In order to improve γ-aminobutyric acid production ability of Lactococcus raffinolactis,the fermentation conditions of γ-aminobutyric acid produced by Lactococcus raffinolactis Y-12 were optimized using response surface methodology.On the basis of single factor experiment results,a 3-factor,3-level Box-Behnken was designed,in which fermentation temperature,fermentation time and initial pH value were chosen as independent variables,and the yield of GABA as the response index.The result showed that the regression model fit well with experimental data,which can predict the yield of GABA well.The optimal fermentation conditions were determined as follow:inoculums dosage is 4％,fermentation temperature is 34℃,fermentation time is 73h and initial pH value is 6.0.Under the optimal conditions,the GABA yield is 4.06 g/L,compared with the theoretical value (2.29％),it has a small relative error which is only 2.29％.%为提高乳球菌产γ-氨基丁酸的能力,采用响应面法优化棉籽糖乳球菌Y-12产γ-氨基丁酸发酵条件.在单因素试验结果基础上,选择发酵温度、发酵时间和初始pH为自变量,以GABA产量为响应值,运用Box-Behnken法设计3因素3水平响应面设计.结果表明,响应面模型与实际情况拟合良好,能够较好预测GABA产量.获得最佳发酵条件为接种量4％、发酵温度34℃、发酵时间73h和初始pH 6.0,在此条件下GABA产量为4.06 g/L,与理论值(4.153 g/L)相比,相对误差仅为2.29％.
展开▼
