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Strock KE, Krewson RB, Hayes NM, Deemer BR. Oxidation is a potentially significant methane sink in land-terminating glacial runoff. Sci Rep 2024; 14:23389. [PMID: 39379398 PMCID: PMC11461896 DOI: 10.1038/s41598-024-73041-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Accepted: 09/12/2024] [Indexed: 10/10/2024] Open
Abstract
Globally, aquatic ecosystems are one of the largest but most uncertain sources of methane, a potent greenhouse gas. It is unclear how climate change will affect methane emissions, but recent work suggests that glacial systems, which are melting faster with climate change, may be an important source of methane to the atmosphere. Currently, studies quantifying glacial emissions are limited in number, and the role of methanotrophy, or microbial methane oxidizers, in reducing atmospheric emissions from source and receiving waters is not well known. Here we discuss three potential sites for methane oxidation that could mitigate emissions from glaciers into the atmosphere: under ice oxidation, oxidation within proglacial lakes, and oxidation within melt rivers. The research presented here increases the number of glacial sites with methane concentration data and is one of only a few studies to quantify the net microbial activity of methane production and oxidation in two types of land-terminating glacial runoff (lake and river). We find that oxidation in a glacial river may reduce atmospheric methane emissions from glacial melt by as much as 53%. Incorporating methane oxidation in estimates of glacial methane emissions may significantly reduce the estimated magnitude of this source in budgeting exercises.
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Affiliation(s)
- Kristin E Strock
- Environmental Science Department, Dickinson College, Carlisle, PA, 17013, USA.
| | - Rachel B Krewson
- Environmental Science Department, Dickinson College, Carlisle, PA, 17013, USA
| | - Nicole M Hayes
- Biology Department, University of Wisconsin Stout, Menomonie, WI, 54751, USA
| | - Bridget R Deemer
- US Geological Survey, Southwest Biological Science Center, Flagstaff, AZ, 86001, USA
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2
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Feng M, Robinson S, Qi W, Edwards A, Stierli B, van der Heijden M, Frey B, Varliero G. Microbial genetic potential differs among cryospheric habitats of the Damma glacier. Microb Genom 2024; 10. [PMID: 39351905 PMCID: PMC11443553 DOI: 10.1099/mgen.0.001301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2024] Open
Abstract
Climate warming has led to glacier retreat worldwide. Studies on the taxonomy and functions of glacier microbiomes help us better predict their response to glacier melting. Here, we used shotgun metagenomic sequencing to study the microbial functional potential in different cryospheric habitats, i.e. surface snow, supraglacial and subglacial sediments, subglacial ice, proglacial stream water and recently deglaciated soils. The functional gene structure varied greatly among habitats, especially for snow, which differed significantly from all other habitats. Differential abundance analysis revealed that genes related to stress responses (e.g. chaperones) were enriched in ice habitat, supporting the fact that glaciers are a harsh environment for microbes. The microbial metabolic capabilities related to carbon and nitrogen cycling vary among cryospheric habitats. Genes related to auxiliary activities were overrepresented in the subglacial sediment, suggesting a higher genetic potential for the degradation of recalcitrant carbon (e.g., lignin). As for nitrogen cycling, genes related to nitrogen fixation were more abundant in barren proglacial soils, possibly due to the presence of Cyanobacteriota in this habitat. Our results deepen our understanding of microbial processes in glacial ecosystems, which are vulnerable to ongoing global warming, and they have implications for downstream ecosystems.
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Affiliation(s)
- Maomao Feng
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Serina Robinson
- Department of Environmental Microbiology, Swiss Federal Research Institute of Aquatic Science and Technology (EAWAG), Dübendorf, Switzerland
| | - Weihong Qi
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
- Swiss Institute of Bioinformatics (SIB), Geneva, Switzerland
| | - Arwyn Edwards
- Department of Life Sciences (DLS), Aberystwyth University, Wales, UK
| | - Beat Stierli
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Marcel van der Heijden
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
- Plant-Soil Interactions, Agroscope, Zurich, Switzerland
| | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Gilda Varliero
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
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3
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Konya K, Sueyoshi T, Iwahana G, Morishita T, Uetake J, Wakita M. CH 4 emissions from runoff water of Alaskan mountain glaciers. Sci Rep 2024; 14:10558. [PMID: 38724590 PMCID: PMC11082196 DOI: 10.1038/s41598-024-56608-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 03/08/2024] [Indexed: 05/12/2024] Open
Abstract
Recent studies have observed high methane concentrations in runoff water and the ambient air at various glacier sites, including the Greenland Ice Sheet, the glacier forefield in Svalbard, and the ice cap in Iceland. This study extends these findings to smaller mountain glaciers in Alaska. Methane and carbon dioxide concentrations in the ambient air near the meltwater outlet, fluxes of these gases at the surface of runoff water and riverbank sediments, and dissolved methane content in the runoff water were measured at four glaciers. Three of the four glaciers showed conspicuous signals of methane emissions from runoff water, with the Castner Glacier terminus exhibiting a methane concentration three times higher than background levels, along with elevated dissolved methane levels in the runoff water. This study marks the detection of significant methane emissions from small mountain glacier runoff, contributing to the understanding that mountain glaciers also release methane into the atmosphere.
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Affiliation(s)
- Keiko Konya
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, 236-0001, Japan
| | - Tetsuo Sueyoshi
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, 236-0001, Japan.
