title: Subglacial Lake Whillans microbial biogeochemistry: a synthesis of current knowledge.
abstract: Liquid water occurs below glaciers and ice sheets globally, enabling the existence of an array of aquatic microbial ecosystems. In Antarctica, large subglacial lakes are present beneath hundreds to thousands of metres of ice, and scientific interest in exploring these environments has escalated over the past decade. After years of planning, the first team of scientists and engineers cleanly accessed and retrieved pristine samples from a West Antarctic subglacial lake ecosystem in January 2013. This paper reviews the findings to date on Subglacial Lake Whillans and presents new supporting data on the carbon and energy metabolism of resident microbes. The analysis of water and sediments from the lake revealed a diverse microbial community composed of bacteria and archaea that are close relatives of species known to use reduced N, S or Fe and CH4 as energy sources. The water chemistry of Subglacial Lake Whillans was dominated by weathering products from silicate minerals with a minor influence from seawater. Contributions to water chemistry from microbial sulfide oxidation and carbonation reactions were supported by genomic data. Collectively, these results provide unequivocal evidence that subglacial environments in this region of West Antarctica host active microbial ecosystems that participate in subglacial biogeochemical cycling.
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA Department of Biology, Middlebury College, Middlebury, VT 05753, USA jmikucki@middlebury.edu.
authors.forename: J A
authors.initials: JA
authors.lastname: Mikucki
authors.affiliation: Hollings Marine Lab, College of Charleston, Charleston, SC 29412, USA.
authors.forename: P A
authors.identifier: http://orcid.org/0000-0001-5523-1429
authors.initials: PA
authors.lastname: Lee
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA.
authors.forename: D
authors.initials: D
authors.lastname: Ghosh
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Purcell
authors.affiliation: Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK.
authors.forename: A C
authors.initials: AC
authors.lastname: Mitchell
authors.affiliation: Department of Geosciences, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Mankoff
authors.affiliation: Earth and Planetary Sciences, University of California, Santa Cruz, CA, USA.
authors.forename: A T
authors.initials: AT
authors.lastname: Fisher
authors.affiliation: Earth and Planetary Sciences, University of California, Santa Cruz, CA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Tulaczyk
authors.affiliation: Institute for Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA.
authors.forename: S
authors.initials: S
authors.lastname: Carter
authors.affiliation: Institute for Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Siegfried
authors.affiliation: Institute for Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA.
authors.forename: H A
authors.initials: HA
authors.lastname: Fricker
authors.affiliation: Department of Geology and Environmental Geosciences Northern, Illinois University, DeKalb, IL 60115, USA.
authors.forename: T
authors.initials: T
authors.lastname: Hodson
authors.affiliation: Department of Geology and Environmental Geosciences Northern, Illinois University, DeKalb, IL 60115, USA.
authors.forename: J
authors.initials: J
authors.lastname: Coenen
authors.affiliation: Department of Geology and Environmental Geosciences Northern, Illinois University, DeKalb, IL 60115, USA.
authors.forename: R
authors.initials: R
authors.lastname: Powell
authors.affiliation: Department of Geology and Environmental Geosciences Northern, Illinois University, DeKalb, IL 60115, USA.
authors.forename: R
authors.initials: R
authors.lastname: Scherer
authors.affiliation: Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA.
authors.forename: T
authors.initials: T
authors.lastname: Vick-Majors
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Achberger
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: B C
authors.initials: BC
authors.lastname: Christner
authors.affiliation: Bristol Glaciology Centre, Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK.
authors.forename: M
authors.identifier: http://orcid.org/0000-0003-2071-3094
authors.initials: M
authors.lastname: Tranter
mesh_terms: D000864:Antarctic Regions; D059001:Aquatic Organisms / Q000382:microbiology; D001105:Archaea / Q000145:classification*; D001419:Bacteria / Q000145:classification*; D017753:Ecosystem; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology*; D046448:Ice Cover / Q000737:chemistry / Q000382:microbiology; D060106:Lakes / Q000737:chemistry* / Q000382:microbiology*
keywords: Antarctica; WISSARD; Whillans Ice Stream; geomicrobiology; microbial diversity; subglacial lakes