雷蘑液态发酵工艺响应面法优化研究

在雷蘑（Clitocybe gigantean）AS 5.105液态发酵培养基优化的基础上，采用Plackett-Burman设计(Plackett-Burman Design，P-B)对影响雷蘑发酵胞外多糖的内在和外在因素进行了筛选，所选取的6个相关因素为：初始pH，培养温度，发酵时间，装液量，接种量，摇床转速。在此基础上，再采用响应曲面法(Response Surface Methodology，RSM)对影响雷蘑发酵胞外多糖的关键影响因素培养温度，发酵时间和装液量的最佳水平范围作了进一步的研究与探讨，通过对二次多项回归方程求解得知，在上述自变量分别为培养温度27.05℃、发酵时间6.92d和装液量93.90ml时，胞外多糖产量的最大预测值为103.58mg/100ml。

Optimization of Submerged Fermentation Conditions for Extracellular Polysaccharide by Clitocybe gigantean Using Response Surface Methodology

Our previous work has indicated that cultivation conditions for extracellular polysaccharide by Clitocybe gigantean are strongly affected by many internal and external factors. In this study，we use an effective two-phase statistical approach to enhance extracellular polysaccharide production. In the first phase，Plackett-Burman design was undertaken to evaluate the effects of the six factors，including initial pH，culture temperature, fermentation time，volume of medium，amount of inoculum and rotate speed. By regression analysis，culture temperature， time and amount of inoculum were found to be important for cultivation conditions for extracellular polysaccharide by Clitocybe gigantean. In the second phase of the optimization process，a response surface methodology(RSM) was used to optimize the above critical factors，and to find out the optimal concentration levels and the relationships between these factors. Based on the results of the first phase，a three-level three-factor(culture temperature， fermentation time and volume of medium) Box-Behnken design was employed. By solving the quadratic regression model equation using appropriate statistic methods，the optimal concentrations for obtain 103.58mg/100ml extracellular polysaccharide production was calculated as: culture temperature 27.05℃, fermentation time 6.92d and volume of medium93.90ml. The experimental data under various conditions have validated the theoretical values.