Exceptionally High Rates of Biological Hydrogen Production by Biomimetic In Vitro Synthetic Enzymatic Pathways.
Hydrogen production by water splitting energized by biomass sugars is one of the most promising technologies for distributed green H2production. Direct H2generation from NADPH, catalysed by an NADPH-dependent, soluble [NiFe]-hydrogenase (SH1) is thermodynamically unfavourable, resulting in slow volumetric productivity. We designed the biomimetic electron transport chain from NADPH to H2by the introduction of an oxygen-insensitive electron mediator benzyl viologen (BV) and an enzyme (NADPH rubredoxin oxidoreductase, NROR), catalysing electron transport between NADPH and BV. The H2generation rates using this biomimetic chain increased by approximately five-fold compared to those catalysed only by SH1. The peak volumetric H2productivity via the in vitro enzymatic pathway comprised of hyperthermophilic glucose 6-phosphate dehydrogenase, 6-phosphogluconolactonase, and 6-phosphogluconate dehydrogenase, NROR, and SH1 was 310 mmol H2/L h-1, the highest rate yet reported. The concept of biomimetic electron transport chains could be applied to both in vitro and in vivo H2production biosystems and artificial photosynthesis.
Biological Systems Engineering Department, Virginia Tech, 304 Seitz Hall, Blacksburg, Virginia, 24061, USA.
Eui-Jin
EJ
Kim
Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA.
Chang-Hao
CH
Wu
Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA.
Michael W W
MW
Adams
Biological Systems Engineering Department, Virginia Tech, 304 Seitz Hall, Blacksburg, Virginia, 24061, USA. ypzhang@vt.edu.|Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China. ypzhang@vt.edu.
Y-H Percival
YP
Zhang
electron mediator; electron-transport chain; hydrogen production; synthetic enzymatic pathway; water splitting