基于途径分析的L-谷氨酸发酵条件优化

应用途径分析方法分析了黄色短杆菌GDK-9由葡萄糖发酵生产L-谷氨酸的途径,确定了L-谷氨酸合成的理想途径和最大理论产率。通过比较途径分析所获得的反应模型,确定了α-酮戊二酸和柠檬酸是L-谷氨酸合成途径的关键节点。在此基础上改变外界环境因子,强化L-谷氨酸生物合成途径中关键节点柠檬酸的代谢流,减少副产物乳酸的生成,以提高L-谷氨酸产率。实验中采用脉冲流加补料方式,控制溶氧在10%左右,生物素亚适量法生产L-谷氨酸产量达到136g/L。

Application of Pathway Analysis for Optimization of L-glutamic Acid Production

Pathway analysis of the L-glutamic acid production by Brevibacterium flavum GDK-9 was conducted in this paper. Theoretical L-glutamic acid yield and flux distributions of the optimal L-glutamic acid biosynthesis pathway were determined. According to the pathway analysis, the L-glutamic acid produc- tion is expected to be raised by strengthening the flux of the key node such as citrate through changing the environmental factors. Therefore the effects of the pulsed fed-batch cultivation and the dissolved oxygen on the L-glutamic acid production were further studied. The L-glutamic acid production was finally raised to 130 g/L by applying the pulsed fed-batch cultivation and controlling the dissolved oxygen level of 10 %.