Hydrogenase I from the hyperthermophilic bacterium Aquifex aeolicus is a good candidate for biotechnol. devices thanks to its ability to oxidize hydrogen at high temp., even in the presence of oxygen and CO. In order to enhance the enzyme stability and the catalytic efficiency, we investigated the hydrogen oxidn. process with hydrogenase I embedded in a physiol.-like environment. Hydrogenase I partners in the metabolic chain, namely membrane quinone and cytochrome b, were purified and fully characterized. The complex hydrogenase I-cytochrome b was inserted into liposomes. Surface Plasmon Resonance revealed that quinone took part in the stabilization of the complex. By use of mol. modeling and electrochem. anal., enzyme stability has been demonstrated to be stronger and enzymic efficiency to be five times higher when hydrogenase is embedded into the liposomes. This result raises the possibility of using hydrogenases as biocatalysts in fuel cells. on SciFinder(R)