高产S-腺苷蛋氨酸的酿酒酵母发酵条件的响应面法优化

摘要

Design Expert software combining with the Plackett-Burman(PB) design and response surface methodology were applied to optimize the SAM production of S. cerevisiae. The PB results indicated that the inoculum volume, the concentration of L-Met and the fermentation time were three significant factors. And then the pass of steepest ascent, Box-Benhken design and response surface analysis were adopted to determine the optimize levels of the significant factors. The optimal fermentation conditions were inoculum volume 10% and concentration of L-Met 4. 0 g/L and cultivated at 30 ℃ for 56 h and the initial pH 6. 0 and 60 mL medium in 250 mL flask and the yeasts age 24 h and the agitation speed was 180 r/min. Under this fermentation conditions, SAM productivity was 287. 615 7 mg/g.%利用Design Expert软件,采用Plackett-Burman(PB)设计和响应面法(RSM)对产S-腺苷蛋氨酸(SAM)的酵母菌株的发酵条件进行优化,PB实验设计及分析结果表明,接种量、L-Met质量浓度、发酵时间是影响SAM胞内产量的3个显著因素.在此基础上通过最陡爬坡实验逼近最大响应区域,并采用Box-Behnken实验设计及响应面分析确定了发酵产SAM的最佳条件为接种量10％,L-Met质量浓度为4.0 g/L,发酵时间56 h,发酵温度30℃,pH为6.0,在250 mL三角瓶中装液量60 mL,种龄24 h,摇床转速180 r/min.最终优化后的SAM胞内产量达到287.615 7 mg/g,比初始产量提高1.38倍.