西藏米拉山草甸土壤PKS和NRPS基因多样性

为了解西藏米拉山草甸土壤中的聚酮合成酶(PKS)基因和非核糖体多肽合成酶(NRPS)基因多样性,采用直接提取土壤总DNA,PCR扩增Ⅰ型PKS基因KS域和NRPS基因A域,并在NCBI进行Blast比对,分析其系统进化发育.得到27个PKS基因KS片段,经NCBI比对,主要来自蓝细菌(Cyanobaeteria)、α-和γ-变形菌(Proteobaeteria)和不能培养的微生物,得到NPRSA片段32个,主要属于变形菌门、蓝细菌门等.

Phylogentic analysis of type I polyketide synthase and nonribosomal peptide synthetase genes from Mila Mountain in Tibetan Plateau

The modular polyketide synthase(PKS) and nonribosomal peptide synthetase(NRPS) were found to be involved in natural product synthesis in many microorganisms. Study on their diversities in natural environment may provide important ecological insights besides opportunities for antibacterial drugs development. The phylogenetic analysis of amino acid(AA) sequences indicated that the identified ketosynthase(KS) domains were clustered with those from diverse bacterial groups, including Cyanobaeteria, Proteobaeteria and some uncultured symbiotic bacteria. The NRPS included Cyanobaeteria and Proteobaeteria. One new branch belonging to hybrid PKS/NRPS enzyme complexes and five independent clades were found on the phylogenetic tree. These results revealed the great diversity and novelty of both PKS and NRPS genes from Mila Mountain in Tibetan Plateau.