Photosensitized production of hydrogen by hydrogenase in reversed micelles

Hydrogenase (hydrogen:ferricytochrome c(3) oxidoreductase, EC 1.12.2.1) from Desulfovibrio vulgaris was encapsulated in reversed micelles with cetyltrimethylammonium bromide as surfactant and a chloroform/octane mixture as solvent. Reducing equivalents for hydrogenase-catalyzed hydrogen production were provided by vectorial photosensitized electron transfer from a donor (thiophenol) in the organic phase through a surfactant-Ru(2+) sensitizer located in the interphase to methyl viologen concentrated in the aqueous core of the reversed micelle. The results show that reversed micelles provide a microenvironment that (i) stabilizes hydrogenase against inactivation and (ii) allows an efficient vectorial photosensitized electron and proton flow from the organic phase to hydrogenase in the aqueous phase.