生防菌解淀粉芽胞杆菌JT84发酵工艺优化

Optimization of fermentation process of biocontrol agent Bacillus amyloliquefaciens JT84

为探明解淀粉芽胞杆菌菌株JT84的使用前景,对其发酵工艺进行了研究。通过单因素试验和Plackett-Burman试验设计及Box-Behnken试验设计的响应曲面法,对JT84菌株的发酵培养基和培养条件进行了优化。确定培养基3个主要因子的质量浓度分别为:葡萄糖3.59 g/L、大豆蛋白胨21.89 g/L和K_2HPO_4 0.49 g/L;培养条件3个主要因子为:培养温度、装液量和发酵时间,根据响应曲面方程预测结果并结合生产实际,这3个主要培养条件因子分别设定为30.6℃、68 ml(250 ml三角瓶)和65.5 h。在初始pH为6.7、转速180 r/min、接种量3%的条件下,发酵液芽胞含量为1.67×10~9CFU/ml,较基础培养基(YPG)芽胞含量提高159%,无菌滤液对稻瘟病菌的抑菌带宽增加18.2%。

The single factor test,Plackett-Burman experiments and Box-Behnken response surface methodology were adopted to optimize the liquid fermentation medium and conditions of Bacillus amyloliquefaciens JT84 for application.According to the evaluation by the response surface model established in this study,the optimum mass concentrations of the three components,glucose,soya peptone and K_2HPO_4,in fermentation medium were 3. 59 g/L,21. 89 g/L and 0. 49 g/L respectively. The fermentation condition determination tests indicated that temperature,filling volume and shaking time were the major factors affecting JT84 yield. The optimized fermentation conditions were 30. 7 ℃,the filling volume 68 ml in 250 ml,shaking flask for 65. 5 h,at 180 r/min,and initial p H 6. 7 and inoculum volume 3%. Under the conditions spore production was up to 1.67×10~9CFU/ml,spore increased by 159% and the width of antifungal activity increased by 18. 2%compared with the basal medium（ YPG）.