响应面法优化胶质芽孢杆菌GM1增殖发酵培养基

Application of response surface methodology to optimize the spore production of B.mucilaginosus GM1

在摇瓶培养条件下,优化提高胶质芽孢杆菌GM1菌体浓度的发酵培养基组分。在单因素的基础上选择糖蜜、复合氮源(硫酸氨与豆粕)以及初始pH为自变量,芽孢杆菌数为响应值,根据Box-Behnken实验设计原理以及Design Expert 8.0软件进行回归分析,确定了胶质芽孢杆菌GM1发酵培养基的最佳组成为:糖蜜3.2%、复合氮源0.4%,pH为8.0,在此条件下最大理论数值为3.03×108CFU.mL-1。经过3次平行实验验证,实际活菌体数为3.09×108CFU.mL-1,该实验值与预测值拟合较好。优化后的活菌浓度与优化前菌体浓度相比提高了40%,由此可知,响应面分析法优化微生物发酵条件是一种十分有效的方法。

Using shaking-flask fermentation in the laboratory to optimize the components of GM1 fermentation medium.On the basis of single experiments and according to the Box-Behnken experimental design principles,the response surface methodology was applied to optimize the three major factors for GM1 liquid-state fermentation.By solving the quadratic regression model equation,the optimal values of the variables were determined as：the molasses 3.24%,complex nitride 0.41%,pH7.91.Then the largest number of bacteria predicted by the theoretical model was 3.0293×108CFU·mL-1.With the optimum medium,the live bacteria number was 3.09×108CFU·mL-1,which increased nearly more than 40% contrasting on the initial culture medium.On the conclusion that response surface methodology was an available way to optimize the fermentation conditions.