一株芦荟抗菌内生细菌的分离鉴定及生物学性质研究

Identification and characterization of an antimicrobial endophytic bacteria associated with Aloe chinensis(Haw.) Baker

从药用植物中华芦荟组织中分离出一株抗菌内生细菌A11#,该菌产生广谱抗菌活性物质,对金黄色葡萄球菌、枯草芽孢杆菌等革兰氏阳性细菌和植物病原真菌均有较强的抑制作用;通过形态学观察及生理生化特征测定,初步鉴定归属于芽孢杆菌属(Bacillus)。该菌在初始pH值为5.0～10.0的PDA培养基上生长旺盛,生长最适pH为5～7,培养液初始pH为6～10时发酵产生大量粘性物质;生长温度范围在10～45℃,最适温度28～37℃;在初始pH5.0和30.5℃条件下发酵,其发酵液抑菌作用最强;该菌所产抗菌物质能耐121℃处理30min而不影响其活性。在阿须贝无氮培养基上生长良好,在不加葡萄糖、蔗糖或淀粉的LB和牛肉膏蛋白胨培养基上不生长;同时还产生对高岭土有絮凝活性的物质。

An antimicrobial endophytic bacteria, designated A11#, was isolated from the interior of medicinal plant Aloe chinensis(Haw.) Baker, produces wide-spectrum antibacterial metabolites against the Gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis and phytopathogen. According to mensuration of physiological and biochemical characters and observation of morphological characters, the isolate is identified to be Bacillus sp.. The isolate blooms growth on the PDA medium with initial pH5.0～10.0 and produces volumes of viscosity substances incubated in the medium with initial pH6.0～10, and pH5.0～7.0 is optimal growth range; it's growth temperature range is from 10～45 ℃ and optimal growth temperature range is from 28～37℃; the fermenting liquid fermented under condition with initial pH5.0 and 30.5 ℃ has the most effect against microbe and has no activity losing at 121 ℃ for 30 min. It grows well on the non-nitrogen medium(Ashby medium) but can`t grow on the Luria Bertani medium(LB) and beef extract peptone medium without adding glucose, sucrose or starch, it also metabolizes the flocculant compounds which have flocculating activity to kaolin suspension.