在维生素限量添加的条件下,研究了添加氨基酸对丙酮酸发酵的影响.在发酵初始添加0.8g/L谷氨酸、0.6g/L酪氨酸和0.2g/L甲硫氨酸使丙酮酸产量分别提高77.5%,16.4%和11.8%.动力学分析表明,添加以上3种原料提高丙酮酸生产性能的原因在于用于细胞生长的葡萄糖下降,显著提高了细胞对葡萄糖的产率系数(Yx/s)和丙酮酸对葡萄糖的产率系数(Yp/s).添加氨基酸导致胞内NADH/NAD^+比下降,增加了胞内NAD^+可用度,加强了糖酵解速度,从而提高了丙酮酸生产强度.
The effect of amino acid on production of pyruvate by T. glabrata CCTCC M202019 was investigated. The pyruvate production was increased 23.5%, 16.4% and 11.8%, respectively, with 0.8 g/L glutamic acid, 0.6 g/L tyrosine and 0.2 g/L methionine fed to the fermentation medium at the initial fermentation. The principle of amino acids to enhance pyruvate production is that the amount of glucose used for cell growth was reduced, but the yields of cell and pyruvate on glucose (Yx/s and Yp/s) were increased. On the other hand, the concentration of intracellular NADH was decreased by amino acid addition, which resulted in higher glycolic flux and pyruvate production.