- National Institute of Polar Research, Tachikawa, 190-8518, Japan.
| | - Go Iwahana
- International Arctic Research Center (IARC), University of Alaska, Fairbanks (UAF), Fairbanks, 99775, USA
| | - Tomoaki Morishita
- Tohoku Research Center, Forestry and Forest Products Research Institute (FFPRI), Morioka, 020-0123, Japan
| | - Jun Uetake
- Hokkaido University, Field Science Center for Northern Biosphere, Tomakomai, 053-0035, Japan
| | - Masahide Wakita
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Mutsu, 035-0022, Japan
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4
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Znamínko M, Falteisek L, Vrbická K, Klímová P, Christiansen JR, Jørgensen CJ, Stibal M. Methylotrophic Communities Associated with a Greenland Ice Sheet Methane Release Hotspot. MICROBIAL ECOLOGY 2023; 86:3057-3067. [PMID: 37843656 PMCID: PMC10640400 DOI: 10.1007/s00248-023-02302-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 09/09/2023] [Indexed: 10/17/2023]
Abstract
Subglacial environments provide conditions suitable for the microbial production of methane, an important greenhouse gas, which can be released from beneath the ice as a result of glacial melting. High gaseous methane emissions have recently been discovered at Russell Glacier, an outlet of the southwestern margin of the Greenland Ice Sheet, acting not only as a potential climate amplifier but also as a substrate for methane consuming microorganisms. Here, we describe the composition of the microbial assemblage exported in meltwater from the methane release hotspot at Russell Glacier and its changes over the melt season and as it travels downstream. We found that a substantial part (relative abundance 27.2% across the whole dataset) of the exported assemblage was made up of methylotrophs and that the relative abundance of methylotrophs increased as the melt season progressed, likely due to the seasonal development of the glacial drainage system. The methylotrophs were dominated by representatives of type I methanotrophs from the Gammaproteobacteria; however, their relative abundance decreased with increasing distance from the ice margin at the expense of type II methanotrophs and/or methylotrophs from the Alphaproteobacteria and Betaproteobacteria. Our results show that subglacial methane release hotspot sites can be colonized by microorganisms that can potentially reduce methane emissions.
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Affiliation(s)
- Matěj Znamínko
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia.
- Current address: Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
| | - Lukáš Falteisek
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Kristýna Vrbická
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Petra Klímová
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Jesper R Christiansen
- Department of Geoscience and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | | | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia.
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5
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Řezanka T, Kyselová L, Murphy DJ. Archaeal lipids. Prog Lipid Res 2023; 91:101237. [PMID: 37236370 DOI: 10.1016/j.plipres.2023.101237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/25/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023]
Abstract
The major archaeal membrane glycerolipids are distinguished from those of bacteria and eukaryotes by the contrasting stereochemistry of their glycerol backbones, and by the use of ether-linked isoprenoid-based alkyl chains rather than ester-linked fatty acyl chains for their hydrophobic moieties. These fascinating compounds play important roles in the extremophile lifestyles of many species, but are also present in the growing numbers of recently discovered mesophilic archaea. The past decade has witnessed significant advances in our understanding of archaea in general and their lipids in particular. Much of the new information has come from the ability to screen large microbial populations via environmental metagenomics, which has revolutionised our understanding of the extent of archaeal biodiversity that is coupled with a strict conservation of their membrane lipid compositions. Significant additional progress has come from new culturing and analytical techniques that are gradually enabling archaeal physiology and biochemistry to be studied in real time. These studies are beginning to shed light on the much-discussed and still-controversial process of eukaryogenesis, which probably involved both bacterial and archaeal progenitors. Puzzlingly, although eukaryotes retain many attributes of their putative archaeal ancestors, their lipid compositions only reflect their bacterial progenitors. Finally, elucidation of archaeal lipids and their metabolic pathways have revealed potentially interesting applications that have opened up new frontiers for biotechnological exploitation of these organisms. This review is concerned with the analysis, structure, function, evolution and biotechnology of archaeal lipids and their associated metabolic pathways.
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Affiliation(s)
- Tomáš Řezanka
- Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, 142 00 Prague, Czech Republic
| | - Lucie Kyselová
- Research Institute of Brewing and Malting, Lípová 511, 120 44 Prague, Czech Republic
| | - Denis J Murphy
- School of Applied Sciences, University of South Wales, Pontypridd, CF37 1DL, United Kingdom.
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6
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Tveit AT, Söllinger A, Rainer EM, Didriksen A, Hestnes AG, Motleleng L, Hellinger HJ, Rattei T, Svenning MM. Thermal acclimation of methanotrophs from the genus Methylobacter. THE ISME JOURNAL 2023; 17:502-513. [PMID: 36650275 PMCID: PMC10030640 DOI: 10.1038/s41396-023-01363-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/30/2022] [Accepted: 01/10/2023] [Indexed: 01/19/2023]
Abstract
Methanotrophs oxidize most of the methane (CH4) produced in natural and anthropogenic ecosystems. Often living close to soil surfaces, these microorganisms must frequently adjust to temperature change. While many environmental studies have addressed temperature effects on CH4 oxidation and methanotrophic communities, there is little knowledge about the physiological adjustments that underlie these effects. We have studied thermal acclimation in Methylobacter, a widespread, abundant, and environmentally important methanotrophic genus. Comparisons of growth and CH4 oxidation kinetics at different temperatures in three members of the genus demonstrate that temperature has a strong influence on how much CH4 is consumed to support growth at different CH4 concentrations. However, the temperature effect varies considerably between species, suggesting that how a methanotrophic community is composed influences the temperature effect on CH4 uptake. To understand thermal acclimation mechanisms widely we carried out a transcriptomics experiment with Methylobacter tundripaludum SV96T. We observed, at different temperatures, how varying abundances of transcripts for glycogen and protein biosynthesis relate to cellular glycogen and ribosome concentrations. Our data also demonstrated transcriptional adjustment of CH4 oxidation, oxidative phosphorylation, membrane fatty acid saturation, cell wall composition, and exopolysaccharides between temperatures. In addition, we observed differences in M. tundripaludum SV96T cell sizes at different temperatures. We conclude that thermal acclimation in Methylobacter results from transcriptional adjustment of central metabolism, protein biosynthesis, cell walls and storage. Acclimation leads to large shifts in CH4 consumption and growth efficiency, but with major differences between species. Thus, our study demonstrates that physiological adjustments to temperature change can substantially influence environmental CH4 uptake rates and that consideration of methanotroph physiology might be vital for accurate predictions of warming effects on CH4 emissions.
