中文摘要：

为了研究分离自催吐萝芙木的内生细菌Bacillus subtilis LYM3的抑菌谱及其产生的抑菌活性产物,利用对峙生长法测试了菌株LYM3对10种植物病原真菌的拮抗活性,利用Sephadex LH-20凝胶柱对其产生的抑菌活性产物进行了分离,并利用LCMS-IT-TOF进行了初步鉴定。结果显示：菌株LYM3对10种植物病原真菌均有较强的拮抗作用,抑制率均在60%以上,其中对香蕉炭疽病菌的抑菌活性最强,抑制率为83.5%;LYM3产生的抑菌物质主要为胞外产物,具有较好的热稳定性,在p H 6~12活性稳定;经分离发酵液获得3种抑菌活性组分A、B和C,经初步鉴定推测A属于伊枯草菌素,B和C属于表面活性素。可见,菌株LYM3具有广谱抗菌性,其产生的抑菌活性产物主要为脂肽类物质。

英文摘要：

In order to study the inhibition spectrum and antifungal products of an endophyte Bacillus subtilis LYM3 from Rauvolfia vomitoria Afzel,the antagonistic activity of strain LYM3 to 10 kinds of plant pathogenic fungi was tested using confrontation growth method,and the antifungal products were purified using Sephadex LH-20 and identified by LCMSIT-TOF. The results showed that strain LYM3 had obvious antagonistic activity to 10 kinds of plant pathogenic fungi,and the inhibition rates were all above 60%. Among them,strain LYM3 had the highest antagonistic activity to Collectorichum musae with the inhibition rate of 83. 5%. The antifungal products produced by strain LYM3 were mainly extracellular products,which had better thermal stability,being stable in p H 6-12. Three fractions A,B and C with antifungal activity were obtained from fermentation broth of LYM3. After preliminary analysis,it was speculated that A belonged to iturin,B and C belonged to surfactin. Strain LYM3 had broad-spectrum inhibition activity,and its antifungal products were mainly lipopeptides.