响应面法优化黄色短杆菌c-11产L-丝氨酸发酵培养基

【目的】利用响应面法对黄色短杆菌c-11发酵培养基进行优化,以提高L-丝氨酸产率。【方法】先采用Plackett-Burman实验法对发酵培养基8个因素(蔗糖、酵母膏、硫酸铵、KH2PO4、MgSO4、生物素、VB1和碳酸钙)的效应进行评价,筛选出主要因素。之后采用最陡爬坡试验逼近主要因素(蔗糖、酵母膏和硫酸铵)的最大响应区域。在此基础上,采用Box-Behnken结合响应面法(RSM)确定主要因素的最佳水平,并通过二次方程回归分析。【结果】蔗糖浓度为83 g/L、酵母膏浓度为31 g/L和硫酸铵浓度为29 g/L时,此时模型稳定点预测值L-丝氨酸产量为22.27 g/L,验证值为22.65 g/L,预测值与验证值之间吻合较好。【结论】优化后的发酵培养基使c-11菌株的L-丝氨酸产量提高了28.11%。

Optimization of Fermentation Medium for L-serine Production by Brevibacterium flavum by Using Response Surface Methodology

【Objective】 The purpose of this paper was mainly to study the optimizing medium of Brevibacterium flavum in order to improve the production of L-serine.【Method】Firstly,the influences of eight related factors were evaluated in fermentation medium by Plackett-Burman design to filter out the main factors.The eight related factors were sucrose,yeast extract,(NH4)2SO4,KH2PO4,MgSO4,biotin,VB1 and CaCO3.The results showed that sucrose,yeast extract and(NH4)2SO4 were the main affecting factors.Secondly,the experimental design of steepest ascent was used to approach the best fermentation condition of main factors― sucrose,yeast extract,(NH4)2SO4.Based on this result,a three-level three-factor central composite design was employed to determine the maximum L-serine production at optimum concentration of sucrose,yeast extract and(NH4)2SO4.The L-serine production was found to correlate to the three parameters that could be represented by second-order polynomial models.【Result】 The optimal values of the three parameters were determined as 83 g/L sucroes,31 g/L yeast extract and 29 g/L(NH4)2SO4.The L-serine production was 22.27 g/L.In theory,the actual experimental result was 22.65 g/L.They were in well agreement.【Conclusion】 The production of L-serine was increased by 28.11% in optimized fermentation medium.