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Schuler CG, Winebrenner DP, Elam WT, Burnett J, Boles BW, Mikucki JA. Microbial Transport by a Descending Ice Melting Probe: Implications for Subglacial and Ocean World Exploration. ASTROBIOLOGY 2023; 23:1153-1164. [PMID: 37279037 DOI: 10.1089/ast.2021.0106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ocean Worlds beneath thick ice covers in our solar system, as well as subglacial lakes on Earth, may harbor biological systems. In both cases, thick ice covers (>100 s of meters) present significant barriers to access. Melt probes are emerging as tools for reaching and sampling these realms due to their small logistical footprint, ability to transport payloads, and ease of cleaning in the field. On Earth, glaciers are immured with various abundances of microorganisms and debris. The potential for bioloads to accumulate around and be dragged by a probe during descent has not previously been investigated. Due to the pristine nature of these environments, minimizing and understanding the risk of forward contamination and considering the potential of melt probes to act as instrument-induced special regions are essential. In this study, we examined the effect that two engineering descent strategies for melt probes have on the dragging of bioloads. We also tested the ability of a field cleaning protocol to rid a common contaminant, Bacillus. These tests were conducted in a synthetic ice block immured with bioloads using the Ice Diver melt probe. Our data suggest minimal dragging of bioloads by melt probes, but conclude that modifications for further minimization and use in special regions should be made.
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Affiliation(s)
- Caleb G Schuler
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Dale P Winebrenner
- Applied Physics Laboratory, University of Washington, Seattle, Washington, USA
| | - W Timothy Elam
- Applied Physics Laboratory, University of Washington, Seattle, Washington, USA
| | - Justin Burnett
- Applied Physics Laboratory, University of Washington, Seattle, Washington, USA
| | - Bruce W Boles
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Jill A Mikucki
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
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2
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Varliero G, Lebre PH, Frey B, Fountain AG, Anesio AM, Cowan DA. Glacial Water: A Dynamic Microbial Medium. Microorganisms 2023; 11:1153. [PMID: 37317127 DOI: 10.3390/microorganisms11051153] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/15/2023] [Accepted: 04/19/2023] [Indexed: 06/16/2023] Open
Abstract
Microbial communities and nutrient dynamics in glaciers and ice sheets continuously change as the hydrological conditions within and on the ice change. Glaciers and ice sheets can be considered bioreactors as microbiomes transform nutrients that enter these icy systems and alter the meltwater chemistry. Global warming is increasing meltwater discharge, affecting nutrient and cell export, and altering proglacial systems. In this review, we integrate the current understanding of glacial hydrology, microbial activity, and nutrient and carbon dynamics to highlight their interdependence and variability on daily and seasonal time scales, as well as their impact on proglacial environments.
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Affiliation(s)
- Gilda Varliero
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Pedro H Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
| | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Andrew G Fountain
- Departments of Geology and Geography, Portland State University, Portland, OR 97212, USA
| | - Alexandre M Anesio
- Department of Environmental Science, iClimate, Aarhus University, DK-4000 Roskilde, Denmark
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
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3
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Van Volkenburg T, Benzing JS, Craft KL, Ohiri K, Kilhefner A, Irons K, Bradburne C. Microfluidic Chromatography for Enhanced Amino Acid Detection at Ocean Worlds. ASTROBIOLOGY 2022; 22:1116-1128. [PMID: 35984944 PMCID: PMC9508454 DOI: 10.1089/ast.2021.0182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 04/18/2022] [Indexed: 06/15/2023]
Abstract
Increasing interest in the detection of biogenic signatures, such as amino acids, on icy moons and bodies within our solar system has led to the development of compact in situ instruments. Given the expected dilute biosignatures and high salinities of these extreme environments, purification of icy samples before analysis enables increased detection sensitivity. Herein, we outline a novel compact cation exchange method to desalinate proteinogenic amino acids in solution, independent of the type and concentration of salts in the sample. Using a modular microfluidic device, initial experiments explored operational limits of binding capacity with phenylalanine and three model cations, Na+, Mg2+, and Ca2+. Phenylalanine recovery (94-17%) with reduced conductivity (30-200 times) was seen at high salt-to-amino-acid ratios between 25:1 and 500:1. Later experiments tested competition between mixtures of 17 amino acids and other chemistries present in a terrestrial ocean sample. Recoveries ranged from 11% to 85% depending on side chain chemistry and cation competition, with concentration shown for select high affinity amino acids. This work outlines a nondestructive amino acid purification device capable of coupling to multiple downstream analytical techniques for improved characterization of icy samples at remote ocean worlds.
