Project description:Maider J. Echeveste Medrano and colleagues characterized the physiological and metabolic response of freshwater methanotrophic archaea to salt stress. The study performed metaproteomics, gene expression profiles and dedicated metabolomics to identify the pathways involved in the salt stress response and the osmolyte present in anaerobic methanotrophic archaea. Correspondence to Cornelia U. Welte c.welte@science.ru.nl
Project description:Our goal is to convert methane efficiently into liquid fuels that may be more readily transported. Since aerobic oxidation of methane is less efficient, we focused on anaerobic processes to capture methane, which are accomplished by anaerobic methanotrophic archaea (ANME) in consortia. However, no pure culture capable of oxidizing and growing on methane anaerobically has been isolated. In this study, Methanosarcina acetivorans, an archaeal methanogen, was metabolically engineered to take up methane, rather than to generate it. To capture methane, we cloned the DNA coding for the enzyme methyl-coenzyme M reductase (Mcr) from an unculturable archaeal organism from a Black Sea mat into M. acetivorans to effectively run methanogenesis in reverse. The engineered strain produces primarily acetate, and our results demonstrate that pure cultures can grow anaerobically on methane.