重离子诱变酵母培养基的优化与研究

Optimization of Culture Medium for Heavy-ion Irradiation Bread Yeast Design

利用12C6+离子诱变技术对面包酵母菌种进行诱变,得到一株粗蛋白含量达到55%以上的菌株,借助Minitab16.0,采用Plackett-Burman实验设计法及响应面分析法,对诱变后面包酵母菌发酵培养基的成分进行了优化,得到3个最为显著的主要影响因子:葡萄糖、酵母抽提物和硫酸镁。利用最陡爬坡实验逼近最大响应区域后,利用Box-Behnken实验设计及响应面分析法进行回归分析。通过求解回归方程,得到优化发酵的条件为,葡萄糖:11.03 g/L、酵母抽提物:6.53 g/L、硫酸镁:5.59 g/L。面包酵母生物量为4.84 g/L,相比未进行优化时的生物量提高了15%。

A mutant bread yeast strain with high protein content of 55% was gained by use of 12C6＋ ions. The MINITAB 16.0 software, Plackett-Burman experimental design and response surface methodology were applied to opti- mize the culture medium for the irradiated yeast. The most important three factors which influenced the culture results were identified as glucose, magnesium sulphate and yeast extract. The path of the steepest ascent was undertaken to approach the optimal region of the three significant factors. Box-Behnken design and response surface methodology were used for the regression analysis. Finally, the optimal fermentation conditions were identified as glucose 11.03 g/L, yeast extract 6.53 g/L and magnesium sulphate 5.59 g/L by the regression analysis. It was found that the biomass of the bread yeasts reached 4.84 g/L and increased by 15% compared to original conditions.