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Affiliation(s)
| | | | - Kathleen L. Craft
- Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
| | - Korine Ohiri
- Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
| | - Ashley Kilhefner
- Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
| | - Kristen Irons
- University of North Carolina at Chapel Hill College of Arts and Sciences, Chapel Hill, North Carolina, USA
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4
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Glaciers as microbial habitats: current knowledge and implication. J Microbiol 2022; 60:767-779. [DOI: 10.1007/s12275-022-2275-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/04/2022] [Accepted: 07/04/2022] [Indexed: 10/16/2022]
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5
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Survival strategies of an anoxic microbial ecosystem in Lake Untersee, a potential analog for Enceladus. Sci Rep 2022; 12:7376. [PMID: 35513542 PMCID: PMC9070616 DOI: 10.1038/s41598-022-10876-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 03/23/2022] [Indexed: 11/25/2022] Open
Abstract
Lake Untersee located in Eastern Antarctica, is a perennially ice-covered lake. At the bottom of its southern basin lies 20 m of anoxic, methane rich, stratified water, making it a good analog for Enceladus, a moon of Saturn. Here we present the first metagenomic study of this basin and detail the community composition and functional potential of the microbial communities at 92 m, 99 m depths and within the anoxic sediment. A diverse and well-populated microbial community was found, presenting the potential for Enceladus to have a diverse and abundant community. We also explored methanogenesis, sulfur metabolism, and nitrogen metabolism, given the potential presence of these compounds on Enceladus. We found an abundance of these pathways offering a variety of metabolic strategies. Additionally, the extreme conditions of the anoxic basin make it optimal for testing spaceflight technology and life detection methods for future Enceladus exploration.
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6
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Epova EY, Shevelev AB, Akbayev RM, Biryukova YK, Zylkova MV, Bogdanova ES, Guseva MA, Tynio YY, Egorov VV. Heterotrophic Microbiota from the Oligotrophic Waters of Lake Vostok, Antarctica. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19074025. [PMID: 35409708 PMCID: PMC8998000 DOI: 10.3390/ijerph19074025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/26/2022] [Accepted: 03/27/2022] [Indexed: 11/16/2022]
Abstract
Lake Vostok is the deepest lake of Antarctica but has poor accessibility for study due to a thick glacial cover, however, water samples of this lake have become available for study just recently. Previously, only the microbiome of the ice cover samples was characterized. Here we report results of bacteriological seeding with subsequent identification of the heterotrophic microorganisms (bacteria and micellar fungi) present by 16S rDNA sequencing as well as results of a direct molecular study of the water microbiome. Surprisingly, the data obtained gave evidence of a predominant occurrence of common chemoorganotrophs that were rather psychrotolerant than psychrophilic. We isolated and described strains belonging to eight heterotrophic microbial species able to grow in a rich medium: six bacterial strains belonging to the species Microbacterium testaceum and Microbacterium trichothecenolyticum, Brevundimonas diminuta, Sphingomonas oligophenolica, Sphingomonas sp. and Sphingobium limneticum; and two fungal strains belonging to Dendryphion sp. and Cladosporium fusiforme. Direct study of 16S rDNA purified water samples confirmed the predominance of the Brevundimonas, Microbacterium, Bradyrhizobium, and Bacillus (Bacillus cereus) genera.
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Affiliation(s)
- Ekaterina Y. Epova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia; (E.Y.E.); (A.B.S.); (M.V.Z.); (E.S.B.); (M.A.G.); (Y.Y.T.)
| | - Alexei B. Shevelev
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia; (E.Y.E.); (A.B.S.); (M.V.Z.); (E.S.B.); (M.A.G.); (Y.Y.T.)
| | - Ramazan M. Akbayev
- Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology, 109472 Moscow, Russia; (R.M.A.); (V.V.E.)
| | - Yulia K. Biryukova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia; (E.Y.E.); (A.B.S.); (M.V.Z.); (E.S.B.); (M.A.G.); (Y.Y.T.)
- Correspondence: ; Tel.: +7-909-682-85-61
| | - Marina V. Zylkova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia; (E.Y.E.); (A.B.S.); (M.V.Z.); (E.S.B.); (M.A.G.); (Y.Y.T.)
| | - Elena S. Bogdanova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia; (E.Y.E.); (A.B.S.); (M.V.Z.); (E.S.B.); (M.A.G.); (Y.Y.T.)
| | - Marina A. Guseva
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia; (E.Y.E.); (A.B.S.); (M.V.Z.); (E.S.B.); (M.A.G.); (Y.Y.T.)
| | - Yaroslav Y. Tynio
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia; (E.Y.E.); (A.B.S.); (M.V.Z.); (E.S.B.); (M.A.G.); (Y.Y.T.)
| | - Vladislav V. Egorov
- Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology, 109472 Moscow, Russia; (R.M.A.); (V.V.E.)
