枯草芽孢杆菌RSS-1菌株产生抗菌物质条件的优化

为明确枯草芽孢杆菌RSS-1菌株产生抗菌物质的最佳条件,提高其抗菌活性物质的产量,以发酵液抑制油菜菌核病菌(Sclerotinia sclerotiorum)活性为指标,在摇瓶条件下采用单因素和正交实验对该菌株的最适发酵培养基成分及发酵条件进行了优化。结果表明,菌株RSS-1产生抗菌物质的最佳培养基组分比例为2.0%的玉米淀粉,1.5%的蛋白胨,0.05%的MgSO_4;最佳发酵条件为培养基初始pH 6.0,培养温度为28℃,培养时间为5天,100 mL三角瓶装液量25 mL,接种量为0.1%,转速为180 r/min。优化后的枯草芽孢杆菌RSS-1菌株的无菌培养滤液对油菜菌核病菌的抑菌活性显著增强。

Condition Optimization for Antibiotic Substances Produced by Bacillus subtilis Strain RSS-1

To determine the best condition for Bacillus subtilis strain RSS-1 to produce antibiotic substances, and increase the yield of antifungal active substance, the fermentation liquid inhibition for the activity of Sclerotinia sclerotiorum was used as index, the single factor experiment and orthogonal experiment were adopted to optimize the optimal fermentation medium composition and fermentation condition under the condition of shaking flask culture. The results showed that the optimum medium composition was cornflour 2.0% (W/V), tryptone 1.5% (W/V) and MgSO4·7H2O 0.05% (W/V). The optimal fermentation condition was the combination of initial pH value 6.0, culture temperature 28°C, fermentation time 5 d, medium capacity 25 mL/100 mL, inoculum volume 0.1%, and the rotate speed 180 r/min. The inhibitory activity of B. subtilis strain RSS-1 fermentation filtrate increased significantly after the optimization of medium composition and fermentation condition.