枯草芽孢杆菌XZG-11抗菌蛋白对番茄青枯假单胞菌抗菌活性研究

Study on Antibacterial Activity of Antagonistic Protein from Bacillus subtilis XZG-11 Against Tomato Pseudomonas solanacearum E. F. Smith

为给菌株XZG-11粗提蛋白的应用提供理论依据,采用硫酸铵分级盐析法分离抗菌蛋白,通过抑菌圈测试法检测其对植物致病真菌和细菌的抑菌活性,并对其生物稳定性进行研究和分析。结果表明,粗提抗菌蛋白对番茄青枯病假单胞菌的抑制效果最强,同时对茄子早疫病菌、番茄灰霉病菌、西瓜枯萎病菌、赤霉菌、镰刀霉菌也具有较强的抑制作用;对革兰氏阳性菌如枯草芽孢杆菌、金黄色葡萄球菌、白色念珠菌均具有强烈的抑制作用,同时还对革兰氏阴性菌如大肠杆菌、绿脓假单胞菌也具有显著抑制作用。抗菌蛋白在pH5.0~11.0范围内较稳定;在80℃以下,热稳定性好,对RNA酶不敏感,对蛋白酶K和胰蛋白酶敏感。菌株XZG-11粗提抗菌蛋白具有较强的稳定性,对植物病原真菌和细菌具有广谱抗菌活性。

In order to provide a theoretical basis for the application of the antibacterial protein, the antibacterial protein was isolated from fermentation broth using ammonium sulfate fractionation and the antibacterial activity on plant pathogenic fungi and bacterium were investigated by the method of inhibition zone. The results indicated that the crude extracted protein produced by the stain XZG-11 had the strongest antibacterial activity to Pseudomonas solanacearum E. F. Smith. It also showed strong inhibitory activity against various plant pathogenic fungi, such as Alternari solani, Botrytis cinerea, Fusarium oxysporum f. sp. niveum, Fusarium sp. and Fusarium head blight. The gram-positive bacteria such as Bacillus subtilis, Candidal vaginitis and Staphylo-coccus aureus were strongly inhibited by the antifungal protein. Besides, the antifungal protein also exhibited inhibitory effect on gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa. This antifungal protein was relatively stable between pH5.0 and pH11.0 and below 80℃ . It was resistant to RNase but was sensitive to protease K and trypsinase. The antibacterial protein of Bacillus subtilis XZG-11 had the strong stability and the broad antimicrobial activity to plant pathogenic fungi and bacterium.