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7
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Extant Earthly Microbial Mats and Microbialites as Models for Exploration of Life in Extraterrestrial Mat Worlds. Life (Basel) 2021; 11:life11090883. [PMID: 34575032 PMCID: PMC8468739 DOI: 10.3390/life11090883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/13/2021] [Accepted: 08/25/2021] [Indexed: 02/05/2023] Open
Abstract
As we expand the search for life beyond Earth, a water-dominated planet, we turn our eyes to other aquatic worlds. Microbial life found in Earth's many extreme habitats are considered useful analogs to life forms we are likely to find in extraterrestrial bodies of water. Modern-day benthic microbial mats inhabiting the low-oxygen, high-sulfur submerged sinkholes of temperate Lake Huron (Michigan, USA) and microbialites inhabiting the shallow, high-carbonate waters of subtropical Laguna Bacalar (Yucatan Peninsula, Mexico) serve as potential working models for exploration of extraterrestrial life. In Lake Huron, delicate mats comprising motile filaments of purple-pigmented cyanobacteria capable of oxygenic and anoxygenic photosynthesis and pigment-free chemosynthetic sulfur-oxidizing bacteria lie atop soft, organic-rich sediments. In Laguna Bacalar, lithification by cyanobacteria forms massive carbonate reef structures along the shoreline. Herein, we document studies of these two distinct earthly microbial mat ecosystems and ponder how similar or modified methods of study (e.g., robotics) would be applicable to prospective mat worlds in other planets and their moons (e.g., subsurface Mars and under-ice oceans of Europa). Further studies of modern-day microbial mat and microbialite ecosystems can add to the knowledge of Earth's biodiversity and guide the search for life in extraterrestrial hydrospheres.
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8
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Gutt J, Isla E, Xavier JC, Adams BJ, Ahn IY, Cheng CHC, Colesie C, Cummings VJ, di Prisco G, Griffiths H, Hawes I, Hogg I, McIntyre T, Meiners KM, Pearce DA, Peck L, Piepenburg D, Reisinger RR, Saba GK, Schloss IR, Signori CN, Smith CR, Vacchi M, Verde C, Wall DH. Antarctic ecosystems in transition - life between stresses and opportunities. Biol Rev Camb Philos Soc 2020; 96:798-821. [PMID: 33354897 DOI: 10.1111/brv.12679] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 12/23/2022]
Abstract
Important findings from the second decade of the 21st century on the impact of environmental change on biological processes in the Antarctic were synthesised by 26 international experts. Ten key messages emerged that have stakeholder-relevance and/or a high impact for the scientific community. They address (i) altered biogeochemical cycles, (ii) ocean acidification, (iii) climate change hotspots, (iv) unexpected dynamism in seabed-dwelling populations, (v) spatial range shifts, (vi) adaptation and thermal resilience, (vii) sea ice related biological fluctuations, (viii) pollution, (ix) endangered terrestrial endemism and (x) the discovery of unknown habitats. Most Antarctic biotas are exposed to multiple stresses and considered vulnerable to environmental change due to narrow tolerance ranges, rapid change, projected circumpolar impacts, low potential for timely genetic adaptation, and migration barriers. Important ecosystem functions, such as primary production and energy transfer between trophic levels, have already changed, and biodiversity patterns have shifted. A confidence assessment of the degree of 'scientific understanding' revealed an intermediate level for most of the more detailed sub-messages, indicating that process-oriented research has been successful in the past decade. Additional efforts are necessary, however, to achieve the level of robustness in scientific knowledge that is required to inform protection measures of the unique Antarctic terrestrial and marine ecosystems, and their contributions to global biodiversity and ecosystem services.
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Affiliation(s)
- Julian Gutt
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Columbusstr., Bremerhaven, 27568, Germany
| | - Enrique Isla
- Institute of Marine Sciences-CSIC, Passeig Maritim de la Barceloneta 37-49, Barcelona, 08003, Spain
| | - José C Xavier
- University of Coimbra, MARE - Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, Coimbra, Portugal.,British Antarctic Survey, Natural Environmental Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, U.K
| | - Byron J Adams
- Department of Biology and Monte L. Bean Museum, Brigham Young University, Provo, UT, U.S.A
| | - In-Young Ahn
- Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon, 21990, South Korea
| | - C-H Christina Cheng
- Department of Evolution, Ecology and Behavior, University of Illinois, Urbana, IL, U.S.A
| | - Claudia Colesie
- School of GeoSciences, University of Edinburgh, Alexander Crum Brown Road, Edinburgh, EH9 3FF, U.K
| | - Vonda J Cummings
- National Institute of Water and Atmosphere Research Ltd (NIWA), 301 Evans Bay Parade, Greta Point, Wellington, New Zealand
| | - Guido di Prisco
- Institute of Biosciences and BioResources (IBBR), National Research Council (CNR), Via Pietro Castellino 111, Naples, I-80131, Italy
| | - Huw Griffiths
- British Antarctic Survey, Natural Environmental Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, U.K
| | - Ian Hawes
- Coastal Marine Field Station, University of Waikato, 58 Cross Road, Tauranga, 3100, New Zealand
| | - Ian Hogg
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand.,Canadian High Antarctic Research Station, Polar Knowledge Canada, PO Box 2150, Cambridge Bay, NU, X0B 0C0, Canada
| | - Trevor McIntyre
- Department of Life and Consumer Sciences, University of South Africa, Private Bag X6, Florida, 1710, South Africa
| | - Klaus M Meiners
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, and Australian Antarctic Program Partnership, University of Tasmania, 20 Castray Esplanade, Battery Point, TAS, 7004, Australia
| | - David A Pearce
- British Antarctic Survey, Natural Environmental Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, U.K.,Department of Applied Sciences, Faculty of Health and Life Sciences, Northumbria University at Newcastle, Northumberland Road, Newcastle upon Tyne, NE1 8ST, U.K
| | - Lloyd Peck
- British Antarctic Survey, Natural Environmental Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, U.K
| | - Dieter Piepenburg
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Columbusstr., Bremerhaven, 27568, Germany
| | - Ryan R Reisinger
- Centre d'Etudes Biologique de Chizé, UMR 7372 du Centre National de la Recherche Scientifique - La Rochelle Université, Villiers-en-Bois, 79360, France
| | - Grace K Saba
- Center for Ocean Observing Leadership, Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Rd., New Brunswick, NJ, 08901, U.S.A
| | - Irene R Schloss
- Instituto Antártico Argentino, Buenos Aires, Argentina.,Centro Austral de Investigaciones Científicas, Bernardo Houssay 200, Ushuaia, Tierra del Fuego, CP V9410CAB, Argentina.,Universidad Nacional de Tierra del Fuego, Ushuaia, Tierra del Fuego, CP V9410CAB, Argentina
| | - Camila N Signori
- Oceanographic Institute, University of São Paulo, Praça do Oceanográfico, 191, São Paulo, CEP: 05508-900, Brazil
| | - Craig R Smith
- Department of Oceanography, University of Hawaii at Manoa, 1000 Pope Road, Honolulu, HI, 96822, U.S.A
| | - Marino Vacchi
- Institute for the Study of the Anthropic Impacts and the Sustainability of the Marine Environment (IAS), National Research Council of Italy (CNR), Via de Marini 6, Genoa, 16149, Italy
| | - Cinzia Verde
- Institute of Biosciences and BioResources (IBBR), National Research Council (CNR), Via Pietro Castellino 111, Naples, I-80131, Italy
| | - Diana H Wall
- Department of Biology and School of Global Environmental Sustainability, Colorado State University, Fort Collins, CO, U.S.A
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Abstract
A unique environment at Borup Fiord Pass is characterized by a sulfur-enriched glacial ecosystem in the low-temperature Canadian High Arctic. BFP represents one of the best terrestrial analog sites for studying icy, sulfur-rich worlds outside our own, such as Europa and Mars. The site also allows investigation of sulfur-based microbial metabolisms in cold environments here on Earth. Here, we report whole-genome sequencing data that suggest that sulfur cycling metabolisms at BFP are more widely used across bacterial taxa than predicted. From our analyses, the metabolic capability of sulfur oxidation among multiple community members appears likely due to functional redundancy present in their genomes. Functional redundancy, with respect to sulfur-oxidation at the BFP sulfur-ice environment, may indicate that this dynamic ecosystem hosts microorganisms that are able to use multiple sulfur electron donors alongside other metabolic pathways, including those for carbon and nitrogen. Biological sulfur cycling in polar, low-temperature ecosystems is an understudied phenomenon in part due to difficulty of access and the dynamic nature of glacial environments. One such environment where sulfur cycling is known to play an important role in microbial metabolisms is located at Borup Fiord Pass (BFP) in the Canadian High Arctic. Here, transient springs emerge from ice near the terminus of a glacier, creating a large area of proglacial aufeis (spring-derived ice) that is often covered in bright yellow/white sulfur, sulfate, and carbonate mineral precipitates accompanied by a strong odor of hydrogen sulfide. Metagenomic sequencing of samples from multiple sites and of various sample types across the BFP glacial system produced 31 metagenome-assembled genomes (MAGs) that were queried for sulfur, nitrogen, and carbon cycling/metabolism genes. An abundance of sulfur cycling genes was widespread across the isolated MAGs and sample metagenomes taxonomically associated with the bacterial classes Alphaproteobacteria and Gammaproteobacteria and Campylobacteria (formerly the Epsilonproteobacteria). This corroborates previous research from BFP implicating Campylobacteria as the primary class responsible for sulfur oxidation; however, data reported here suggested putative sulfur oxidation by organisms in both the alphaproteobacterial and gammaproteobacterial classes that was not predicted by previous work. These findings indicate that in low-temperature, sulfur-based environments, functional redundancy may be a key mechanism that microorganisms use to enable coexistence whenever energy is limited and/or focused by redox chemistry. IMPORTANCE A unique environment at Borup Fiord Pass is characterized by a sulfur-enriched glacial ecosystem in the low-temperature Canadian High Arctic. BFP represents one of the best terrestrial analog sites for studying icy, sulfur-rich worlds outside our own, such as Europa and Mars. The site also allows investigation of sulfur-based microbial metabolisms in cold environments here on Earth. Here, we report whole-genome sequencing data that suggest that sulfur cycling metabolisms at BFP are more widely used across bacterial taxa than predicted. From our analyses, the metabolic capability of sulfur oxidation among multiple community members appears likely due to functional redundancy present in their genomes. Functional redundancy, with respect to sulfur-oxidation at the BFP sulfur-ice environment, may indicate that this dynamic ecosystem hosts microorganisms that are able to use multiple sulfur electron donors alongside other metabolic pathways, including those for carbon and nitrogen.
