响应面法优化酿酒酵母培养基的研究

目的]采用响应面法研究优化酿酒酵母培养基的条件。方法]在试验设计中，以KH2PO4、MgSO4和尿素为自变量，通过响应面回归分析和显著性检验，建立了乙醇产量的二次回归模型。再通过对乙醇产量的响应曲面分析，研究了3种无机离子对酿酒酵母发酵乙醇优化生产的最佳工艺条件。结果]由响应面分析结果可知，回归模型存在稳定点（-2．4278、6．505631、1．753767），稳定点的特征值表明稳定点为最大值点，即KH：P0。为0．2861g／L、MgSO。为0．97528155g／L和尿素为5．8768835g／L时，乙醇产量为123．9997g／L。采用上述优化的工艺条件进行的固定化酵母发酵试验表明，3次重复测得的乙醇产量的平均值为122．6074g／L，说明实际试验值与模型预测值基本一致。结论]在酵母发酵生产过程中，向其培养基中添加KH2PO4 0．2861g／L、MgSO4 0．97528155g／L和尿素5．8768835g／L时，能使乙醇产量达到最佳值。

Study on Optimization of Ethanol Fermentation Medium by Using Response Surface Method

Objective ] The study aimed to research the conditions of optimizing the ethanol fermentation medium by using response surface method. Method] n the test design, with KH2PO4, MgSO4 and the urea as the independent variables, the quadratic regression model for the ethanol yield was established through the response surface regression analysis and the significance examination, the best technological conditions of 3 kind of inorganic ions on the ethanol fermentation optimization production with yeast through the analysis on the response surface of the ethyl alcohol output. Result ] The results of the analysis by the response surface method showed that there was a stable point （ -2. 427 8, 6. 505 631,1. 753 767 ） in the regression model. As the eigenvalues of the stable point showed that the stable point was the maximum value, i. e. , when KH2PO4 was 0. 286 1 g/L, MgSO4 0 was 0. 975 281 55 g/L and urea was 5. 876 883 5 g/L, the ethanol yield was 123. 999 7 g/L. The immobilized yeast test by using the above optimized process conditions showed that the measurements of mean ethanol yield was as 122.607 4 g/L through 3 times of repeat tests, indicating that the actual test values were basically consistent with the forecast values. Conclusion ] In the yeast fermentation process, when 0. 286 1 g/L KH2PO4,0. 975 281 55 g/L MgSO4 and 5. 876 883 5 g/L urea were added into the medium, the ethanol yield could achieve the best value.