHFPC in1994. But its high production costs restrict its wide application in china. Breeding of high yield strain through physical and chemical mutagenesis is a feasible method to reduce the ε-polylysine production costs. Analysis of mutant mechanism has become a scientific problem to be solved urgently at present. The high-yield mutant ε-polylysine producing strain Streptomyces diastatochromogenes 6#-7 was obtained through physical and chemical mutation methods, the yield increased by 41.07% compared with the starting strain Streptomyces diastatochromogenes TUST, which provides a good study material for the study of high yield ε-Polylysine synthesis mechanism of mutant strain. This project intends to determine the influence and regulation of ε-Polylysine synthesis key targets by analysis of genes, transcription, protein and metabolite levels differences between wild type ε-Polylysine producing strain and high yield mutant through use genomics, transcriptomics, proteomics and metabolomics technology，and systematic explain the mutant high yield ε-Polylysine mechanism, and provide a theoretical basis for the further improve the ε-Polylysine fermentation level. The results obtained in this study also can be used as a reference to reveal the mechanism of high yield mutants by physical and chemical mutagenesis.

ε-聚赖氨酸是一种广谱生物防腐剂，2014 年我国批准ε-聚赖氨酸及其盐酸盐作为新型食品防腐剂使用。由于生产成本高，限制了其在国内的广泛应用。通过理化诱变选育高产菌株是降低ε-聚赖氨酸生产成本的可行方法，解析高产突变株作用机制就成为目前亟待解决的科学问题。前期以ε-聚赖氨酸产生菌淀粉酶产色链霉菌TUST作为出发菌通过理化诱变手段得到高产突变株6#-7，产量较出发菌株提高41.07%，为研究突变株高产ε-聚赖氨酸合成机制提供了良好研究材料。项目拟采用基因组学、转录组学、蛋白质组学和代谢组学技术，对ε-聚赖氨酸产生菌原始菌株和高产突变株从基因、转录、蛋白质和代谢水平进行比较分析，确定影响ε-聚赖氨酸合成和调控的关键靶点，系统阐述突变株高效合成ε-聚赖氨酸的作用机制，为进一步提高ε-聚赖氨酸发酵水平提供理论依据。项目对于揭示其他通过理化诱变手段提高微生物产品发酵水平的高产机制也具有借鉴意义。