恰塔努加链霉菌L10中黄色素生物合成途径的研究

链霉菌中聚酮合酶合成的次级代谢产物数量众多结构复杂，这些合成途径之间相互竞争合成前体，对目标产物的产量和分离纯化都造成负面影响。纳他霉素工业菌株恰塔努加链霉菌L10在发酵生产类型I PKS产物纳他霉素的同时还产生一种类型II PKS产物黄色素，严重影响纳他霉素的产量和质量。本项目针对L10产生的黄色素，通过化学、生物信息学、遗传学和酶学等手段阐明其分子结构、合成基因簇和生物合成途径，拓宽人们对链霉菌PKS产物的生物合成途径以及各个合成途径之间相互竞争关系的认识，并为链霉菌PKS合成的抗生素的优质高产打下基础。

Streptomyces produce secondary metabolites biosynthesized by polyketide synthases with a large numbers and complicated structures. These biosynthetic pathways compete each other by using same substrates. The presence of mutiple PKS products usually affects both the yield and the purity of target product. The natamycin industrial producer, S. chattanoogensis L10, produces the type I PKS product natamycin as well as a type II PKS product yellow pigment. The presence of the yellow pigment affects both the yield and the purity of natamycin. The aim of this project is to elucidate the molecular structure of the yellow pigment, the biosynthetic gene cluster, and the biosynthetic pathway by chemical, bioinformatic, genetic, and enzymologic techniques. The results will expand the understanding of the biosynthetic pathway of PKS products and the competion of the biosynthetic pathways in Streptomyces. The results also may help us to gene-engineer a mutant strain to produce PKS product with higher yield and higher purity.