基于LC-MS/MS和比较基因组学技术解析海洋源解淀粉芽孢杆菌CMT-9产抗菌脂肽的分子机理

Molecular mechanism of antimicrobial lipopeptide produced by marine Bacillus amyloliquefaciens CMT-9 analyzed by LC-MS/MS and comparative genomics

为探究海洋源解淀粉芽孢杆菌(Bacillus amyloliquefaciens)CMT-9产抗菌脂肽的分子机理。采用高效液相色谱串联质谱(liquid chromatography tandem mass spectrometry,LC-MS/MS)技术检测CMT-9发酵液的主要组分,结合Illumina高通量测序解析CMT-9的全基因组信息,并将其与B.velezensis CMT-6、B.amyloliquefaciens DSM7T、B.velezensis FZB42和B.subtilis 168中脂肽合成相关的代谢通路和关键基因进行比较分析。结果表明,CMT-9的发酵液含有表面活性素、伊枯草菌素、芬荠素3种脂肽。全基因组测序分析发现,CMT-9菌株染色体的基因组全长为3928149 bp,G+C含量为43.39%,tRNA数量为83,rRNA为9。通过GO、KEGG、COG数据库比对,其差异基因主要富集在碳水化合物代谢和氨基酸代谢等合成脂肽的相关通路;脂肽谱相近的菌株CMT-9、CMT-6、FZB42在基因组组分、G+C含量、共线性、同源性和共有基因中均表现出高度的一致性。该研究通过LC-MS/MS和比较基因组学技术联用解析芽孢杆菌脂肽谱的差异及其分子机理,以期为脂肽高产菌株的筛选及基因库的构建提供理论基础。

The article aims to explore the molecular mechanism of antimicrobial lipopeptide by marine Bacillus amyloliquefaciens CMT-9.LC-MS/MS was used to detect the main components of CMT-9 fermentation broth,and whole genome information was analyzed by combining Illumina high-throughput sequencing,which were in comparison with the metabolic pathways and key genes related to lipopeptide synthesis in Bacillus velezensis CMT-6,Bacillus amyloliquefaciens DSM7T,Bacillus velezensis FZB42 and Bacillus subtilis 168.The results indicated that the primary components of fermentation broth of CMT-9 were Surfactin,Iturin and Fengycin.From the whole genome sequencing analysis,the genome length of the CMT-9 strain chromosome is 3928149 bp,with 43.39%G+C,83 tRNA and 9 rRNA.From GO,KEGG and COG databases,the differential genes mainly originated from the pathways associated with lipopeptide synthesis,such as carbohydrate metabolism and amino acid metabolism.High concordances were exhibited in genomic composition,content of G+C,colinearity,homology and shared genes between CMT-9,CMT-6 and FZB42 with similar lipopeptide spectrum.The differences of lipopeptide spectrum and the molecular mechanism in B.amyloliquefaciens were analyzed simultaneously via LC-MS/MS and comparative genomics,providing a theoretical basis for the screening of high-yielding lipopeptide strains and the construction of gene library.