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Affiliation(s)
- Alexander T Tveit
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.
| | - Andrea Söllinger
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Edda Marie Rainer
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Alena Didriksen
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Anne Grethe Hestnes
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Liabo Motleleng
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Hans-Jörg Hellinger
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
- University of Vienna, Doctoral School in Microbiology and Environmental Science, Vienna, Austria
| | - Thomas Rattei
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
| | - Mette M Svenning
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
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7
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Davis CL, Venturelli RA, Michaud AB, Hawkings JR, Achberger AM, Vick-Majors TJ, Rosenheim BE, Dore JE, Steigmeyer A, Skidmore ML, Barker JD, Benning LG, Siegfried MR, Priscu JC, Christner BC. Biogeochemical and historical drivers of microbial community composition and structure in sediments from Mercer Subglacial Lake, West Antarctica. ISME COMMUNICATIONS 2023; 3:8. [PMID: 36717625 PMCID: PMC9886901 DOI: 10.1038/s43705-023-00216-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/24/2022] [Accepted: 01/13/2023] [Indexed: 02/01/2023]
Abstract
Ice streams that flow into Ross Ice Shelf are underlain by water-saturated sediments, a dynamic hydrological system, and subglacial lakes that intermittently discharge water downstream across grounding zones of West Antarctic Ice Sheet (WAIS). A 2.06 m composite sediment profile was recently recovered from Mercer Subglacial Lake, a 15 m deep water cavity beneath a 1087 m thick portion of the Mercer Ice Stream. We examined microbial abundances, used 16S rRNA gene amplicon sequencing to assess community structures, and characterized extracellular polymeric substances (EPS) associated with distinct lithologic units in the sediments. Bacterial and archaeal communities in the surficial sediments are more abundant and diverse, with significantly different compositions from those found deeper in the sediment column. The most abundant taxa are related to chemolithoautotrophs capable of oxidizing reduced nitrogen, sulfur, and iron compounds with oxygen, nitrate, or iron. Concentrations of dissolved methane and total organic carbon together with water content in the sediments are the strongest predictors of taxon and community composition. δ¹³C values for EPS (-25 to -30‰) are consistent with the primary source of carbon for biosynthesis originating from legacy marine organic matter. Comparison of communities to those in lake sediments under an adjacent ice stream (Whillans Subglacial Lake) and near its grounding zone provide seminal evidence for a subglacial metacommunity that is biogeochemically and evolutionarily linked through ice sheet dynamics and the transport of microbes, water, and sediments beneath WAIS.
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Affiliation(s)
- Christina L Davis
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
| | - Ryan A Venturelli
- Department of Geology and Geological Engineering, Colorado School of Mines, Golden, CO, USA
| | - Alexander B Michaud
- Center for Geomicrobiology, Aarhus University, Aarhus, DK, Denmark
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA
| | - Jon R Hawkings
- Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Amanda M Achberger
- Department of Oceanography, Texas A&M University, College Station, TX, USA
| | - Trista J Vick-Majors
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA
| | - Brad E Rosenheim
- College of Marine Sciences, University of South Florida, St. Petersburg, FL, USA
| | - John E Dore
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | - August Steigmeyer
- Department of Earth Sciences, Montana State University, Bozeman, MT, USA
| | - Mark L Skidmore
- Department of Earth Sciences, Montana State University, Bozeman, MT, USA
| | - Joel D Barker
- School of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Liane G Benning
- GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, Germany
- Department of Earth Sciences, Freie Universität Berlin, Berlin, Germany
| | - Matthew R Siegfried
- Hydrologic Science and Engineering Program, Department of Geophysics, Colorado School of Mines, Golden, CO, USA
| | | | - Brent C Christner
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA.
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8
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Vrbická K, Kohler TJ, Falteisek L, Hawkings JR, Vinšová P, Bulínová M, Lamarche-Gagnon G, Hofer S, Kellerman AM, Holt AD, Cameron KA, Schön M, Wadham JL, Stibal M. Catchment characteristics and seasonality control the composition of microbial assemblages exported from three outlet glaciers of the Greenland Ice Sheet. Front Microbiol 2022; 13:1035197. [PMID: 36523833 PMCID: PMC9745319 DOI: 10.3389/fmicb.2022.1035197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 11/09/2022] [Indexed: 10/17/2023] Open
Abstract
Glacial meltwater drains into proglacial rivers where it interacts with the surrounding landscape, collecting microbial cells as it travels downstream. Characterizing the composition of the resulting microbial assemblages in transport can inform us about intra-annual changes in meltwater flowpaths beneath the glacier as well as hydrological connectivity with proglacial areas. Here, we investigated how the structure of suspended microbial assemblages evolves over the course of a melt season for three proglacial catchments of the Greenland Ice Sheet (GrIS), reasoning that differences in glacier size and the proportion of glacierized versus non-glacierized catchment areas will influence both the identity and relative abundance of microbial taxa in transport. Streamwater samples were taken at the same time each day over a period of 3 weeks (summer 2018) to identify temporal patterns in microbial assemblages for three outlet glaciers of the GrIS, which differed in glacier size (smallest to largest; Russell, Leverett, and Isunnguata Sermia [IS]) and their glacierized: proglacial catchment area ratio (Leverett, 76; Isunnguata Sermia, 25; Russell, 2). DNA was extracted from samples, and 16S rRNA gene amplicons sequenced to characterize the structure of assemblages. We found that microbial diversity was significantly greater in Isunnguata Sermia and Russell Glacier rivers compared to Leverett Glacier, the latter of which having the smallest relative proglacial catchment area. Furthermore, the microbial diversity of the former two catchments continued to increase over monitored period, presumably due to increasing hydrologic connectivity with proglacial habitats. Meanwhile, diversity decreased over the monitored period in Leverett, which may have resulted from the evolution of an efficient subglacial drainage system. Linear discriminant analysis further revealed that bacteria characteristic to soils were disproportionately represented in the Isunnguata Sermia river, while putative methylotrophs were disproportionately abundant in Russell Glacier. Meanwhile, taxa typical for glacierized habitats (i.e., Rhodoferax and Polaromonas) dominated in the Leverett Glacier river. Our findings suggest that the proportion of deglaciated catchment area is more influential to suspended microbial assemblage structure than absolute glacier size, and improve our understanding of hydrological flowpaths, particulate entrainment, and transport.
