The activity of two forms of nitrogenase from Rhodopseudomonas capsulata in the presence of different electron donors

Abstract The active form of Rhodopseudomonas capsulata nitrogenase is active in vitro when dithionite or ferredoxins from this bacterium are used as electron donors. The presence of the activating nitrogenase enzyme and Mn²⁺ ions is needed for functioning of the inactive form of Rh. capsulata nitrogenase in vitro with the use of dithionite as an electron donor. The use of Rh. capsulata ferredoxins as electron donors in vitro makes the inactive form of nitrogenase fully active as is the case in vivo.