防腹泻布拉酵母培养条件的响应面法优化

Optimization of Cultivation Conditions of Saccharomyces boulardii Against Diarrhea Using Response Surface Method

在摇瓶水平上对布拉酵母(Saccharomyces boulardii)培养基及培养条件进行优化。先通过单因子法筛选最优碳源、氮源及无机盐,再利用响应面法优化发酵培养基组分及培养条件,采用Plackett-Burman法筛选影响布拉酵母生长的主要因素,用最陡爬坡试验及Box-Benhnken设计进一步优化选定的主要因素。得出最佳发酵培养基为:麦芽糖2%,蛋白胨2%,酵母浸提取物2.08%,培养基初始pH值为6;最佳发酵条件为:温度29.6℃,转速250 r/min,250 mL三角瓶培养基装量29 mL,接种量为5%,培养时间为24 h。优化后的布拉酵母菌体湿重达到32.2 g/L,比优化前(20.9 g/L)提高了54.1%;优化后活菌数达8.3×108CFU/mL,比优化前(5.5×108CFU/mL)提高了50.9%。

The fermentation medium and conditions of Saccharomyces boulardii were optimized based on single-factor experiments and response surface method.Single-factor experiments were performed to select the optimal carbon source,nitrogen source and inorganic salt.Response surface method was used to optimize the fermentation medium and conditions.A Plackett-Burman design was used to evaluate the effects of eight factors;the path of steepest ascent and the Box-Behnken design were performed for further optimization.The optimal fermentation medium contained 2% of maltose,2.08% of yeast extract,2% of glucose,with initial pH value of 6.0.The optimal fermentation conditions were as follows ：5% inoculums added to 250 mL erlenmeyer flask with 29 mL medium volume were cultured with shaking speed 250 r/min at 29.6℃ for 24 h.In the optimal fermentation medium and conditions,the cell wet weight of Saccharomyces boulardii increased from 20.9 g/L to 32.2 g/L,increased by 54.1%,the number of viable yeast increased from 5.5×108CFU/mL to 8.3 ×108CFU/mL,increased by 50.9%.