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Affiliation(s)
- Kristýna Vrbická
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Tyler J. Kohler
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Lukáš Falteisek
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Jon R. Hawkings
- Department of Earth and Environment, University of Pennsylvania, Philadelphia, PA, United States
| | - Petra Vinšová
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Marie Bulínová
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
- Department of Geosciences, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Guillaume Lamarche-Gagnon
- Department of Geosciences, UiT, The Arctic University of Norway, Tromsø, Norway
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, United Kingdom
| | - Stefan Hofer
- Department of Geosciences, UiO University of Oslo, Oslo, Norway
| | - Anne M. Kellerman
- Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, United States
| | - Amy D. Holt
- Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, United States
| | - Karen A. Cameron
- School of Geographical & Earth Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Martina Schön
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Jemma L. Wadham
- Department of Geosciences, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
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9
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Liu Y, Xu Y, Cui X, Zhang B, Wang X, Qin X, Wang J, Li Y, Zhang W, Liu G, Chen T, Zhang G. Temporary Survival Increasing the Diversity of Culturable Heterotrophic Bacteria in the Newly Exposed Moraine at a Glacier Snout. BIOLOGY 2022; 11:biology11111555. [PMID: 36358257 PMCID: PMC9687651 DOI: 10.3390/biology11111555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 09/11/2022] [Accepted: 10/20/2022] [Indexed: 11/05/2022]
Abstract
Laohugou Glacier No. 12 is located on the northern slope of the western Qilian Mountains with a temperate continental wet climate and an extremely cold winter. Bacteria in a newly exposed moraine have to cope with various pressures owing to deglaciation at the glacier snout. However, limited information is available regarding the high diversity and temporary survival of culturable heterotrophic bacteria under various environmental stresses. To examine the tolerance of extremophiles against varying environmental conditions in a newly exposed moraine, we simulated environmental stress in bacterial cultures. The results showed that the isolated strains belonged to actinobacteria, Proteobacteria, Bacteroidetes, Deinococcus-Thermus, and Firmicutes. Actinobacteria was the most abundant phylum, followed by Proteobacteria, at both high and low temperatures. Pseudarthrobacter was the most abundant genus, accounting for 14.2% of the total isolates. Although several microorganisms grew at 10 °C, the proportion of microorganisms that grew at 25 °C was substantially higher. In particular, 50% of all bacterial isolates grew only at a high temperature (HT), whereas 21.4% of the isolates grew at a low temperature (LT), and 38.6% of the isolates grew at both HT and LT. In addition, many radiation-resistant extremophiles were identified, which adapted to both cold and oxidative conditions. The nearest neighbors of approximately >90% of bacteria belonged to a nonglacial environment, such as oil-contaminated soil, rocks, and black sand, instead of glacial niches. This study provides insights into the ecological traits, stress responses, and temporary survival of culturable heterotrophic bacteria in a newly exposed moraine with variable environmental conditions and the relationship of these communities with the non-glacial environment. This study may help to understand the evolution, competition, and selective growth of bacteria in the transition regions between glaciers and retreats in the context of glacier melting and retreat owing to global warming.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Yeteng Xu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Xiaowen Cui
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- College of Geography and Environment Science, Northwest Normal University, Lanzhou 730070, China
| | - Binglin Zhang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Xinyue Wang
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xiang Qin
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Jinxiu Wang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Yanzhao Li
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Wei Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Guangxiu Liu
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Tuo Chen
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- Correspondence: (T.C.); (G.Z.)
| | - Gaosen Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- Correspondence: (T.C.); (G.Z.)
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10
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Kohler TJ, Fodelianakis S, Michoud G, Ezzat L, Bourquin M, Peter H, Busi SB, Pramateftaki P, Deluigi N, Styllas M, Tolosano M, de Staercke V, Schön M, Brandani J, Marasco R, Daffonchio D, Wilmes P, Battin TJ. Glacier shrinkage will accelerate downstream decomposition of organic matter and alters microbiome structure and function. GLOBAL CHANGE BIOLOGY 2022; 28:3846-3859. [PMID: 35320603 PMCID: PMC9323552 DOI: 10.1111/gcb.16169] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/06/2022] [Indexed: 05/22/2023]
Abstract
The shrinking of glaciers is among the most iconic consequences of climate change. Despite this, the downstream consequences for ecosystem processes and related microbiome structure and function remain poorly understood. Here, using a space-for-time substitution approach across 101 glacier-fed streams (GFSs) from six major regions worldwide, we investigated how glacier shrinkage is likely to impact the organic matter (OM) decomposition rates of benthic biofilms. To do this, we measured the activities of five common extracellular enzymes and estimated decomposition rates by using enzyme allocation equations based on stoichiometry. We found decomposition rates to average 0.0129 (% d-1 ), and that decreases in glacier influence (estimated by percent glacier catchment coverage, turbidity, and a glacier index) accelerates decomposition rates. To explore mechanisms behind these relationships, we further compared decomposition rates with biofilm and stream water characteristics. We found that chlorophyll-a, temperature, and stream water N:P together explained 61% of the variability in decomposition. Algal biomass, which is also increasing with glacier shrinkage, showed a particularly strong relationship with decomposition, likely indicating their importance in contributing labile organic compounds to these carbon-poor habitats. We also found high relative abundances of chytrid fungi in GFS sediments, which putatively parasitize these algae, promoting decomposition through a fungal shunt. Exploring the biofilm microbiome, we then sought to identify bacterial phylogenetic clades significantly associated with decomposition, and found numerous positively (e.g., Saprospiraceae) and negatively (e.g., Nitrospira) related clades. Lastly, using metagenomics, we found evidence of different bacterial classes possessing different proportions of EEA-encoding genes, potentially informing some of the microbial associations with decomposition rates. Our results, therefore, present new mechanistic insights into OM decomposition in GFSs by demonstrating that an algal-based "green food web" is likely to increase in importance in the future and will promote important biogeochemical shifts in these streams as glaciers vanish.
