title: Bacteria beneath the West Antarctic ice sheet.
abstract: Subglacial environments, particularly those that lie beneath polar ice sheets, are beginning to be recognized as an important part of Earth's biosphere. However, except for indirect indications of microbial assemblages in subglacial Lake Vostok, Antarctica, no sub-ice sheet environments have been shown to support microbial ecosystems. Here we report 16S rRNA gene and isolate diversity in sediments collected from beneath the Kamb Ice Stream, West Antarctic Ice Sheet and stored for 15 months at 4 degrees C. This is the first report of microbes in samples from the sediment environment beneath the Antarctic Ice Sheet. The cells were abundant ( approximately 10(7) cells g(-1)) but displayed low diversity (only five phylotypes), likely as a result of enrichment during storage. Isolates were cold tolerant and the 16S rRNA gene diversity was a simplified version of that found in subglacial alpine and Arctic sediments and water. Although in situ cell abundance and the extent of wet sediments beneath the Antarctic ice sheet can only be roughly extrapolated on the basis of this sample, it is clear that the subglacial ecosystem contains a significant and previously unrecognized pool of microbial cells and associated organic carbon that could potentially have significant implications for global geochemical processes.
authors.affiliation: Department of Environmental Sciences, University of California, Riverside, CA 92506, USA. brian.lanoil@ualberta.ca
authors.forename: Brian
authors.initials: B
authors.lastname: Lanoil
authors.forename: Mark
authors.initials: M
authors.lastname: Skidmore
authors.forename: John C
authors.initials: JC
authors.lastname: Priscu
authors.forename: Sukkyun
authors.initials: S
authors.lastname: Han
authors.forename: Wilson
authors.initials: W
authors.lastname: Foo
authors.forename: Stefan W
authors.initials: SW
authors.lastname: Vogel
authors.forename: Slawek
authors.initials: S
authors.lastname: Tulaczyk
authors.forename: Hermann
authors.initials: H
authors.lastname: Engelhardt
mesh_terms: D000864:Antarctic Regions; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification*; D044822:Biodiversity; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D020459:Genes, rRNA; D019015:Geologic Sediments / Q000382:microbiology*; D046448:Ice Cover; D008969:Molecular Sequence Data; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S