Electron transport in Peptostreptococcus elsdenii

Abstract

The electron-transfer reactions associated with acyl-CoA dehydrogenase (acyl-CoA: DPN⁺ oxidoreductase), hydrogenase (EC 1.98.1.1) and lactic dehydrogenase (dl-lactate: (acceptor) oxidoreductase) in the rumen microorganism Peptostreptococcus elsdenii were studied and a pathway of electron transport in the organism proposed. Acyl-CoA dehydrogenase was resolved into dehydrogenase and an associated electron-transport protein (Fraction II) which accepts electrons from DPNH and passes them to the dehydrogenase. The two components were purified and partially characterized. Data indicating the presence of a ferredoxin-linked DPN⁺ reductase (reduced ferredoxin: DPN⁺ oxidoreductase) are presented.