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Affiliation(s)
- Tyler J. Kohler
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Stilianos Fodelianakis
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Grégoire Michoud
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Leïla Ezzat
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Massimo Bourquin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Hannes Peter
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Susheel Bhanu Busi
- Systems Ecology Research GroupLuxembourg Centre for Systems BiomedicineUniversity of LuxembourgEsch‐sur‐AlzetteLuxembourg
| | - Paraskevi Pramateftaki
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Nicola Deluigi
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Michail Styllas
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Matteo Tolosano
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Vincent de Staercke
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Martina Schön
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Jade Brandani
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Ramona Marasco
- Biological and Environmental Sciences and Engineering Division (BESE)King Abdullah University of Science and Technology (KAUST)ThuwalSaudi Arabia
| | - Daniele Daffonchio
- Biological and Environmental Sciences and Engineering Division (BESE)King Abdullah University of Science and Technology (KAUST)ThuwalSaudi Arabia
| | - Paul Wilmes
- Systems Ecology Research GroupLuxembourg Centre for Systems BiomedicineUniversity of LuxembourgEsch‐sur‐AlzetteLuxembourg
| | - Tom J. Battin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
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11
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Liu X, Shi Y, Yang T, Gao GF, Zhang L, Xu R, Li C, Liu R, Liu J, Chu H. Distinct Co-occurrence Relationships and Assembly Processes of Active Methane-Oxidizing Bacterial Communities Between Paddy and Natural Wetlands of Northeast China. Front Microbiol 2022; 13:809074. [PMID: 35154054 PMCID: PMC8826055 DOI: 10.3389/fmicb.2022.809074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/04/2022] [Indexed: 11/27/2022] Open
Abstract
Studies of methane-oxidizing bacteria are updating our views of their composition and function in paddy and natural wetlands. However, few studies have characterized differences in the methane-oxidizing bacterial communities between paddy and natural wetlands. Here, we conducted a 13C stable isotope-probing experiment and high-throughput sequencing to determine the structure profiling, co-occurrence relationships, and assembly processes of methanotrophic communities in four wetlands of Northeast China. There was a clear difference in community structure between paddy and natural wetlands. LEfSe analyses revealed that Methylobacter, FWs, and Methylosinus were enriched in natural wetlands, while Methylosarcina were prevailing in paddy, all identified as indicative methanotrophs. We observed distinct co-occurrence relationships between paddy and natural wetlands: more robust and complex connections in natural wetlands than paddy wetlands. Furthermore, the relative importance of stochastic processes was greater than that of deterministic processes, as stochastic processes explained >50% of the variation in communities. These results demonstrated that the co-occurrence relationships and assembly processes of active methanotrophic communities in paddy and natural wetlands were distinct. Overall, the results of this study enhance our understanding of the communities of methane-oxidizing bacteria in paddy and natural wetlands of Northeast China.
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Affiliation(s)
- Xu Liu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yu Shi
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Teng Yang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Gui-Feng Gao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Liyan Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, China
| | - Ruoyu Xu
- High School Affiliated to Nanjing Normal University, Nanjing, China
| | - Chenxin Li
- High School Affiliated to Nanjing Normal University, Nanjing, China
| | - Ruiyang Liu
- High School Affiliated to Nanjing Normal University, Nanjing, China
| | - Junjie Liu
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Haiyan Chu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.,University of Chinese Academy of Sciences, Beijing, China
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12
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Varliero G, Anesio AM, Barker GLA. A Taxon-Wise Insight Into Rock Weathering and Nitrogen Fixation Functional Profiles of Proglacial Systems. Front Microbiol 2021; 12:627437. [PMID: 34621246 PMCID: PMC8491546 DOI: 10.3389/fmicb.2021.627437] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 08/05/2021] [Indexed: 11/13/2022] Open
Abstract
The Arctic environment is particularly affected by global warming, and a clear trend of the ice retreat is observed worldwide. In proglacial systems, the newly exposed terrain represents different environmental and nutrient conditions compared to later soil stages. Therefore, proglacial systems show several environmental gradients along the soil succession where microorganisms are active protagonists of the soil and carbon pool formation through nitrogen fixation and rock weathering. We studied the microbial succession of three Arctic proglacial systems located in Svalbard (Midtre Lovénbreen), Sweden (Storglaciären), and Greenland (foreland close to Kangerlussuaq). We analyzed 65 whole shotgun metagenomic soil samples for a total of more than 400 Gb of sequencing data. Microbial succession showed common trends typical of proglacial systems with increasing diversity observed along the forefield chronosequence. Microbial trends were explained by the distance from the ice edge in the Midtre Lovénbreen and Storglaciären forefields and by total nitrogen (TN) and total organic carbon (TOC) in the Greenland proglacial system. Furthermore, we focused specifically on genes associated with nitrogen fixation and biotic rock weathering processes, such as nitrogenase genes, obcA genes, and genes involved in cyanide and siderophore synthesis and transport. Whereas we confirmed the presence of these genes in known nitrogen-fixing and/or rock weathering organisms (e.g., Nostoc, Burkholderia), in this study, we also detected organisms that, even if often found in soil and proglacial systems, have never been related to nitrogen-fixing or rock weathering processes before (e.g., Fimbriiglobus, Streptomyces). The different genera showed different gene trends within and among the studied systems, indicating a community constituted by a plurality of organisms involved in nitrogen fixation and biotic rock weathering, and where the latter were driven by different organisms at different soil succession stages.
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Affiliation(s)
- Gilda Varliero
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | | | - Gary L. A. Barker
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
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13
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Fodelianakis S, Washburne AD, Bourquin M, Pramateftaki P, Kohler TJ, Styllas M, Tolosano M, De Staercke V, Schön M, Busi SB, Brandani J, Wilmes P, Peter H, Battin TJ. Microdiversity characterizes prevalent phylogenetic clades in the glacier-fed stream microbiome. ISME JOURNAL 2021; 16:666-675. [PMID: 34522009 PMCID: PMC8857233 DOI: 10.1038/s41396-021-01106-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 08/14/2021] [Accepted: 09/02/2021] [Indexed: 02/01/2023]
Abstract
Glacier-fed streams (GFSs) are extreme and rapidly vanishing ecosystems, and yet they harbor diverse microbial communities. Although our understanding of the GFS microbiome has recently increased, we do not know which microbial clades are ecologically successful in these ecosystems, nor do we understand potentially underlying mechanisms. Ecologically successful clades should be more prevalent across GFSs compared to other clades, which should be reflected as clade-wise distinctly low phylogenetic turnover. However, methods to assess such patterns are currently missing. Here we developed and applied a novel analytical framework, “phyloscore analysis”, to identify clades with lower spatial phylogenetic turnover than other clades in the sediment microbiome across twenty GFSs in New Zealand. These clades constituted up to 44% and 64% of community α-diversity and abundance, respectively. Furthermore, both their α-diversity and abundance increased as sediment chlorophyll a decreased, corroborating their ecological success in GFS habitats largely devoid of primary production. These clades also contained elevated levels of putative microdiversity than others, which could potentially explain their high prevalence in GFSs. This hitherto unknown microdiversity may be threatened as glaciers shrink, urging towards further genomic and functional exploration of the GFS microbiome.
