L-缬氨酸发酵过程的代谢流分析

通过对L-缬氨酸发酵过程的代谢流进行分析，可获得提高L-缬氨酸产量的代谢调控手段。本论文应用流量平衡模型，通过物料衡算和MATLAB线性规划方法得到了L-缬氨酸发酵过程的代谢流量分布，并研究了L-缬氨酸发酵过程中的NADPH及ATP的代谢通量分布。代谢流分析结果表明，在分批培养生成L-缬氨酸的过程中，HMP是L-缬氨酸生物合成的关键途径，发酵过程中的ATP大部分以无效循环的形式消耗掉，应从遗传改造和发酵控制方面增大EMP途径的流量，降低TCA循环的代谢流，减少副产氨基酸的生成，进一步提高缬氨酸的产率。

Analysis of L-waline biosynthesis mechanism by metabolic flux balance model

Metabolic flux analysis(MFA)plays an important role in guiding the genetic manipulation in metabolic engi-neering.It can be used to provide theory guide for the fermentation control by analyzing metabolic principle node and meta-bolic flux.Using metabolic flux balance model,distribution of L-valine synthesis was established by material balances andlinear programming method,and the metabolic flux distribution of NADPH and ATP were studied.As the results shown,HMP is the key pathway of L-valine biosynthesis in batch fermentation.Most part of ATP in fermentation was consumed infutile cycle.The production of L-valine should be improved from the genetic manipulation and fermentation control throughreducing byproduct of amino acid and decreasing the metabolic flux of TCA cycle.