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Project Progress

Hydrogenotrophic methanogenesis occurs in a variety of anaerobic habitats, may have played an important role on early earth, and could be a dominant metabolism on other planetary bodies. In previous years we published our genome sequence of Methanoccoccus maripaludis, a model species of hydrogenotrophic methanogen and a member of the domain Archaea. In the past year we have made considerable progress in the post-genomics of M. maripaludis. Thus, we used chemostat-grown cultures and expression arrays to learn how M. maripaludis responds to conditions in which growth is limited by the supply of hydrogen, an important electron donor in methanogenesis. A manuscript describing this work is currently in preparation. In a related project, we published two papers in the past year on the transcriptomics and proteomics of a mutant deficient in a specific hydrogenase. Our studies have also given us insight into nitrogen regulation in the Archaea. Not surprisingly, the components of the regulatory apparatus are different in this branch of life, and we have published two papers describing this apparatus in detail. Finally, we continue to collaborate with David Stahl on the study of a metabolic co-culture between a sulfate reducer and M. maripaludis.