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Affiliation(s)
- Stilianos Fodelianakis
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland.
| | | | - Massimo Bourquin
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Paraskevi Pramateftaki
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Tyler J Kohler
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Michail Styllas
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Matteo Tolosano
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Vincent De Staercke
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Martina Schön
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Susheel Bhanu Busi
- Systems Ecology Research Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Jade Brandani
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Paul Wilmes
- Systems Ecology Research Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Hannes Peter
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Tom J Battin
- Stream Biofilm & Ecosystem Research Lab, ENAC Division, Ecole Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland.
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14
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15
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Irvine-Fynn TDL, Edwards A, Stevens IT, Mitchell AC, Bunting P, Box JE, Cameron KA, Cook JM, Naegeli K, Rassner SME, Ryan JC, Stibal M, Williamson CJ, Hubbard A. Storage and export of microbial biomass across the western Greenland Ice Sheet. Nat Commun 2021; 12:3960. [PMID: 34172727 PMCID: PMC8233322 DOI: 10.1038/s41467-021-24040-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 05/21/2021] [Indexed: 11/23/2022] Open
Abstract
The Greenland Ice Sheet harbours a wealth of microbial life, yet the total biomass stored or exported from its surface to downstream environments is unconstrained. Here, we quantify microbial abundance and cellular biomass flux within the near-surface weathering crust photic zone of the western sector of the ice sheet. Using groundwater techniques, we demonstrate that interstitial water flow is slow (~10−2 m d−1), while flow cytometry enumeration reveals this pathway delivers 5 × 108 cells m−2 d−1 to supraglacial streams, equivalent to a carbon flux up to 250 g km−2 d−1. We infer that cellular carbon accumulation in the weathering crust exceeds fluvial export, promoting biomass sequestration, enhanced carbon cycling, and biological albedo reduction. We estimate that up to 37 kg km−2 of cellular carbon is flushed from the weathering crust environment of the western Greenland Ice Sheet each summer, providing an appreciable flux to support heterotrophs and methanogenesis at the bed. Microbes that colonise ice sheet surfaces are important to the carbon cycle, but their biomass and transport remains unquantified. Here, the authors reveal substantial microbial carbon fluxes across Greenland’s ice surface, in quantities that may sustain subglacial heterotrophs and fuel methanogenesis.
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Affiliation(s)
- T D L Irvine-Fynn
- Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK.
| | - A Edwards
- Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
| | - I T Stevens
- Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK.,School of Geography, Politics and Sociology, Newcastle University, Newcastle-upon-Tyne, UK.,Department of Environmental Science, Aarhus University, Frederiksborgvej, Roskilde, Denmark
| | - A C Mitchell
- Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK
| | - P Bunting
- Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK
| | - J E Box
- Department of Glaciology and Climate, Geological Survey of Denmark and Greenland, Copenhagen, Denmark
| | - K A Cameron
- Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK.,Department of Glaciology and Climate, Geological Survey of Denmark and Greenland, Copenhagen, Denmark.,School of Geographical and Earth Sciences, University of Glasgow, Glasgow, UK
| | - J M Cook
- Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK.,Department of Environmental Science, Aarhus University, Frederiksborgvej, Roskilde, Denmark.,Department of Geography, University of Sheffield, Sheffield, UK
| | - K Naegeli
- Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK.,Institute of Geography and Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
| | - S M E Rassner
- Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
| | - J C Ryan
- Institute at Brown for Environment and Society, Brown University, Providence, RI, USA
| | - M Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - C J Williamson
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, UK
| | - A Hubbard
- Centre for Gas Hydrate, Environment and Climate, Department of Geosciences, UiT-The Arctic University of Norway, Tromsø, Norway.,Geography Research Unit, University of Oulu, Oulu, Finland
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16
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Tendulkar S, Hattiholi A, Chavadar M, Dodamani S. Psychrophiles: A journey of hope. J Biosci 2021; 46:64. [PMID: 34219740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Psychrophiles are organisms living in extremely cold conditions within the temperature range of -20°C to +10°C. These organisms survive in harsh environment by modulating their genetic make-up to thrive in extremely cold conditions. These cold-adaptations are closely associated with changes in the life forms, gene expression, and proteins, enzymes, lipids, etc. This review gives a brief description of the life and genetic adaptations of psychrophiles for their survival in extreme conditions as well as the bioactive compounds that are potential antimicrobials.
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Affiliation(s)
- Shivani Tendulkar
- Dr. Prabhakar Kore Basic Science Research Center, KLE Academy of Higher Education and Research, Belagavi 590 010, India
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17
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Bacterial and archaeal community structure in benthic sediments from glacial lakes at the Múlajökull Glacier, central Iceland. Polar Biol 2020. [DOI: 10.1007/s00300-020-02770-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Sułowicz S, Bondarczuk K, Ignatiuk D, Jania JA, Piotrowska-Seget Z. Microbial communities from subglacial water of naled ice bodies in the forefield of Werenskioldbreen, Svalbard. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 723:138025. [PMID: 32213417 DOI: 10.1016/j.scitotenv.2020.138025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 03/16/2020] [Accepted: 03/16/2020] [Indexed: 06/10/2023]
Abstract
We assessed the structure of microbial communities in the subglacial drainage system of the Werenskioldbreen glacier, Svalbard, which consists of three independent channels. Dome-shaped naled ice bodies that had been forming and releasing subglacial water in the glacial forefield during accumulations season were used to study glacial microbiome. We tested the hypothesis that the properties of the water transported by these channels are site-dependent and influence bacterial diversity. We therefore established the phylogenetic structure of the subglacial microbial communities using next generation sequencing (NGS) of the 16S rRNA gene and performed bioinformatics analyses. A total of 1409 OTUs (operational taxonomic units) belonged to 40 phyla; mostly Proteobacteria, Gracilibacteria, Bacteroidetes, Actinobacteria and Parcubacteria were identified. Sites located on the edge of Werenskioldbreen forefield (Angell, Kvisla) were mainly dominated by Betaproteobacteria. In the central site (Dusan) domination of Epsilonproteobacteria class was observed. Gracilibacteria (GN02) and Gammaproteobacteria represented the dominant taxa only in the sample Kvisla 2. Principal Coordinate Analysis (PCoA) of beta diversity revealed that phylogenetic profiles grouped in three different clusters according to the sampling site. Moreover, higher similarity of bacterial communities from Angell and Kvisla compared to Dusan was confirmed by cluster analysis and Venn diagrams. The highest alpha index values was measured in Dusan. Richness and phylogenetic diversity indices were significantly (p < .05) and positively correlated with pH values of subglacial water and negatively with concentration of Cl-, Br-, and NO3- anions. These anions negatively impacted the values of richness indices but positively correlated with abundance of some microbial phyla. Our results indicated that subglacial water from naled ice bodies offer the possibility to study the glacial microbiome. In the studied subglacial water, the microbial community structure was sampling site specific and dependent on the water properties, which in turn were probably influenced by the local bedrock composition.
