title: Genomic inference of the metabolism of cosmopolitan subsurface Archaea, Hadesarchaea.
abstract: The subsurface biosphere is largely unexplored and contains a broad diversity of uncultured microbes(1). Despite being one of the few prokaryotic lineages that is cosmopolitan in both the terrestrial and marine subsurface(2-4), the physiological and ecological roles of SAGMEG (South-African Gold Mine Miscellaneous Euryarchaeal Group) Archaea are unknown. Here, we report the metabolic capabilities of this enigmatic group as inferred from genomic reconstructions. Four high-quality (63-90% complete) genomes were obtained from White Oak River estuary and Yellowstone National Park hot spring sediment metagenomes. Phylogenomic analyses place SAGMEG Archaea as a deeply rooting sister clade of the Thermococci, leading us to propose the name Hadesarchaea for this new Archaeal class. With an estimated genome size of around 1.5 Mbp, the genomes of Hadesarchaea are distinctly streamlined, yet metabolically versatile. They share several physiological mechanisms with strict anaerobic Euryarchaeota. Several metabolic characteristics make them successful in the subsurface, including genes involved in CO and H2 oxidation (or H2 production), with potential coupling to nitrite reduction to ammonia (DNRA). This first glimpse into the metabolic capabilities of these cosmopolitan Archaea suggests they are mediating key geochemical processes and are specialized for survival in the subsurface biosphere.
authors: Department of Marine Science, University of Texas Austin, Marine Science Institute, Port Aransas, Texas 78373, USA.
authors: Brett J
authors: BJ
authors: Baker
authors: Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, SE-75123 Uppsala, Sweden.
authors: Jimmy H
authors: JH
authors: Saw
authors: Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, SE-75123 Uppsala, Sweden.
authors: Anders E
authors: AE
authors: Lind
authors: MARUM Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany.
authors: Cassandre Sara
authors: CS
authors: Lazar
authors: MARUM Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany.
authors: Kai-Uwe
authors: KU
authors: Hinrichs
authors: Department of Marine Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors: Andreas P
authors: AP
authors: Teske
authors: Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, SE-75123 Uppsala, Sweden.
authors: Thijs J G
authors: http://orcid.org/0000-0002-6898-6377
authors: TJ
authors: Ettema
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001105:Archaea / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D002248:Carbon Monoxide / Q000378:metabolism; D004783:Environmental Microbiology; D063366:Estuaries; D045482:Hot Springs; D006859:Hydrogen / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D009573:Nitrites; D000641:Ammonia; D002248:Carbon Monoxide; D006859:Hydrogen