海洋枯草芽孢杆菌3512A抗真菌脂肽的分离纯化及结构特性鉴定

Purification and Structural Identifications of the Antifungal Lipopeptides Produced by Marine Bacterium Bacillus subtilis 3512A

海洋枯草芽孢杆菌Bacillus subtilis菌株3512A分离自中国南海柳珊瑚。抗菌谱研究表明,该菌对多种动植物病原菌都有很强的抑制作用。稳定性试验表明该菌株产生的抗真菌活性物质对高温、酸和弱碱具有一定耐受性。利用玉米纹枯病菌Rhizoctonia solani作为靶标菌,结合酸沉淀、快速柱色谱、HPLC等现代色谱手段,对菌发酵液中的抗真菌活性物质进行分离纯化,获得两个活性强的单一化合物,化合物1和3。排油圈试验、甲苯乳化试验、TLC原位酸水解,以及一维核磁共振氢谱1H-NMR等多种研究结果表明,化合物1和化合物3均为脂肽类化合物衍生物。

Bacillus subtilis 3512A, a marine bacterium, was isolated from Pacifigorgia sp. in South China Sea. The strain showed significant antagonistic activities against many pathogens. The crude antifungal extract was stable against high temperature and acid, whereas the antifungal activity reduced notably when pH value is higher than 10. Bioassay-directed fractionation using acid precipitation, flash chromatography and HPLC led to the isolation and purification of two pure metabolites. Oil-film collaps- ing, emulsification of toluene and on-plate hydrolysis experiments showed the two compounds are cyclic peptides. ^1H-NMR experiment confirmed both of them were lipopeptide derivatives.