title: A microbial ecosystem beneath the West Antarctic ice sheet.
abstract: Liquid water has been known to occur beneath the Antarctic ice sheet for more than 40 years, but only recently have these subglacial aqueous environments been recognized as microbial ecosystems that may influence biogeochemical transformations on a global scale. Here we present the first geomicrobiological description of water and surficial sediments obtained from direct sampling of a subglacial Antarctic lake. Subglacial Lake Whillans (SLW) lies beneath approximately 800 m of ice on the lower portion of the Whillans Ice Stream (WIS) in West Antarctica and is part of an extensive and evolving subglacial drainage network. The water column of SLW contained metabolically active microorganisms and was derived primarily from glacial ice melt with solute sources from lithogenic weathering and a minor seawater component. Heterotrophic and autotrophic production data together with small subunit ribosomal RNA gene sequencing and biogeochemical data indicate that SLW is a chemosynthetically driven ecosystem inhabited by a diverse assemblage of bacteria and archaea. Our results confirm that aquatic environments beneath the Antarctic ice sheet support viable microbial ecosystems, corroborating previous reports suggesting that they contain globally relevant pools of carbon and microbes that can mobilize elements from the lithosphere and influence Southern Ocean geochemical and biological systems.
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
authors.forename: Brent C
authors.initials: BC
authors.lastname: Christner
authors.affiliation: Department of Land Resources and Environmental Science, Montana State University, Bozeman, Montana 59717, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Priscu
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Achberger
authors.affiliation: Institute for the Dynamics of Environmental Processes - CNR, Venice, and Department of Environmental Sciences, Informatics and Statistics, Ca'Foscari University of Venice, Venice 30123, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Barbante
authors.affiliation: Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, USA.
authors.forename: Sasha P
authors.initials: SP
authors.lastname: Carter
authors.affiliation: 1] Physics Department, St Olaf College, Northfield, Minnesota 55057, USA [2] Courant Institute of Mathematical Sciences, New York University, New York, New York 10012, USA (K.C.).
authors.forename: Knut
authors.initials: K
authors.lastname: Christianson
authors.affiliation: Department of Land Resources and Environmental Science, Montana State University, Bozeman, Montana 59717, USA.
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Michaud
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: Jill A
authors.initials: JA
authors.lastname: Mikucki
authors.affiliation: Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth SY23 3DB, UK.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Mitchell
authors.affiliation: Department of Earth Science, Montana State University, Bozeman, Montana 59717, USA.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Skidmore
authors.affiliation: Department of Land Resources and Environmental Science, Montana State University, Bozeman, Montana 59717, USA.
authors.forename: Trista J
authors.initials: TJ
authors.lastname: Vick-Majors
mesh_terms: D000864:Antarctic Regions; D059001:Aquatic Organisms / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001105:Archaea / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D017753:Ecosystem; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D046448:Ice Cover / Q000737:chemistry; D060106:Lakes / Q000737:chemistry / Q000382:microbiology*; D009792:Oceans and Seas; D010802:Phylogeny
chemical_list: D002244:Carbon