响应面法优化微生物油脂发酵条件

Optimization of fermentation conditions of microbial lipid by response surface methodology

利用响应面分析法对健强地霉G9菌株生产微生物油脂的发酵条件进行优化。通过Plackett-Burman设计法,对影响菌株油脂产量的8个因素进行考察,确定温度、KH2PO4添加量和花生饼粉添加量为对油脂产量有显著影响的3个重要因素。采用响应面法对3个重要因素的最佳水平进行优化,结果表明菌株最佳产油条件为:温度28℃,KH2PO4添加量16 g/L,花生饼粉添加量16 g/L。在此条件下进行摇瓶培养,健强地霉G9菌株油脂产量达10.73 g/L。采用优化的摇瓶实验条件进行5 L罐上发酵培养,菌株油脂产量达28.63 g/L,为摇瓶培养时的2.67倍,说明该优化条件也适用于5 L发酵罐生产,且健强地霉G9菌株适合放大生产,具有作为工业微生物生产菌种的潜力。

Eight factors influencing the lipid yield of Geotrichum robustum G9 strain were studied by Plackett- Burman design, and temperature, KHzPO4 and peanut cake were determined as the main factors. Response surface methodology （RSM） was employed to optimize the fermentation conditions of microbial lipid production by Geotrichum robustum G9 strain. The results showed that the optimal fermentation conditions were as follows ：temperature 28 ℃, KH2PO4 dosage 16 g/L and peanut cake dos- age 16 g/L. Under the optimal conditions, the lipid yield of Geotrichum robustum G9 strain reached 28.63 g/L after being cultured in 5 L fermenter which was 2.67 times as high as that cultured in flask （10.73 g/L）. The results indicated that the optimal conditions were also suitable for lipid production of Geotrichum robustum G9 strain in 5 L fermenter, and Geotrichum robustum G9 strain was suitable for scale - up production ,which had the potential to be applied as an industrial strain.