重组毕赤酵母产凝乳酶发酵参数优化的研究

以重组毕赤酵母GS115PJ5(含微小毛霉凝乳酶基因)为研究对象,通过单因素实验确定其最佳生长条件:培养温度30℃、培养基pH值5.2、摇床转速280r/min、培养基装瓶量5%(12.5mL/250mL)。在单因素实验的基础上通过Plackett-Burman实验筛选出培养基装瓶量、甲醇添加量、培养基pH值等3个影响重组毕赤酵母产凝乳酶的主要因素,并通过响应面实验确定三者有利于产酶的最佳值分别为13.06%、1.52%、6.15,在此条件下,凝乳酶活力达到最大值即491.7SU/mL,验证实验证明模型预测值准确、可靠。

Study on optimization of fermentation parameters for producing rennet by recombinant Pichia pastoris

The conditions for growth and production of recombinant Mucor pusillus rennet were investigated.The optimal growth condition was obtained by single factor experiments:temperature 30 ℃,pH 5.2,rotating speed 280 r/min,volume of medium 5%(12.5 mL/250 mL) .The optimal enzyme producing condition was studied by Plackett-Burman based on the single factor experiments.The most important factors were volume of medium,methanol concentration,pH of medium.Then,response surface methodology was used to optimize the above three factors,with the optimum value 13.06%,1.52%,6.15,respectively.The milk-clotting activity would reach the highest value(491.7 SU/mL) under the optimized fermentation conditions.The predicted values from the response surface methodology were proved to be correct and reliable by verification test.