枯草芽孢杆菌CS16抑菌活性与胞外产物成分分析

Analysis of Antimicrobial Activity and Extracellular Metabolites of Bacillus subtilis Strain CS16

通过测定枯草芽孢杆菌CS16菌株的抑菌活性,对其胞外代谢物活性与成分进行分析,以期开发有效的生防菌剂。结果表明:CS16菌株对多株植物病原真菌具有明显的抑制作用,对病原细菌的抑菌作用相对较弱;CS16发酵液中羧甲基纤维素酶、淀粉酶和木聚糖酶活力分别为509.58 U/mL、7 198.71 U/mL和1 853.68 U/mL;其发酵液经酸沉淀所得粗提物可明显抑制香蕉枯萎病菌丝生长,最小抑菌浓度为0.062 5 mg/mL;利用反相硅胶柱、Sephadex LH-20凝胶柱和正相硅胶柱分离纯化获得较纯的抑菌物质,经薄层层析和HPLC定性分析,初步认为其胞外抑菌物质中含有Iturin A。

In order to develop effective biocontrol agents, the antimicrobial activity and extracellular metabolites of Bacillus subtilis strain CS16 were analyzed. The results showed that strain CS16 had strong inhibition against many pathogenic fungi but rather weak in anti-bacterial activities.The activities of carboxymethyl cellulase, amylase and xylanase in fermented liquid of CS16 were 509.58 U/mL, 7198.71 U/mL and 1853.68 U/mL, respectively. The crude extract of the fermented liquid from strain CS16 had distinct inhibition against Fusarium oxysporum f.sp. cubense and its minimal inhibitory concentration（MIC）was 0.062 5 mg/mL. And then the extract was purified by reverse-phase silica gel column, sephadex LH-20 gel column and normal-phase silica gel column. The antimicrobial substance in the purified extract was Iturin A by thin-layer chromatography and HPLC analysis.