ISBN: 978-83-60043-10-3 - eurobic9

Eurobic9, 2-6 September, 2008, Wrocław, Poland
P64. Hydrogen Production by Hydrogenases in the Presence of Oxygen
G. Goldet, F. Armstrong
Inorganic Chemistry Laboratory, Univerity of Oxford, South Parks Road, OX1 3JP, Oxford, United Kingdom
e-mail: gabrielle.goldet@chem.ox.ac.uk
Investigating biological, photosynthetic H2 production is a complex process and the subject of intense, exciting
research.[1] The question is: could biological systems be harnessed in a future technology for solar energy
capture and fuel production? The hydrogenases are a family of metalloenzymes which reversibly catalyse H2
from water and electricity.[2] As one of the terminal electron acceptors in the photosynthetic apparatus, they
produce H2 by reducing protons with electrons harvested from light-activated water splitting. Elechtrochemistry
has been used to probe and refine our understanding of H2 production by hydrogenases and to investigate the
capacity for H2 production in the presence of O2, H2 and CO[3, 4] by quantifying any resulting inhibition, all
physiologically relevant inhibitors. Hydrogenases vary in their tolerance to O2 depending on the metals present
in their bimetallic active site; the so-called [NiFe]-hydrogenases are generally thought to be more tolerant to O2
whilst the [FeFe]-hydrogenases are permanently damaged by O2. A novel electrochemical experimental design
has been used to show that both types of hydrogenase are capable of H2 production in the presence of O2, [3, 4]
activity which was previously considered to be impossible in the case of the [FeFe]-hydrogenase. This is thus the
first proof that hydrogenases have this capacity. These findings open up a whole new area of electrochemical
study of H2 evolution and give hope for technological applications of hydrogenase molecules in their native
environments or inorganic hydrogenase mimics as biological H2 producers.
References:
[1] [1] M.L. Ghirardi, M.C. Posewitz, P.-C. Maness, A. Dubini, J. Yu, and M. Seibert, Annu. Rev. Plant Biol.,
2007, 58, 71
[2] K.A.V Vincent, A. Parkin, and F.A. Armstrong, Chem. Rev., 2007, 107, 4366
[3] G. Goldet, A.-M. Wait, J.A. Cracknell, K.A. Vincent, M. Ludwig, O. Lenz, B. Friedrich, and F.A.
Armstrong, J. Am. Chem. Soc., Accepted, 15/05/08
[4] A. Parkin, G.Goldet, C. Cavazza, J. Fontecilla-Camps and F. A. Armstrong, J. Am. Chem. Soc. Submitted
16/05/08
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