Redirecting reductant flux into hydrogen production via metabolic engineering of fermentative carbon metabolism in a cyanobacterium.

ABSTRACT: Some aquatic microbial oxygenic photoautotrophs (AMOPs) make hydrogen (H(2)), a carbon-neutral, renewable product derived from water, in low yields during autofermentation (anaerobic metabolism) of intracellular carbohydrates previously stored during aerobic photosynthesis. We have constructed a mutant (the ldhA mutant) of the cyanobacterium Synechococcus sp. strain PCC 7002 lacking the enzyme for the NADH-dependent reduction of pyruvate to D-lactate, the major fermentative reductant sink in this AMOP. Both nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS) metabolomic methods have shown that autofermentation by the ldhA mutant resulted in no D-lactate production and higher concentrations of excreted acetate, alanine, succinate, and hydrogen (

SUBMITTER: McNeely K 

PROVIDER: S-EPMC2916493 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature