解淀粉芽孢杆菌ASR-12粗蛋白对多种植物病菌的抑制作用

为探究解淀粉芽孢杆菌ASR-12可能存在的拮抗作用机制，采用硫酸铵沉淀法从生防菌ASR-12发酵液中提取粗蛋白，以软腐病原菌作指示菌，测定其理化性质，并采用牛津杯法检测粗蛋白对8种病原真菌的抑制作用，同时以小麦雪腐病原菌作指示菌观察粗蛋白对病原菌的抑制作用。结果表明，该抗菌蛋白耐高温、耐紫外，最适pH值为7.0，对蛋白酶K和胰蛋白酶不敏感；它同时可以抑制大白菜软腐病菌和8种病原真菌；可抑制孢子萌发，降解菌丝细胞壁，造成菌丝畸形、膨大、扭曲。表明解淀粉芽孢杆菌ASR-12可产生至少一种理化性质稳定的抗菌蛋白，来有效地抑制多种植物病原菌。

The inhibitory effect of crude protein from Bacillus amyloliquefaciens ASR-12 against various plant pathogens

In order to study a possible antagonistic mechanism of Bacillus amyloliquefaciens ASR-12, the crude protein was extracted from fermentation liquid of biocontrol agent ASR-12 by ammonium sulfate precipitation method, and its physical and chemical properties were explored using pathogen of soft rot disease as indicator. The inhibitory effect of the crude protein on 8 species of fungal pathogens was detected by plate confrontation method. At the same time, the inhibitory effect of the crude protein on pathogen was observed using Typhula incarnata as indicator. The results showed that the antimicrobial protein was resistant to high temperature and ultraviolet, its optimum pH value is 7, and it is insensitive to protease K and trypsin. The antimicrobial protein can simultaneously inhibit the pathogen of Chinese cabbage soft rot and 8 species of fungal pathogens. It can inhibit spore germination and degrade mycelium cell wall, causing mycelial malformation, enlargement and distortion. In conclusion Bacillus amyloliquefaciens ASR-12 could produce at least one antimicrobial protein with stable physical and chemical properties, which could effectively inhibit various pathogens.