红树内生细菌CⅢ-1菌株鉴定及其胞外抗菌蛋白性质研究

Identification of Endophytic Bacterium CIII-1 Strain from Mangrove and Isolation of its Antimicrobial Proteins

摘要:

用对峙生长法从422株红树内生细菌中筛选到1株对青枯雷尔氏菌(Ralstonia solanacearum)、金黄色葡萄球菌(Staphylococcus aureus)、溶藻弧菌(Vibrio alginolyticus)、辣椒疫霉菌(Phytophthora capsici)、香蕉枯萎病菌(Fusarium oxysporum f. sp. cubense)等动植物病原细菌和真菌均具有较强的拮抗作用的海洋细菌CⅢ-1菌株, 经形态和生理生化特性及16S rRNA序列分析, 鉴定该菌株为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。用33%硫酸铵从菌株的培养滤液中盐析获得对供试病原菌均具有较强拮抗作用的抗菌活性蛋白, 性质测定发现, 该抗菌活性蛋白对热不稳定, 60?C和100?C下处理10 min, 其抗菌活性分别下降了62.5%和完全丧失, 在pH 5.0?10.0范围内均具有抑菌作用, 以pH 7.0时抗菌活性最强。

Abstract:

The CⅢ-1 strain, a marine bacterium screened out from 422 endophytic bacteria isolated from mangroves by the method of plate test, strongly inhibited the growth of Ralstonia solanacearum, Staphylococcus aureus, Vibrio alginolyticus, Phytophthora capsici, Fusarium oxysporum f. sp. cubense, etc. It was identified as Bacillus amyloliquefaciens based on the characters of morphology, physiology and biochemistry and 16S rRNA. Antimicrobial protein which produced by CIII-1 was the main antibacterial substance. The crude protein in culture filtrate could be precipitated with 33% ammonium sulfate and obtained by dialysis of the precipitate. The protein was found to be thermal-unstable, when treated at 60?C and 100?C for 10 minutes, its inhibitive activity would lost 62.5% and 100% respectively. The inhibitory activity of the protein was observed in the range of pH value from 5.0 to 10.0, and the strongest one was at pH 7.0.