Evidence for a tungsten-stimulated aldehyde dehydrogenase activity of Desulfovibrio simplex that oxidizes aliphatic and aromatic aldehydes with flavins as coenzymes

摘要

The aldehyde dehydrogenase activity of the sulfate-reducing bacterium Desulfovibrio simplex strain DSM 4141 was characterized in cell-free extracts. Oxygen-sensitive, constitutive aldehyde dehydrogenase activity was found in cells grown on L(+)-lactate, hydrogen, or vanillin with sulfate as the electron acceptor. A 1.83- to 2.6-fold higher specific activity was obtained in cells grown in media supplemented with 1 mu M WO42-. The aldehyde dehydrogenase in cell-free extracts catalyzed the oxidation of aliphatic (K-m < 20 mu M) and aromatic aldehydes (K-m < 0.32 mM) using methyl viologen as the electron acceptor. Flavins (FMN and FAD) were also active and are proposed to be the natural cofactors, while no activity was obtained with NAD(+) or NADP(+). (WO42-)-W-185 was incorporated in vivo into D. simplex; it was found exclusively in the soluble fraction (greater than or equal to 98%). Anionic-exchange chromatography demonstrated coelution of W-185 with two distinct peaks, the first one containing hydrogenase and formate dehydrogenase activities, and the second-one aldehyde dehydrogenase activity.