碳源对琥珀酸放线杆菌发酵产丁二酸的影响及其代谢流量分析

Effect of Different Carbon Sources on Succinic Acid Production of Actinobacillus succinogenes and Metabolic Flux Analysis

在厌氧条件下,Actinobacillus succinogenes能够利用单糖、双糖和糖醇等碳水化合物发酵生成丁二酸,其中以山梨醇为碳源时丁二酸的产量最高。代谢流量分析结果表明:与葡萄糖发酵相比较,由于代谢系统中积累了更多的NADH,使得代谢网络关键节点PYR和AcCoA处的代谢流量分配有了较大的变化,导致更多的碳源流向丁二酸和乙醇,而乙酸和甲酸的分泌相对减少。

In anaerobic bottles fermentation, glucose, fructose, xylose, lactose, maltose, sucrose and sugar alcohols could be used to produce succinic acid with Actinobacillus succinogenes. When sorbitol was utilized as the carbon source in the batch fermentation, more succinate and ethanol were produced compared with those using glucose, while producing less acetate and formate. The metabolic flux analysis results showed that the flux partitioning at PEP node was stable when glucose was replaced by sorbitol, but the flux partitioning at PYR and AcCoA nodes changed a lot because more reducing power （NADH） was generated to meet the more requirement the synthesis of succinate and ethanol.