抑制黄瓜疫病生防菌株 LY-38的发酵条件优化

摘要

为了对防治黄瓜疫病的生防菌株 LY-38的产业化生产提供参考，通过单因子试验和正交试验，对培养基组分中最佳碳源、氮源和无机盐进行筛选，在确定适合该菌株的培养基组分基础上，对其培养条件进行优化。结果表明：适合枯草芽孢杆菌生防菌株 LY-38拮抗物质产生的最佳碳源为葡萄糖和玉米淀粉，最佳氮源为蛋白胨和黄豆粉，含量为葡萄糖1．0％、玉米淀粉0．5％、蛋白胨1．0％和黄豆粉2．0％；最佳无机盐为 MgSO4·7H2 O 和 CaCO3；最佳培养温度为32℃、培养时间为44 h、初始 pH 7．2、接种量为3．0％（体积分数）、转速为150 r／min。在优化后的培养基成分和培养条件下，LY-38菌株发酵滤液的拮抗圈直径可达21．2 mm，比基础培养基的拮抗圈直径提高41．3％。%To provide a reference for industrialized production of biocontrol strain LY-38,which could inhibit cucumber blight,a single factor test and an orthogonal test was conducted to screen the optimum carbon source, nitrogen source and inorganic salt, and the culture conditions were optimized after confirming the culture medium suitable for LY-38.Results:The best carbon source was glucose and corn flour,the best nitrogen source was peptone and soybean farina,containing 1.0% glucose,0.5% corn flour,1.0% peptone and 2.0% soybean meal;The best inorganic salts were MgSO4 ·7H 2 O and CaCO3;The optimum culture conditions included temperature 32℃,time 44 h,initial pH 7.2,inoculum size 3.0%(volume fraction),rotate speed 150 r/min.Under optimized culture medium components and culture conditions,the diameter of antagonistic zone from LY-38 fermentation filtrate could reach 21.2 mm, increased by 41.3% than that of initial medium before optimization.