应用统计学方法优化L-乳酸发酵培养基

Statistical optimization of the fermentation medium for L-lactic acid fermentation

采用Plackett-Burman实验、最陡爬坡实验和响应面实验,对以马铃薯为主要原料发酵制备L-乳酸的培养基进行优化。通过Plackett-Burman实验筛选出对乳酸发酵影响显著的因子为马铃薯糖化液、酵母膏和硫酸锰,利用最陡爬坡实验逼近最大响应区,采用中心复合实验设计及响应面分析法进行回归分析,建立影响乳酸产量的二次模型。模型求解得出马铃薯糖化液、酵母膏、硫酸锰最优浓度分别为110.7、14.98、0.016 g/L时,最大乳酸产量达到94.09 g/L。在最优条件下进行验证实验,3次实验平均值为93.2 g/L,与预测值之间的误差为0.9%。与优化前相比,乳酸产量提高了11.2%,L-乳酸的纯度达到94.8%。

The fermentation medium for L-lactic acid fermentation was optimized by Plackett-Burman design,steepest climbing experimental design and response surface methodology.Plackett-Burman experimental design study of 8 factors in the medium fractions,the liquid of potato saccharification,yeast extract and manganese sulfate selected three significant factors,choose these three factors as the main subjects for further optimization work.Steepest ascent experiment factors determined the center of response surface experimental.Central composite design and response surface methodology were employed to investigate the interaction of the variables and to ascertain the optimal values of the factors,which finally led to the maximum lactic acid production.The theoretical optimal conditions were： the liquid of potato saccharification 110.7 g/L,yeast extract 14.98 g/L,manganese sulfate 0.016 g/L,the maximum lactic acid yield was 94.09 g/L.To verify the optimal experimental conditions,an average of three experiments 93.2 g/L,and the error value was 0.9% between the predicted.Compared with the former,lactic acid production increased 11.2%,L-lactic acid purity was 94.8%.