基于代谢计量分析的L-苏氨酸发酵过程优化

Study on the Fermentation Progress of L-Threonine by the Stoichiometric Analysis

目的:以L-苏氨酸生产菌株TRFC为供试菌株,基于代谢计量分析对发酵过程中底物葡萄糖、蔗糖的影响做理论分析并对发酵过程进行优化。方法:利用代谢计量学方法对L-苏氨酸生产菌株代谢途径进行分析,以碳源优化及5、10L发酵实验进行过程优化。结果与结论:发酵过程中,生物量及苏氨酸的产率取决于由葡萄糖转化的生物量占总量的摩尔比率,及转化的苏氨酸占总量的摩尔比率,最大理论值分别为24.1%、17.89%;种子及发酵培养基中葡萄糖与蔗糖的添加比例分别为2∶8、8∶2时得到最优值,L-苏氨酸最终产量为70g/L。

Objective： Glucose and surcose were used as substrates in the overproduction of L-threonine of Escherichia coli mutant, which was stoichimetrically analyzed and optimized. Methods： According to the stoichiometric analysis, the metabolic pathway of the E.coli mutant was made out, and overproduction of L-threonine was optimized by the 5 L, 10 L fermentation experiment and carbon source optimization. Results ＆ Conclusion： Factually, L-threonine productivity and biomass were performed by two factors in the feed media, percentage of glucose and percentage of sucrose, and theoretically the optimum of L-threonine productivity was 24.1%, it of biomass 17.89%. The maximum production of L-threonine was achieved 70 g/L, when m/m （glucose/sucrose） was 2：8 and 8：2 in the medium of seed and fermentation, respectively.