First Evidence for the Presence of a Hydrogenase in the Sulfur-Reducing Bacterium Desulfuromonas acetoxidans

Hydrogenases, which are ubiquitous in sulfate-reducing bacteria, were previously thought to be absent from Desulfuromonas acetoxidans. For the first time, a hydrogenase from the strict anaerobic sulfur-respiring bacterium D. acetoxidans, grown on ethanol-malate, was detected and enriched. To assay the role of the hydrogenase in the energetic metabolism of D. acetoxidans, we examined the reactivity of the enzyme with polyheme cytochromes from the same bacterium.