Abstract: Bacillus subtilis A30 showed strong antagonistic activities to several fungal pathogens, e.g. Rhizoctonia solani, Magnaporthe grisea, etc. in vitro. A30 culture showed good control efficiency to rice sheath blight in the field. An antagonistic substance produced by A30 was purified by ammonium sulphate precipitation, FPLC and HPLC and named P1. P1 was both thermostable and proteinases stable. Its ninhydrin reaction was negative, but after acid hydrolysis, its ninhydrin reaction and biuret reaction were positive. Its molecular weight was primarily determined as 1476.7 Da according to the LC-ESI-MS analysis.

Key words: Bacillus subtilis, antagonistic peptide, purification, property, fungicide, Rhizoctonia solani

摘要： 平皿测试表明Bacillus subtilis A30菌株对多种植物病原真菌，例如水稻纹枯病菌(Rhizoctonia solani)、稻瘟病菌（Magnaporthe grisea）等有强烈抑制作用。在小区试验中A30菌液对水稻纹枯病也表现出了较好的防治效果。A30菌株培养液经硫酸铵沉淀、FPLC疏水色谱、HPLC反相色谱后，纯化得到一种拮抗活性物质，命名为P1。P1对热稳定，对蛋白酶不敏感；茚三酮反应呈阴性，用酸水解后茚三酮反应和双缩脲反应呈阳性。经LC-ESI-MS分析初步判断P1的分子量为1476.7 Da。

关键词: 枯草芽孢杆菌, 拮抗肽, 纯化, 性质, 杀真菌剂, 水稻纹枯病菌