丙酮酸发酵过程中光滑球拟酵母过程功能的强化

Optimized Pyruvate Production Through Enhancing Torulopsis glabrata Process Performance

摘要:

对不同葡萄糖浓度下光滑球拟酵母分批发酵生产丙酮酸的动力学模型分析发现, 葡萄糖浓度是影响光滑球拟酵母发酵生产丙酮酸过程功能的关键因素。在发酵初始阶段, 低浓度葡萄糖可维持较高的菌体比生长速率; 对数生长中前期, 葡萄糖快速进料使菌体浓度接近最大值, 并实现碳流从菌体生长转向丙酮酸积累; 对数生长后期葡萄糖浓度控制在33.4 g/L以维持高丙酮酸对葡萄糖产率系数 (0.71 g/g)。采用奇异控制的葡萄糖流加方式, 在7 L发酵罐上控制不同发酵阶段葡萄糖浓度处于最佳水平以强化光滑球拟酵母过程功能, 丙酮酸产量 (83.1 g/L)、产率 (0.621 g/g)、生产强度[1.00 g/(L·h)]与分批发酵对比, 分别提高了21.3%、21.6%和29.9%。

Abstract:

Based on kinetic parameters analysis, a 4-stage glucose-control strategy was used to optimize pyruvate production by Torulopsis glabrata. At 0~18 h, 40 g/L glucose was fed to get a higher specific growth rate, and then glucose was quickly fed to the fermentation broth at 19~25 h to achieve the maximum dry cell concentration and to redirect the carbon flux from cell growth to pyruvate formation. At 26~63 h, a highest pyruvate yield (0.71 g/g) was achieved through maintaining glucose at 33.4 g/L by a singular control strategy. After 64 h, pyruvate fermentation was continued as batch process. A high concentration (83.1 g/L), yield (0.621 g/g) and productivity (1.00 g/(L·h)) of pyruvate were achieved by applying this strategy, which were 21.3%, 21.6% and 29.9% higher than that of the batch process.