海洋细菌抗菌筛选及深海独岛枝芽胞杆菌A493活性物质分离鉴定

以水稻黄单胞菌等植物病原菌为指示菌,采用平板对峙法对411株海洋细菌进行了抗菌筛选,初筛获得具有抗菌活性的海洋菌株81株,复筛获得具有稳定抗菌活性的菌株7株,最后通过测定抗菌谱,得到1株抗菌谱特异并且稳定拮抗水稻黄单胞菌的深海独岛枝芽胞杆菌（Virgibacillus dokdonensis）A493.对水稻白叶枯病害的温室生防实验表明,经过A493无菌发酵上清波处理,水稻生长20 d后对水稻白叶枯病害的防治效果达到了66.7％,且对水稻的正常生长无不良影响.通过离子交换色谱法提取,再经2次薄层层析硅胶板回收分离,得到了纯化活性物质,经过ESI-MS＂分析,初步判断活性物质分子量为317 Da.Doskochilova系统纸层析结果显示活性物质很可能为新的氨基糖苷类物质.

Screening, Isolation and Identification of Deep-Sea Virgibacillus Dokdonensis A493 Antibacterial Substance

Xanthomonas oryzae pv. oryzae and other plant pathogens were used as indicating strains. In to- tal,411 marine strains were investigated by confront culture method in which about 81 marine strains showed potential antibacterial activities against plant pathogens. After re-screening based on stable antibacterial activi- ty,7 marine strains were selected and applied for antibacterial spectrum determination. By determining the anti- bacterial spectrum,we finally found Virgibacillus dokdonensis A493 from deep-sea that had specific antibacteri- al spectrum. Effect of aseptic fermentation supernatant of Virgibacillus dokdonensis A493 against rice leaf blight was measured in greenhouse and the result showed that 66.7~ of the plants were still healthy after trea- ted with aseptic fermentation supernatant for 20 days. The active compound showed no adverse effect on normal growth of rice. The active compound was purified by means of ion exchange chromatogramphy and thin-layer chromatogramphy,and then analyzed by ESI-MSn. Its molecular weight was determined around 317 Da after preliminary analysis of the fragmentation peaks appearing in the mass spectrum. Compared with different refer- ence standards by the eight-solvent system paper chromatography, this compound was most likely a novel.amin- oglycoside antibiotic.