“…The second hypothesis tested was, therefore, that SFA act anti-methanogenic in methanogenic Archaea independent of the metabolic pathway used to form CH 4 . For that purpose, Methanosarcina mazei, able to grow without H 2 and CO 2 as substrates (Hovey et al, 2005), was cultivated on methanol to test whether this methanogenic pathway is also inhibited. A key coenzyme for any kind of methanogenesis and thus common to all methanogenic Archaea is the methyl-coenzyme M reductase (MCR) (Thauer, 1998).…”