Abstract：
Pyruvate (Pyr) is the end product of the glycolysis pathway. Pyr is also renewable and is further metabolized to produce formate, which is the precursor of H2, via pyruvate formate lyase (PFL) under anaerobic conditions. The formate is excluded and re-imported via the formate channel and is then converted to H2 via the formate hydrogenlyase (FHL) complex. In H2 producing marine vibrios, such as Vibrio tritonius and Vibrio porteresiae in the Porteresiae clade of the family Vibrionaceae, apparent but inefficient H2 production from Pyr has been observed. To elucidate the molecular mechanism of why this inefficient H2 production is observed in Pry-metabolized marine vibrio cells and how glycolysis affects those H2 productions of marine vibrios, the \"Core Transcriptome\" approach to find common gene expressions of those two major H2 producing Vibrio species in Pyr metabolism was first applied. In the Pyr-metabolized vibrio cells, genes for the \"Phosphoenolpyruvate (PEP)-Pyruvate-Oxalate (PPO)\" node, due to energy saving, and PhoB-, RhaR-, and DeoR-regulons were regulated. Interestingly, a gene responsible for oxalate/formate family antiporter was up-regulated in Pyr-metabolized cells compared to those of Glc-metabolized cells, which provides new insights into the uses of alternative formate exclusion mechanics due to energy deficiencies in Pyr-metabolized marine vibrios cells. We further discuss the contribution of the Embden-Meyerhof-Parnas (EMP) pathway to efficient H2 production in marine vibrios.
摘要：
丙酮酸(Pyr)是糖酵解途径的最终产物。Pyr也是可再生的，并进一步代谢产生甲酸盐，在厌氧条件下通过丙酮酸甲酸裂解酶（PFL）是H2的前体。排除甲酸盐并通过甲酸盐通道重新输入,然后通过甲酸盐水解酶(FHL)复合物转化为H2。在H2生产海洋弧菌中，例如弧菌科的梭菌进化枝中的Tritonius弧菌和porteresiae弧菌，已观察到Pyr产生明显但效率低下的H2。为了阐明为什么在Pry代谢的海洋弧菌细胞中观察到这种低效的H2产生的分子机制，以及糖酵解如何影响海洋弧菌的H2产生，首先应用了“核心转录组”方法来寻找Pyr代谢中这两种主要的产生H2的弧菌的共同基因表达。在Pyr代谢的弧菌细胞中，“磷酸烯醇丙酮酸（PEP）-丙酮酸-草酸盐（PPO）”节点的基因，由于节能，还有PhoB-,RhaR-,和DeoR-调节子被调节。有趣的是,与Glc代谢细胞相比，Pyr代谢细胞中负责草酸盐/甲酸家族反转运蛋白的基因上调，由于Pyr代谢的海洋弧菌细胞的能量不足，这为替代甲酸盐排斥力学的使用提供了新的见解。我们进一步讨论了Embden-Meyerhof-Parnas（EMP）途径对海洋弧菌中高效H2生产的贡献。
