氧化还原电位对Actinobacillus succinogenes厌氧发酵生产丁二酸的影响

为提高琥珀酸放线菌Actinobacillus succinogenes CGMCC1593厌氧发酵产丁二酸的水平。研究了以葡萄糖为C源，发酵液中不同氧化还原电位（VORP）对A．succirtogenes CGMCC1593生长和代谢产物分布的影响。结果表明：菌体生长和丁二酸积累的较佳VORP分别为-220mV和-270mV；利用代谢流分析法，比较VORP在-220mV和-270mV时发酵对数生长期（8h）和稳定期（20h）的代谢通量分布，以及发酵过程中磷酸烯醇式丙酮酸（PEP）、丙酮酸（Pyr）节点，NADH通量分配的变化，由此得出在VORP为-270mV时，NADH总通量和丁二酸方向代谢通量增幅明显。在发酵过程中，通过降低VORP至-270mV，使丁二酸的产率从70％提高到85％。

Effects of culture redox potential on succinic acid production by Actinobacillus succinogenes in anaerobic fermentation

To improve the succinic acid productivity by Actinobacillus succinogenes CGMCC1593 in anaerobic fermentation, the effects of ox-reduction potential （ VORP） cultue on cell growth, biosynthesis and glucose-based carbon flux were compared. The result indicated that the cell growth was fast at -220 mV and the suecinic acid yield was high at -270 mV. Metabolic carbon flux analysis was used to evaluate the effects of -220 mV and -270 mV based on the yaried distributions of carbon flux fraction at the phosphoenol pyruvate （PEP） node, pyruvate （Pyr） nodes, and flux distribution of NADH, during the logarithmic cell growth（8 h） and metabolic stabilization（20 h） stages of the batch fermentation ofA. succinogenes CGMCC1593. It was shown that fraction of carbon flux at NADH and suecinic acid increased at a VORP of -270 mV. By decreasing VORP to -270 mV at the end of period of logarithmic ceil growth, suceinic acid yield was increased from 70% to 85%.