Photosynthetic electron partitioning between [FeFe]-hydrogenase and ferredoxin:NADP+-oxidoreductase (FNR) enzymes in vitro
Author(s)Yacoby, Iftach; Pochekailov, Sergii; Zhang, Shuguang; Toporik, Hila; Ghirardi, Maria L.; King, Paul W.; ... Show more Show less
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Photosynthetic water splitting, coupled to hydrogenase-catalyzed hydrogen production, is considered a promising clean, renewable source of energy. It is widely accepted that the oxygen sensitivity of hydrogen production, combined with competition between hydrogenases and NADPH-dependent carbon dioxide fixation are the main limitations for its commercialization. Here we provide evidence that, under the anaerobic conditions that support hydrogen production, there is a significant loss of photosynthetic electrons toward NADPH production in vitro. To elucidate the basis for competition, we bioengineered a ferredoxin-hydrogenase fusion and characterized hydrogen production kinetics in the presence of Fd, ferredoxin:NADP+-oxidoreductase (FNR), and NADP+. Replacing the hydrogenase with a ferredoxin-hydrogenase fusion switched the bias of electron transfer from FNR to hydrogenase and resulted in an increased rate of hydrogen photoproduction. These results suggest a new direction for improvement of biohydrogen production and a means to further resolve the mechanisms that control partitioning of photosynthetic electron transport.
DepartmentMassachusetts Institute of Technology. Center for Biomedical Engineering; Massachusetts Institute of Technology. Department of Chemical Engineering
Proceedings of the National Academy of Sciences
Proceedings of the National Academy of Sciences (PNAS)
Yacoby, I. et al. “Photosynthetic electron partitioning between [FeFe]-hydrogenase and ferredoxin:NADP+-oxidoreductase (FNR) enzymes in vitro.” Proceedings of the National Academy of Sciences 108.23 (2011): 9396-9401. Web. 2 Feb. 2012.
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