产抗大肠杆菌脂肽化合物枯草芽孢杆菌筛选及脂肽化合物的分离纯化

Screening of Bacillus subtilis with Lipopeptide Compounds against E. coli and Purification and Separation of Compounds

采用致病性大肠杆菌作为主要指示菌,运用杯碟法对不同分离株的枯草芽孢杆菌代谢产物进行抑菌效果筛选。在确定GD株作为抗菌物质研究的基础上,采用GD株发酵液,经大孔吸附树脂XD吸附、洗脱,将获取的抗菌产物样品与表面活性素标准品进行薄层色谱(TLC)层析、分析、比较。运用液质联用(LC-MS)分析技术对代谢产物样品中各组分的含量、分子量及结构进行分析。结果显示:GD株在发酵过程中产生的抗菌物质是以表面活性素A、B和C等同系物为主组成的脂肽混合物。表面活性剂含量达77.39%,分子量主要分布在1 036.6933~994.6449之间。

The Bacillus subtilis strains capable of producing antibacterial lipopeptide were selected by cylinder-plate method, with the pathogenic Escherichia coli as the main indicator. According to the experimental results, on the basis of determining the isolate(GD) as an antimicrobial substance, using the fermentation broth of GD strain. After fermentation broth of GD strain adsorbed and eluted by macroporous resin XD in the study, products obtained above and standards of surfactin was carried out by thin layer chromatography(TLC) analysis and comparison, antibacterial substances in GD strain metabolites was proved as cyclic lipopeptide compounds surfactin;and through analysis of content, molecule and structure of metabolites by means of liquid chromatography and mass spectroscopy(LC-MS).The results showed that the antimicrobial substance produced by GD strain during fermentation was A mixture of lipopeptide mainly composed of homolog A, B and C. Surfactin content reached 77.39%, and the molecular weight was mainly distributed between 1 036.6933 to 994.6449.