title: Detection and localization of two hydrogenases in Methylococcus capsulatus (Bath) and their potential role in methane metabolism.
abstract: Methylococcus capsulatus (Bath) was shown to contain two distinct hydrogenases, a soluble hydrogenase and a membrane-bound hydrogenase. This is the first report of a membrane-bound hydrogenase in methanotrophs. Both enzymes were expressed apparently constitutively under normal growth conditions. The soluble hydrogenase was capable of reducing NAD(+) with molecular hydrogen. The activities of both soluble and particulate methane monooxygenases could be driven by molecular hydrogen. This confirmed that molecular hydrogen could be used as a source of reducing power for methane oxidation. Hydrogen-driven methane monooxygenase activities tolerated elevated temperatures and moderate oxygen concentrations. The significance of these findings for biotechnological applications of methanotrophs is discussed.
authors.affiliation: Department of Biotechnology, University of Szeged, Hungary.
authors.forename: Tímea
authors.initials: T
authors.lastname: Hanczár
authors.forename: Robert
authors.initials: R
authors.lastname: Csáki
authors.forename: Levente
authors.initials: L
authors.lastname: Bodrossy
authors.forename: J Colin
authors.initials: JC
authors.lastname: Murrell
authors.forename: Kornél L
authors.initials: KL
authors.lastname: Kovács
mesh_terms: D006859:Hydrogen / Q000378:metabolism; D006864:Hydrogenase / Q000302:isolation & purification*; D008697:Methane / Q000378:metabolism; D020619:Methylococcus capsulatus / Q000201:enzymology*; D010088:Oxidoreductases / Q000302:isolation & purification; D010105:Oxygenases / Q000378:metabolism
chemical_list: D006859:Hydrogen; D010088:Oxidoreductases; C043296:nickel-iron hydrogenase; C021376:hydrogen dehydrogenase; D006864:Hydrogenase; D010105:Oxygenases; C021555:methane monooxygenase; D008697:Methane