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10
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Subglacial meltwater supported aerobic marine habitats during Snowball Earth. Proc Natl Acad Sci U S A 2019; 116:25478-25483. [PMID: 31792178 DOI: 10.1073/pnas.1909165116] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Earth's most severe ice ages interrupted a crucial interval in eukaryotic evolution with widespread ice coverage during the Cryogenian Period (720 to 635 Ma). Aerobic eukaryotes must have survived the "Snowball Earth" glaciations, requiring the persistence of oxygenated marine habitats, yet evidence for these environments is lacking. We examine iron formations within globally distributed Cryogenian glacial successions to reconstruct the redox state of the synglacial oceans. Iron isotope ratios and cerium anomalies from a range of glaciomarine environments reveal pervasive anoxia in the ice-covered oceans but increasing oxidation with proximity to the ice shelf grounding line. We propose that the outwash of subglacial meltwater supplied oxygen to the synglacial oceans, creating glaciomarine oxygen oases. The confluence of oxygen-rich meltwater and iron-rich seawater may have provided sufficient energy to sustain chemosynthetic communities. These processes could have supplied the requisite oxygen and organic carbon source for the survival of early animals and other eukaryotic heterotrophs through these extreme glaciations.
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11
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Margesin R, Collins T. Microbial ecology of the cryosphere (glacial and permafrost habitats): current knowledge. Appl Microbiol Biotechnol 2019; 103:2537-2549. [PMID: 30719551 PMCID: PMC6443599 DOI: 10.1007/s00253-019-09631-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/04/2019] [Accepted: 01/07/2019] [Indexed: 11/28/2022]
Abstract
Microorganisms in cold ecosystems play a key ecological role in their natural habitats. Since these ecosystems are especially sensitive to climate changes, as indicated by the worldwide retreat of glaciers and ice sheets as well as permafrost thawing, an understanding of the role and potential of microbial life in these habitats has become crucial. Emerging technologies have added significantly to our knowledge of abundance, functional activity, and lifestyles of microbial communities in cold environments. The current knowledge of microbial ecology in glacial habitats and permafrost, the most studied habitats of the cryosphere, is reported in this review.
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Affiliation(s)
- Rosa Margesin
- Institute of Microbiology, University of Innsbruck, 6020, Innsbruck, Austria.
| | - Tony Collins
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710-057, Braga, Portugal
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12
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Jones RM, Goordial JM, Orcutt BN. Low Energy Subsurface Environments as Extraterrestrial Analogs. Front Microbiol 2018; 9:1605. [PMID: 30072971 PMCID: PMC6058055 DOI: 10.3389/fmicb.2018.01605] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/27/2018] [Indexed: 11/13/2022] Open
Abstract
Earth's subsurface is often isolated from phototrophic energy sources and characterized by chemotrophic modes of life. These environments are often oligotrophic and limited in electron donors or electron acceptors, and include continental crust, subseafloor oceanic crust, and marine sediment as well as subglacial lakes and the subsurface of polar desert soils. These low energy subsurface environments are therefore uniquely positioned for examining minimum energetic requirements and adaptations for chemotrophic life. Current targets for astrobiology investigations of extant life are planetary bodies with largely inhospitable surfaces, such as Mars, Europa, and Enceladus. Subsurface environments on Earth thus serve as analogs to explore possibilities of subsurface life on extraterrestrial bodies. The purpose of this review is to provide an overview of subsurface environments as potential analogs, and the features of microbial communities existing in these low energy environments, with particular emphasis on how they inform the study of energetic limits required for life. The thermodynamic energetic calculations presented here suggest that free energy yields of reactions and energy density of some metabolic redox reactions on Mars, Europa, Enceladus, and Titan could be comparable to analog environments in Earth's low energy subsurface habitats.
