响应面法优化高山被孢霉产花生四烯酸的合成培养基研究

[目的]对高山被孢霉利用合成培养基液体发酵产花生四烯酸(ARA)的发酵液组分进行优化。[方法]对培养基中的碳源进行了优化,对单一碳源、复合碳源进行筛选,并优化了它们的起始浓度。利用单因素试验对多种无机氮源进行了筛选。对具有显著效应的葡萄糖、甘油、酵母粉和氨基酸混合物4个因素进行最陡爬坡试验后,利用响应面中心组合设计对显著因素进行了优化。[结果]最佳碳源组合为葡萄糖80 g/L+甘油20 g/L。以酵母粉为氮源,以氨基酸混合物为生长因子添加到培养基中,可促进高山被孢霉发酵液中ARA的积累。最佳合成培养基组分为:葡萄糖80 g/L,甘油12 g/L,酵母粉20 g/L,氨基酸混合物0.3 g/L。对优化后的合成培养基进行了验证,摇瓶发酵培养7 d后检测其产量,测得平均产量为7.084 1 g/L,与预测值接近。[结论]该研究结果可为进一步提高ARA在工业化生产中的得率提供研究基础。

Study on the Optimization of Synthetic Culture Medium for Producing Arachidonic Acid with Mortierella alpina by Using Response Surface Methodology

[Objective] To study and optimize the ingredients of fermented liquid for synthetic culture medium for producing arachidonic acid with Mortierella alpine and increase the yield of ARA.[Method] The carbon sources in the culture medium were optimized,single carbon source and composite carbon source were screened and their initial concentrations were optimized.Many kinds of inorganic nitrogen sources were screened out by using single factor test.After steepest ascent test on four significant factors(glucose,glycerol,yeast powder and amino acid mixture)with significant effects,significant factors were optimized by using response surface center combination design.[Result] The optimum carbon source combination was 80 g/L glucose + 20 g/L glycerol.Taking yeast powder as nitrogen source,amino acid mixture added in the culture medium as a growth factor could promote the accumulation of ARA in the fermentation liquid of M.alpine.The optimized synthetic medium was composed of 80 g/L glucose,12 g/L glycerol,20 g/L yeast powder and 0.3 g/L amino acid mixture.The optimized synthetic medium was verified and the yield was detected after shake flask fermentation culture 7 days.The average yield of ARA was 7.084 1 g/L,which was close to the predicted value.[Conclusion] The research results can provide research basis for improving the yield of ARA in the industrial production of ARA further.