Deconstructing <i>Methanosarcina acetivorans</i> into an acetogenic archaeon
Christian Schöne, Anja Poehlein, Nico Jehmlich, Norman Adlung, Rolf Daniel, Martin von Bergen�, Silvan Scheller, Michael Rother
Abstract
can dispense with methanogenesis for energy conservation completely. By targeted disruption of the methanogenic pathway, followed by adaptive evolution, a strain was created that sustained growth via carbon monoxide-dependent acetogenesis. A minute flux (less than 0.2% of the carbon monoxide consumed) through the methane-liberating reaction remained essential, indicating that currently living methanogens utilize metabolites of this reaction also for anabolic purposes. These results suggest that the metabolic flexibility of methanogenic archaea might be much greater than currently known. Also, our ability to deconstruct a methanogen into an acetogen by merely removing cellular functions provides experimental support for the notion that methanogenesis could have evolved from the reductive acetyl-coenzyme A pathway.