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Affiliation(s)
| | | | - Beth N. Orcutt
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
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13
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Kayani MUR, Doyle SM, Sangwan N, Wang G, Gilbert JA, Christner BC, Zhu TF. Metagenomic analysis of basal ice from an Alaskan glacier. MICROBIOME 2018; 6:123. [PMID: 29976249 PMCID: PMC6034282 DOI: 10.1186/s40168-018-0505-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 06/18/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Glaciers cover ~ 10% of land but are among the least explored environments on Earth. The basal portion of glaciers often harbors unique aquatic microbial ecosystems in the absence of sunlight, and knowledge on the microbial community structures and their metabolic potential is very limited. Here, we provide insights into the microbial lifestyle present at the base of the Matanuska Glacier, Alaska. RESULTS DNA and RNA were extracted from samples of the Matanuska Glacier basal ice. Using Illumina MiSeq and HiSeq sequencing, we investigated the microbial diversity with the metagenomic shotgun reads and 16S ribosomal RNA data. We further assembled 9 partial and draft bacterial genomes from the metagenomic assembly, and identified key metabolic pathways such as sulfur oxidation and nitrification. Collectively, our analyses suggest a prevalence of lithotrophic and heterotrophic metabolisms in the subglacial microbiome. CONCLUSION Our results present the first metagenomic assembly and bacterial draft genomes for a subglacial environment. These results extend our understanding of the chemical and biological processes in subglacial environments critically influenced by global climate change.
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Affiliation(s)
- Masood Ur Rehman Kayani
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Synthetic and Systems Biology, Ministry of Education Key Laboratory of Bioinformatics, Tsinghua University, Beijing, 100084, China
| | - Shawn M Doyle
- College of Geosciences, Texas A&M University, College Station, TX, 77843, USA
| | - Naseer Sangwan
- Biosciences Division (BIO), Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA
- Department of Surgery, The Microbiome Center, University of Chicago, 5841 South Maryland Avenue, MC 5029, Chicago, IL, 60637, USA
| | - Guanqun Wang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Synthetic and Systems Biology, Ministry of Education Key Laboratory of Bioinformatics, Tsinghua University, Beijing, 100084, China
| | - Jack A Gilbert
- Biosciences Division (BIO), Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA.
- Department of Surgery, The Microbiome Center, University of Chicago, 5841 South Maryland Avenue, MC 5029, Chicago, IL, 60637, USA.
- The Microbiome Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA.
| | - Brent C Christner
- Department of Microbiology and Cell Science, Biodiversity Institute, University of Florida, Gainesville, FL, 32611, USA.
| | - Ting F Zhu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Synthetic and Systems Biology, Ministry of Education Key Laboratory of Bioinformatics, Tsinghua University, Beijing, 100084, China.
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14
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Madigan MT, Kempher ML, Bender KS, Sullivan P, Matthew Sattley W, Dohnalkova AC, Joye SB. Characterization of a cold-active bacterium isolated from the South Pole "Ice Tunnel". Extremophiles 2017; 21:891-901. [PMID: 28681112 DOI: 10.1007/s00792-017-0950-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 06/23/2017] [Indexed: 11/26/2022]
Abstract
Extremely cold microbial habitats on Earth (those below -30 °C) are rare and have not been surveyed for microbes as extensively as environments in the 0 to -20 °C range. Using cryoprotected growth media incubated at -5 °C, we enriched a cold-active Pseudomonas species from -50 °C ice collected from a utility tunnel for wastewater pipes under Amundsen-Scott South Pole Station, Antarctica. The isolate, strain UC-1, is related to other cold-active Pseudomonas species, most notably P. psychrophila, and grew at -5 °C to +34-37 °C; growth of UC-1 at +3 °C was significantly faster than at +34 °C. Strain UC-1 synthesized a surface exopolymer and high levels of unsaturated fatty acids under cold growth conditions. A 16S rRNA gene diversity screen of the ice sample that yielded strain UC-1 revealed over 1200 operational taxonomic units (OTUs) distributed across eight major classes of Bacteria. Many of the OTUs were Clostridia and Bacteriodia and some of these were probably of wastewater origin. However, a significant fraction of the OTUs were Proteobacteria and Actinobacteria of likely environmental origin. Our results shed light on the lower temperature limits to life and the possible existence of functional microbial communities in ultra-cold environments.
