Accumulation of pyruvate by changing the redox status in Escherichia coli.

Pyruvate was produced from glucose by Escherichia coli BW25113 that contained formate dehydrogenase (FDH) from Mycobacterium vaccae. In aerobic shake-flask culture (K (L) a = 4.9 min(-1)), the recombinant strain produced 6.7 g pyruvate l(-1) after 24 h with 4 g sodium formate l(-1) and a yield of 0.34 g pyruvate g glucose(-1). These values were higher than those of the original strain (0.2 g l(-1) pyruvate and 0.02 g pyruvate g glucose(-1)). Based on the reaction mechanism of FDH, the introduction of FDH into E. coli enhances the accumulation of pyruvate by the regeneration of NADH from NAD(+) since NAD(+) is a shared cosubstrate with the pyruvate dehydrogenase complex, which decarboxylates pyruvate to acetyl-CoA and CO(2). The oxygenation level was enough high to inactivate lactate dehydrogenase, which was of benefit to pyruvate accumulation without lactate as a by-product.