The hydrogenase from the hyperthermophilic archaeon Pyrococcus furiosus: From basic research to possible future applications

Abstract

The tetrameric hydrogenase from the hyperthermophilic archaeon Pyrococcus furiosus has been genetically characterized and tested as catalyst in a light-mediated in vitro hydrogen production system under different experimental conditions. The genetic analysis of the hydrogenase points out a possible bifunctional nature of the enzyme in which the β and γ subunits might be responsible for elemental sulfur reduction, whereas the δ and α subunits could be associated to the hydrogenase activity. Experiments on photoinduced hydrogen production performed with the P. furiosus enzyme coupled to the semiconductor titanium dioxide in the presence of methylviologen as an electron carrier show that the system evolved H 2 with a rate as high as 0.5 μmoles/min/mg of TiO 2. Interestingly, H 2 is produced even in the absence of MV. Since the experimental data reported here indicate that the inactivation of the electron carrier is the limiting point of the system, the P. furiosus hydrogenase can be considered a promising catalyst for this kind of in vitro system.