γ-聚谷氨酸发酵培养基的Plackett-Burman法优化

Optimization of Poly γ-glutamic Acid Fermentation Medium Using Plackett-Burman Experimental Design

以一株γ-聚谷氨酸高产菌——地衣芽孢杆菌GIM-P10为试验菌株,采用逐因子实验法确定γ-聚谷氨酸合成考察因素的参考范围,再采用Plackett-Burman设计法进行培养基的优化,10个实验因子中筛选到四个显著影响因子:柠檬酸、谷氨酸、K2HPO4和MgSO4·7H2O。另外,综合评价实验结果,表明γ-聚谷氨酸的产量与多糖含量呈负向关系,与细胞干重呈正向关系。利用Plackett-Burman设计法发酵产γ-聚谷氨酸可高达21.27g/L,为基础培养基的2倍以上。

A high productive poly γ-glutamic acid strain Bacillus licheniformis GIM-P10 screened by culturing in different mediums.Single-factor designs were used to determine the ranges of value of each related factor which may effect the production of γ-PGA.Then Plackett-Burman factorial design was carried out,to evaluate the effect of different cukure conditions on the production of PGA.Ten variables were examined for their significance on PGA production. Among those variables,citrate,MgSO4·7H2O,L-glutamate and K2HPO4 were found to be the most significant variables that encourage PGA production.The overall trend evaluation of the experimental results revealed a direct proportion between PGA and CDW on one side and the polysaccharide on the other.The optimal medium,based on statistical analysis,showed a production of 21.27g/LPGA,which is more than three times the basal medium.