基于PB设计和BBD响应面法优化高山被孢霉 产花生四烯酸发酵培养基

使用响应面法对高山被孢霉生产花生四烯酸(ARA)的发酵培养基成分进行优化。以摇瓶发酵7 d的ARA产量为指标,在前期试验的基础上,利用Plackett-Burman法设计试验考察酵母粉、葡萄糖、玉米浆干粉、磷酸二氢钾、硫酸镁和氯化钙6个因素的影响;分析筛选出葡萄糖、酵母粉和玉米浆干粉3个主要因素,再以最陡爬坡路径试验逼近最大响应区域,最后用Box-Behnken中心组合设计三因素三水平试验,利用Design Expert 10软件进行二次回归分析计算得到ARA产量最高的培养基,其成分为酵母粉12.6 g·L~(-1),葡萄糖75.6 g·L~(-1),玉米浆干粉7.1g·L~(-1),磷酸二氢钾1 g·L~(-1),硫酸镁0.5 g·L~(-1),氯化钙0.5 g·L~(-1),pH 6.5。在该条件下,ARA产量达到了5.12 g·L~(-1),与预测值的5.17g·L~(-1)接近,相比优化前的初始培养基,ARA产量提高了27.3%。该结果为提高ARA生产水平提供了研究基础。

Optimization of culture medium for arachidonic acid production by Mortiella alpina using PB design and BBD design response surface methodology

In this study, the response surface method was used to optimize the fermentation medium composition of arachidonic acid (ARA) produced by Mortierella alpina. Taken the 7-day ARA yield of fermentation as the index, the Plackett-Burman method was used to investigate the effects of six factors including yeast powder, glucose, dried corn steep liquor powder, potassium dihydrogen phosphate, magnesium sulfate and calcium chloride on the ARA yield based on previous experiments. After analyzing and screening out three main factors: yeast powder, glucose and dried corn steep liquor powder, the steepest climbing path experiment was used to approach the maximum response area. Finally, a three-factor and three-level experiment was designed by Box-Behnken center combination, and the highest yield of ARA was obtained using the Design Expert 10 software for quadratic regression analysis. The results showed that under the conditions of yeast powder 12.6 g·L^-1, glucose 75.6 g·L^-1, dried corn steep liquor powder 7.1 g·L^-1, KH₂PO₄ 1 g·L^-1, MgSO₄ 0.5 g·L^-1, CaCl₂ 0.5 g·L^-1 and pH 6.5, the ARA yield reached 5.12 g·L^-1, which was close to the predicted value of 5.17 g·L^-1, 27.3% higher than that before optimization. This experiment provides a research basis for improving the industrial production level of ARA.