There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
Redox cofactors play crucial roles in the metabolic and regulatory network of living
organisms. We reported here the effect of introducing a heterogeneous NADH regeneration
system into Klebsiella oxytoca on cell growth and glycerol metabolism. Expression
of fdh gene from Candida boidinii in K. oxytoca resulted in higher intracellular concentrations
of both NADH and NAD(+) during the fermentation metaphase, with the ratio of NADH
to NAD(+) unaltered and cell growth unaffected, interestingly different from that
in engineered Escherichia coli, Lactococcus lactis, and others. Metabolic flux analysis
revealed that fluxes to 1,3-propanediol, ethanol, and lactate were all increased,
suggesting both the oxidative and reductive metabolisms of glycerol were enhanced.
It demonstrates that in certain microbial system NADH availability can be increased
with NADH to NAD(+) ratio unaltered, providing a new strategy to improve the metabolic
flux in those microorganisms where glycolysis is not the only central metabolic pathways.