First evidence for the presence of a hydrogenase in the sulfur-reducing bacterium Desulfuromonas acetoxidans

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