枯草芽孢杆菌B47菌株高产抗菌物质的培养基及发酵条件优化

Optimization of culture medium and fermentation conditions for high production of antimicrobial substance by Bacillus subtilis strain B47

摘要:

枯草芽孢杆菌Bacillus subtilis B47菌株为番茄内生细菌, 也是玉米小斑病拮抗菌, 能产生对玉米小斑病菌有强烈抑制作用的抗菌物质。以B47菌株发酵液的无菌滤液对玉米小斑病菌的抗菌活性为检测指标, 测定B47菌株产抗菌物质培养所需的最佳碳、氮源和无机盐, 并通过正交试验法对该菌株产抗菌物质的培养基配方和摇瓶发酵条件进行优化。研究结果表明, B47菌株产抗菌物质最佳碳、氮源和无机盐分别为蔗糖、酵母浸膏和MgSO4·7H2O, 最优培养基是YSB (Yeast extract-sucrose-beef extract)培养基, 其配方为: 蔗糖2%, 酵母浸膏2%, 牛肉浸膏1.5%, MgSO4?7H2O 0.06%, FeSO4·7H2O 0.000 9%, 最优发酵条件组合为: 30 °C, pH 7.0, 170 r/min摇床培养6 d, 接种量为1%, 装液量为40 mL/200 mL。

Abstract:

Bacillus subtilis strain B47 is an endophytic bacterium of tomato and can produce substance to inhibit the growth of Bipolaris maydis which can cause southern corn leaf blight. The optimal nitrogen source, carbon source and salt for the production of antimicrobial substance by strain B47 were tested. The medium composition and fermentation conditions were optimized by orthogonal experiments. The results showed that the optimal nitrogen source, carbon source and salt were yeast extract, sucrose and MgSO4·7H2O, respectively. The best medium was YSB (Yeast extract-sucrose-beef extract). The composition of the medium was 2% (W/V) sucrose, 2% (W/V) yeast extract, 1.5% (W/V) beef extract, 0.06% (W/V) MgSO4?7H2O and 0.000 9% (W/V) FeSO4·7H2O. The optimal fermentation conditions were the combination of temperature 30 °C, initial pH 7.0, incubation time 6 d, 1% inoculum volume percentage and medium volume 40 mL/200 mL.