产γ-氨基丁酸乳酸菌的发酵优化

Optimization of Fermentation Conditons forγ-Aminobutyric Acid-Producing Stain of Enterococcus lactic

为显著提高γ-氨基丁酸的产量,对发酵培养基的装液量、接种量、碳源、氮源、L-谷氨酸(L-Glu)的添加量进行了单因素优化,在单因素基础上进行响应面优化,利用Plackett-Burman得出对产γ-氨基丁酸影响最大的因素分别为:葡萄糖、玉米浆、接种量以及发酵时间,用最陡爬坡试验逼近关键因素的最大响应区域。在此基础上,采用Box-Behnken试验设计对培养基组分进行进一步优化,得出4种显著因子葡萄糖、玉米浆、接种量以及发酵时间的最佳结果分别为22.0g·L-1、15.0g·L-1、19%和48h。采用优化培养基后,γ-氨基丁酸的产量可达到12.030g·L-1,较原始培养基的产量增加了5.602g·L-1。

In order to significantly increase the yield ofγ-aminobutyric acid produced by Enterococcus lactic,the fermentation medium forγ-aminobutyric acid was optimized.Firstly,the single factors of the fermentation condition such as liquid volume in flask,inoculation amount,carbon source,nitrogen source,and L-glutamate(L-Glu)were determined.Then,on the basis of single factor,the biggest impact factors of the glucose,corn steep liquor,inoculation amount and the fermentation time were obtained by the response surface optimization and the key factors of maximum response area were gained by the steepest grade test.Finally,the key factors were further optimizied by the Box-Behnken experiment design.Four significant factors(glucose,corn steep liquor,inoculation amount and the fermentation time)were 22.0g·L-1,15.0g·L-1,19%,and 48 hrespectively.Under these conditions,the yield ofγ-aminobutyric acid could reach 12.030g·L-1,which increased5.602g·L-1 compared with the yield of the original medium.