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Affiliation(s)
- Sławomir Sułowicz
- University of Silesia in Katowice, Faculty of Natural Sciences, Institute of Biology, Biotechnology and Environmental Protection, Jagiellonska 28, 40-032 Katowice, Poland.
| | - Kinga Bondarczuk
- Medical University of Bialystok, Centre for Bioinformatics and Data Analysis, Waszyngtona 13a, 15-269 Bialystok, Poland
| | - Dariusz Ignatiuk
- University of Silesia in Katowice, Faculty of Natural Sciences, Institute of Earth Sciences, Bedzinska 60, 41-205 Sosnowiec, Poland; Svalbard Integrated Arctic Earth Observing System (SIOS), SIOS Knowledge Centre, Svalbard Science Centre, P.O. Box 156, N-9171 Longyearbyen, Svalbard, Norway
| | - Jacek A Jania
- University of Silesia in Katowice, Faculty of Natural Sciences, Institute of Earth Sciences, Bedzinska 60, 41-205 Sosnowiec, Poland
| | - Zofia Piotrowska-Seget
- University of Silesia in Katowice, Faculty of Natural Sciences, Institute of Biology, Biotechnology and Environmental Protection, Jagiellonska 28, 40-032 Katowice, Poland
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19
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Cameron KA, Müller O, Stibal M, Edwards A, Jacobsen CS. Glacial microbiota are hydrologically connected and temporally variable. Environ Microbiol 2020; 22:3172-3187. [PMID: 32383292 DOI: 10.1111/1462-2920.15059] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/15/2020] [Accepted: 05/02/2020] [Indexed: 11/29/2022]
Abstract
Glaciers are melting rapidly. The concurrent export of microbial assemblages alongside glacial meltwater is expected to impact the ecology of adjoining ecosystems. Currently, the source of exported assemblages is poorly understood, yet this information may be critical for understanding how current and future glacial melt seasons may influence downstream environments. We report on the connectivity and temporal variability of microbiota sampled from supraglacial, subglacial and periglacial habitats and water bodies within a glacial catchment. Sampled assemblages showed evidence of being biologically connected through hydrological flowpaths, leading to a meltwater system that accumulates prokaryotic biota as it travels downstream. Temporal changes in the connected assemblages were similarly observed. Snow assemblages changed markedly throughout the sample period, likely reflecting changes in the surrounding environment. Changes in supraglacial meltwater assemblages reflected the transition of the glacial surface from snow-covered to bare-ice. Marked snowmelt across the surrounding periglacial environment resulted in the flushing of soil assemblages into the riverine system. In contrast, surface ice within the ablation zone and subglacial meltwaters remained relatively stable throughout the sample period. Our results are indicative that changes in snow and ice melt across glacial environments will influence the abundance and diversity of microbial assemblages transported downstream.
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Affiliation(s)
- Karen A Cameron
- Institute of Biological, Rural and Environmental Sciences (IBERS), Aberystwyth University, Aberystwyth, SY23 3DD, UK.,Center for Permafrost (CENPERM), University of Copenhagen, Copenhagen, 1350, Denmark.,Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, 1350, Denmark.,School of Geographical and Earth Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Oliver Müller
- Department of Biological Sciences, University of Bergen, Bergen, 5006, Norway
| | - Marek Stibal
- Center for Permafrost (CENPERM), University of Copenhagen, Copenhagen, 1350, Denmark.,Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, 1350, Denmark.,Department of Ecology, Faculty of Science, Charles University, Prague, 128 44, Czech Republic
| | - Arwyn Edwards
- Institute of Biological, Rural and Environmental Sciences (IBERS), Aberystwyth University, Aberystwyth, SY23 3DD, UK
| | - Carsten Suhr Jacobsen
- Center for Permafrost (CENPERM), University of Copenhagen, Copenhagen, 1350, Denmark.,Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, 1350, Denmark.,Department of Environmental Science, Aarhus University, Roskilde, 4000, Denmark
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20
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Giongo A, Granada CE, Borges LGA, Pereira LM, Trindade FJ, Mattiello SP, Oliveira RR, Shubeita FM, Lovato A, Marcon C, Medina-Silva R. Microbial communities in anaerobic digesters change over time and sampling depth. Braz J Microbiol 2020; 51:1177-1190. [PMID: 32394239 DOI: 10.1007/s42770-020-00272-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 04/09/2020] [Indexed: 10/24/2022] Open
Abstract
Anaerobic digestion (AD) is a process resulting from the anaerobic metabolism of specific microorganisms that produce an eco-friendly type of energy and a stabilized soil fertilizer. We described the microbial communities and their changes in three depths of BioKöhler® biodigester, fed with cattle manure for 18 days, under anaerobic incubation at the psychrophilic temperature range (~ 20 °C). During the experiment, the maximum methane content in the raw biogas was 79.9%. Non-metric multidimensional scaling (MDS) showed significant differences among microbial communities in the bottom, medium, and upper depths. Considering all the periods of incubation, the microbial communities changed until the eighth day, and they remained stable from eighth to seventeenth days. Bacteroidetes, Firmicutes, and Synergistetes were the most abundant phyla in samples, representing approximately 41% of the total OTUs. The relative abundance of the phyla Euryarchaeota, Actinobacteria, Firmicutes, and Verrucomicrobia changed from bottom to medium sampling points. Moreover, Crenarchaeota differed in frequencies from medium to upper, and Acidobacteria from bottom to upper samples. Lentisphaerae, Chloroflexi, and LD1 were different solely at the bottom, whereas OP9 and Tenericutes only in the medium. Psychrophilic AD performed in this work removed pathogens like Salmonella and Escherichia, as observed at the digestate analyzed. This type of treatment of raw manure besides producing eco-friendly energy efficiently also generates a stabilized and safe biomass that can be used as fertilizer in soils.