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Affiliation(s)
- Michael T Madigan
- Department of Microbiology, Southern Illinois University, Carbondale, IL, 62901, USA.
| | - Megan L Kempher
- Department of Microbiology, Southern Illinois University, Carbondale, IL, 62901, USA
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Kelly S Bender
- Department of Microbiology, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Paul Sullivan
- United States Antarctic Program, Amundsen-Scott Station, Antarctica
| | - W Matthew Sattley
- Division of Natural Sciences, Indiana Wesleyan University, Marion, IN, 46953, USA
| | | | - Samantha B Joye
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
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15
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Anesio AM, Lutz S, Chrismas NAM, Benning LG. The microbiome of glaciers and ice sheets. NPJ Biofilms Microbiomes 2017; 3:10. [PMID: 28649411 PMCID: PMC5460203 DOI: 10.1038/s41522-017-0019-0] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/17/2017] [Accepted: 03/23/2017] [Indexed: 01/09/2023] Open
Abstract
Glaciers and ice sheets, like other biomes, occupy a significant area of the planet and harbour biological communities with distinct interactions and feedbacks with their physical and chemical environment. In the case of the glacial biome, the biological processes are dominated almost exclusively by microbial communities. Habitats on glaciers and ice sheets with enough liquid water to sustain microbial activity include snow, surface ice, cryoconite holes, englacial systems and the interface between ice and overridden rock/soil. There is a remarkable similarity between the different specific glacial habitats across glaciers and ice sheets worldwide, particularly regarding their main primary producers and ecosystem engineers. At the surface, cyanobacteria dominate the carbon production in aquatic/sediment systems such as cryoconite holes, while eukaryotic Zygnematales and Chlamydomonadales dominate ice surfaces and snow dynamics, respectively. Microbially driven chemolithotrophic processes associated with sulphur and iron cycle and C transformations in subglacial ecosystems provide the basis for chemical transformations at the rock interface under the ice that underpin an important mechanism for the delivery of nutrients to downstream ecosystems. In this review, we focus on the main ecosystem engineers of glaciers and ice sheets and how they interact with their chemical and physical environment. We then discuss the implications of this microbial activity on the icy microbiome to the biogeochemistry of downstream ecosystems.
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Affiliation(s)
- Alexandre M. Anesio
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS UK
| | - Stefanie Lutz
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Nathan A. M. Chrismas
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS UK
| | - Liane G. Benning
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
- Department of Earth Sciences, Free University of Berlin, 12249 Berlin, Germany
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16
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Vick-Majors TJ, Mitchell AC, Achberger AM, Christner BC, Dore JE, Michaud AB, Mikucki JA, Purcell AM, Skidmore ML, Priscu JC. Physiological Ecology of Microorganisms in Subglacial Lake Whillans. Front Microbiol 2016; 7:1705. [PMID: 27833599 PMCID: PMC5081474 DOI: 10.3389/fmicb.2016.01705] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/12/2016] [Indexed: 11/13/2022] Open
Abstract
Subglacial microbial habitats are widespread in glaciated regions of our planet. Some of these environments have been isolated from the atmosphere and from sunlight for many thousands of years. Consequently, ecosystem processes must rely on energy gained from the oxidation of inorganic substrates or detrital organic matter. Subglacial Lake Whillans (SLW) is one of more than 400 subglacial lakes known to exist under the Antarctic ice sheet; however, little is known about microbial physiology and energetics in these systems. When it was sampled through its 800 m thick ice cover in 2013, the SLW water column was shallow (~2 m deep), oxygenated, and possessed sufficient concentrations of C, N, and P substrates to support microbial growth. Here, we use a combination of physiological assays and models to assess the energetics of microbial life in SLW. In general, SLW microorganisms grew slowly in this energy-limited environment. Heterotrophic cellular carbon turnover times, calculated from 3H-thymidine and 3H-leucine incorporation rates, were long (60 to 500 days) while cellular doubling times averaged 196 days. Inferred growth rates (average ~0.006 d-1) obtained from the same incubations were at least an order of magnitude lower than those measured in Antarctic surface lakes and oligotrophic areas of the ocean. Low growth efficiency (8%) indicated that heterotrophic populations in SLW partition a majority of their carbon demand to cellular maintenance rather than growth. Chemoautotrophic CO2-fixation exceeded heterotrophic organic C-demand by a factor of ~1.5. Aerobic respiratory activity associated with heterotrophic and chemoautotrophic metabolism surpassed the estimated supply of oxygen to SLW, implying that microbial activity could deplete the oxygenated waters, resulting in anoxia. We used thermodynamic calculations to examine the biogeochemical and energetic consequences of environmentally imposed switching between aerobic and anaerobic metabolisms in the SLW water column. Heterotrophic metabolisms utilizing acetate and formate as electron donors yielded less energy than chemolithotrophic metabolisms when calculated in terms of energy density, which supports experimental results that showed chemoautotrophic activity in excess of heterotrophic activity. The microbial communities of subglacial lake ecosystems provide important natural laboratories to study the physiological and biogeochemical behavior of microorganisms inhabiting cold, dark environments.
