利用响应面方法优化产L-乳酸的合成培养基

摘要

Response surface methodology was used to optimize the defined medium for lactic acid production by Lactobaciiius paracasei. The influence of eight kind of nutrients including amino acid mixture, nucleosides, vitamins on the cell growth and lactic acid production were investigated by the method of Plackett-Burman, identifying three significant components, that is amino acid mixture, KH2PO4 and CaCO3. The methodology of steepest ascent path was applied to approach the optimal region of the three significant factors. Box-Behnken design and response surface analysis were used to further investigate the optimal central level and the relationship of these factors. The mean value of lactic acid production in three verification experiments was consistent with the predicted value and more than the value in the complex medium. Ail these results provided a basis for metabolic flux analysis in L.paracasei.%采用响应面方法对拟干酪乳杆菌Lactobacillus paracasei (L.paracasei)的一种产乳酸的合成培养基进行了优化.该文将培养基中的混合氨基酸、核苷类物质和混合维生素看作3大类营养成分.首先利用Plackett-Burman实验设计考察了培养基中包括该3类营养物质在内的8种营养成分对菌体生长和乳酸合成的影响,筛选出了影响菌体生长和乳酸合成的3个主要因素,即混合氨基酸、KH2PO4和CaCO3;在此基础上利用最陡爬坡实验逼近最大响应区域；然后利用Box-Behnken实验设计及响应面分析法确定了最佳培养条件.经过3次实验验证,乳酸实际浓度与预测浓度十分接近,已经超过了在复合培养基中培养的水平.这些结果为L.paracasei的代谢流定量研究奠定了基础.