Protonmotive force-driven synthesis of ATP during methane formation from molecular hydrogen and formaldehyde or carbon dioxide in Methanosarcina barkeri

Abstract

Methane formation from formaldehyde and H₂ or from carbon dioxide and H₂, as performed by cell suspensions of Methanosarcina barkeri, was coupled to ATP synthesis. In correspondence with this, methane formation was inhibited by N, N′-dicyclohexylcarbodiimide (DCCD), which at the same time, caused a decrease of the intracellular ATP concentration but only a slow decrease of the membrane potential. Addition of the uncoupler tetrachlorosalicylanilide (TCS) led to a relief of the inhibition of methane formation from CH₂O + H₂, but not from CO₂+ H₂.