蜡质芽孢杆菌AR156发酵培养基及发酵条件的优化

对前期筛选得到的在田间试验中防治根结线虫效果较好的蜡质芽孢杆菌(Bacillus cereus)AR156,通过单因素筛选及正交试验的方法进行了发酵培养基优化,得到的最佳配比为:麦芽糖0.25%,玉米粉0.5%,黄豆粉0.5%,胰蛋白胨0.5%,CaCl2·2H2O0.05%,MnSO4·H2O0.05%,K2HPO40.1%。同时对实验室摇瓶条件下液体发酵的主要影响因子温度、转速、初始pH值等进行实验探讨,确定了最佳培养条件:初始pH值7.0,装液量200mL/L,接种量5%,发酵温度28℃,转速200r/min,发酵时间48h。优化后芽孢产量为1.03×109CFU/mL,芽孢生成率在97%以上,明显高于初始发酵培养基发酵结果。

Optimization of Medium Components and Cultural Conditions of Bacillus cereus AR156

The single factor experiments and orthogonal experiments were adopted to optimize the liquid fermentation medium and conditions of the biocontrol agent of Bacillus cereus AR156. The results indicated that the constituents of medium, the filling volume of shaking flask, the rotation speed and the temperature were the major factors that affect the yield of AR156. The composition of maltose 0.25%, maizena 0.5%, soybean flour 0.5%, tryptone 0.5%, CaCl2·2H2O 0.05%, MnSO4·H2O 0.05% and K2HPO4 0.1% were selected to be the medium formula, and the fermentation conditions were the filling volume 200 mL in 1L shaking flask, inoculum 5%, 28°C, shaking at 200 r/min for 48 h, and initial pH at 7.0. Under the optimized fermentation conditions the production of spores was up to 1.03 × 109 CFU/mL, and the rate of spores was more than 97%.