枯草芽胞杆菌GB519抗菌蛋白的理化性质及生防效果

Physicochemical Characteristics and Biocontrol Efficacy of Antagonistic Protein from Bacillus subtilis GB519

枯草芽胞杆菌GB519是从土壤中分离对稻瘟病菌具有显著抑菌活性的菌株。为了明确菌株GB519抗菌粗蛋白的理化性质,分析了光照、紫外线、温度、pH和酶(蛋白酶K、胰蛋白酶和胃蛋白酶)对抑菌活性的影响。结果表明,抗菌蛋白对光照、紫外线和3种酶作用稳定;40℃~100℃处理1 h抑菌活性稳定,121℃处理30 min活性仅降低了7.4%,具有较好的耐高温特性;在pH 2.0~10.0活性稳定,但pH 11.0~12.0活性有所下降,分别降低了14.9%和18.1%。抗菌蛋白对多种植物病原菌具有抑菌作用,其中对茄子菌核病菌的抑菌活性为72.7%。在温室条件下对水稻叶瘟的防效达到80.1%。因此,菌株GB519可作为防控稻瘟病生防潜力菌进行开发。

The strain GB519 of Bacillus subtilis was isolated from the soil and showed significant antimicrobial activity against rice blast caused by Magnaporthe oryzae.In order to clarify the physicochemical characteristics of antagonistic crude protein of strain GB519,the effects of illumination,UV,temperature,pH and enzymes(proteinase K,trypsase and pepsase)on antimicrobial activity were analyzed.The results showed that antagonistic protein was stable in illumination,UV and three kinds of enzymes;Antimicrobial activity remained stable at 40―100℃for 1 h and decreased by only 7.4% at 121℃ for 30 min,showing good resistance to high temperature;Antimicrobial activity remained stable from pH 2.0 to 10.0,and declined by 14.9%and 18.1%at pH 11.0 and pH 12.0,respectively.Antagonistic protein had antagonistic effect on multiple crop pathogens,especially among which the antimicrobial activity against Sclerotinia sclerotiorum was 72.7%.Under greenhouse conditions,the biocontrol efficacy against leaf blast reached 80.1%.Therefore,the B.subtilis GB519 could be developed as biocontrol potential bacteria for the control of rice blast.