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Affiliation(s)
- Trista J Vick-Majors
- Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - Andrew C Mitchell
- Department of Geography and Earth Sciences, Aberystwyth University Aberystwyth, UK
| | - Amanda M Achberger
- Department of Biological Sciences, Louisiana State University Baton Rouge, LA, USA
| | - Brent C Christner
- Department of Microbiology and Cell Science, University of FloridaGainesville, FL, USA; Biodiversity Institute, University of FloridaGainesville, FL, USA
| | - John E Dore
- Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - Alexander B Michaud
- Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - Jill A Mikucki
- Department of Microbiology, University of Tennessee Knoxville, TN, USA
| | - Alicia M Purcell
- Department of Microbiology, University of Tennessee Knoxville, TN, USA
| | - Mark L Skidmore
- Department of Earth Sciences, Montana State University Bozeman, MT, USA
| | - John C Priscu
- Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
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17
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Siegert MJ, Priscu JC, Alekhina IA, Wadham JL, Lyons WB. Antarctic subglacial lake exploration: first results and future plans. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2014.0466. [PMID: 26667917 PMCID: PMC4685969 DOI: 10.1098/rsta.2014.0466] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/07/2015] [Indexed: 06/05/2023]
Abstract
After more than a decade of planning, three attempts were made in 2012-2013 to access, measure in situ properties and directly sample subglacial Antarctic lake environments. First, Russian scientists drilled into the top of Lake Vostok, allowing lake water to infiltrate, and freeze within, the lower part of the ice-core borehole, from which further coring would recover a frozen sample of surface lake water. Second, UK engineers tried unsuccessfully to deploy a clean-access hot-water drill, to sample the water column and sediments of subglacial Lake Ellsworth. Third, a US mission successfully drilled cleanly into subglacial Lake Whillans, a shallow hydraulically active lake at the coastal margin of West Antarctica, obtaining samples that would later be used to prove the existence of microbial life and active biogeochemical cycling beneath the ice sheet. This article summarizes the results of these programmes in terms of the scientific results obtained, the operational knowledge gained and the engineering challenges revealed, to collate what is known about Antarctic subglacial environments and how to explore them in future. While results from Lake Whillans testify to subglacial lakes as being viable biological habitats, the engineering challenges to explore deeper more isolated lakes where unique microorganisms and climate records may be found, as exemplified in the Lake Ellsworth and Vostok missions, are considerable. Through international cooperation, and by using equipment and knowledge of the existing subglacial lake exploration programmes, it is possible that such environments could be explored thoroughly, and at numerous sites, in the near future.
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Affiliation(s)
- Martin J Siegert
- Grantham Institute and Department of Earth Science and Engineering, Imperial College London, London, South Kensington, UK
| | - John C Priscu
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | | | - Jemma L Wadham
- School of Geographical Sciences, University of Bristol, Bristol, UK
| | - W Berry Lyons
- School of Earth Sciences, Ohio State University, Columbus, OH, USA
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18
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McKay RM, Barrett PJ, Levy RS, Naish TR, Golledge NR, Pyne A. Antarctic Cenozoic climate history from sedimentary records: ANDRILL and beyond. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2014.0301. [PMID: 26667911 DOI: 10.1098/rsta.2014.0301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/20/2015] [Indexed: 06/05/2023]
Abstract
Mounting evidence from models and geological data implies that the Antarctic Ice Sheet may behave in an unstable manner and retreat rapidly in response to a warming climate, which is a key factor motivating efforts to improve estimates of Antarctic ice volume contributions to future sea-level rise. Here, we review Antarctic cooling history since peak temperatures of the Middle Eocene Climatic Optimum (approx. 50 Ma) to provide a framework for future initiatives to recover sediment cores from subglacial lakes and sedimentary basins in Antarctica's continental interior. While the existing inventory of cores has yielded important insights into the biotic and climatic evolution of Antarctica, strata have numerous and often lengthy time breaks, providing a framework of 'snapshots' through time. Further cores, and more work on existing cores, are needed to reconcile Antarctic records with the more continuous 'far-field' records documenting the evolution of global ice volume and deep-sea temperature. To achieve this, we argue for an integrated portfolio of drilling and coring missions that encompasses existing methodologies using ship- and sea-ice-/ice-shelf-based drilling platforms as well as recently developed seafloor-based drilling and subglacial access systems. We conclude by reviewing key technological issues that will need to be overcome.
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Affiliation(s)
- R M McKay
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
| | - P J Barrett
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
| | - R S Levy
- GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand
| | - T R Naish
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand
| | - N R Golledge
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand
| | - A Pyne
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
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