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Affiliation(s)
- Adriana Giongo
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Instituto do Petróleo e dos Recursos Naturais, Porto Alegre, RS, Brazil
| | - Camille E Granada
- Programa de Pós-graduação em Biotecnologia, Universidade do Vale do Taquari (UNIVATES), Rua Avelino Tallini, 171, Lajeado, RS, Brazil.
| | - Luiz G A Borges
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Instituto do Petróleo e dos Recursos Naturais, Porto Alegre, RS, Brazil
| | - Leandro M Pereira
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Escola de Ciências da Saúde da Vida, Porto Alegre, RS, Brazil
| | - Fernanda J Trindade
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Escola de Ciências da Saúde da Vida, Porto Alegre, RS, Brazil
| | - Shaiana P Mattiello
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Instituto do Petróleo e dos Recursos Naturais, Porto Alegre, RS, Brazil.,Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Escola de Ciências da Saúde da Vida, Porto Alegre, RS, Brazil
| | - Rafael R Oliveira
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Instituto do Petróleo e dos Recursos Naturais, Porto Alegre, RS, Brazil
| | - Fauzi M Shubeita
- Sociedade Educacional Três de Maio (SETREM), Três de Maio, RS, Brazil.,Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Escola Politécnica, Porto Alegre, RS, Brazil
| | | | - César Marcon
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Escola Politécnica, Porto Alegre, RS, Brazil
| | - Renata Medina-Silva
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Instituto do Petróleo e dos Recursos Naturais, Porto Alegre, RS, Brazil.,Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Escola de Ciências da Saúde da Vida, Porto Alegre, RS, Brazil
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21
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Edwards A, Cameron KA, Cook JM, Debbonaire AR, Furness E, Hay MC, Rassner SM. Microbial genomics amidst the Arctic crisis. Microb Genom 2020; 6:e000375. [PMID: 32392124 PMCID: PMC7371112 DOI: 10.1099/mgen.0.000375] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/16/2020] [Indexed: 12/16/2022] Open
Abstract
The Arctic is warming - fast. Microbes in the Arctic play pivotal roles in feedbacks that magnify the impacts of Arctic change. Understanding the genome evolution, diversity and dynamics of Arctic microbes can provide insights relevant for both fundamental microbiology and interdisciplinary Arctic science. Within this synthesis, we highlight four key areas where genomic insights to the microbial dimensions of Arctic change are urgently required: the changing Arctic Ocean, greenhouse gas release from the thawing permafrost, 'biological darkening' of glacial surfaces, and human activities within the Arctic. Furthermore, we identify four principal challenges that provide opportunities for timely innovation in Arctic microbial genomics. These range from insufficient genomic data to develop unifying concepts or model organisms for Arctic microbiology to challenges in gaining authentic insights to the structure and function of low-biomass microbiota and integration of data on the causes and consequences of microbial feedbacks across scales. We contend that our insights to date on the genomics of Arctic microbes are limited in these key areas, and we identify priorities and new ways of working to help ensure microbial genomics is in the vanguard of the scientific response to the Arctic crisis.
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Affiliation(s)
- Arwyn Edwards
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Karen A. Cameron
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Joseph M. Cook
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Aliyah R. Debbonaire
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Eleanor Furness
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Melanie C. Hay
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Sara M.E. Rassner
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
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22
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Kohler TJ, Vinšová P, Falteisek L, Žárský JD, Yde JC, Hatton JE, Hawkings JR, Lamarche-Gagnon G, Hood E, Cameron KA, Stibal M. Patterns in Microbial Assemblages Exported From the Meltwater of Arctic and Sub-Arctic Glaciers. Front Microbiol 2020; 11:669. [PMID: 32351489 PMCID: PMC7174618 DOI: 10.3389/fmicb.2020.00669] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/24/2020] [Indexed: 01/14/2023] Open
Abstract
Meltwater streams connect the glacial cryosphere with downstream ecosystems. Dissolved and particulate matter exported from glacial ecosystems originates from contrasting supraglacial and subglacial environments, and exported microbial cells have the potential to serve as ecological and hydrological indicators for glacial ecosystem processes. Here, we compare exported microbial assemblages from the meltwater of 24 glaciers from six (sub)Arctic regions – the southwestern Greenland Ice Sheet, Qeqertarsuaq (Disko Island) in west Greenland, Iceland, Svalbard, western Norway, and southeast Alaska – differing in their lithology, catchment size, and climatic characteristics, to investigate spatial and environmental factors structuring exported meltwater assemblages. We found that 16S rRNA gene sequences of all samples were dominated by the phyla Proteobacteria, Bacteroidetes, and Actinobacteria, with Verrucomicrobia also common in Greenland localities. Clustered OTUs were largely composed of aerobic and anaerobic heterotrophs capable of degrading a wide variety of carbon substrates. A small number of OTUs dominated all assemblages, with the most abundant being from the genera Polaromonas, Methylophilus, and Nitrotoga. However, 16–32% of a region’s OTUs were unique to that region, and rare taxa revealed unique metabolic potentials and reflected differences between regions, such as the elevated relative abundances of sulfur oxidizers Sulfuricurvum sp. and Thiobacillus sp. at Svalbard sites. Meltwater alpha diversity showed a pronounced decrease with increasing latitude, and multivariate analyses of assemblages revealed significant regional clusters. Distance-based redundancy and correlation analyses further resolved associations between whole assemblages and individual OTUs with variables primarily corresponding with the sampled regions. Interestingly, some OTUs indicating specific metabolic processes were not strongly associated with corresponding meltwater characteristics (e.g., nitrification and inorganic nitrogen concentrations). Thus, while exported assemblage structure appears regionally specific, and probably reflects differences in dominant hydrological flowpaths, OTUs can also serve as indicators for more localized microbially mediated processes not captured by the traditional characterization of bulk meltwater hydrochemistry. These results collectively promote a better understanding of microbial distributions across the Arctic, as well as linkages between the terrestrial cryosphere habitats and downstream ecosystems.
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Affiliation(s)
- Tyler J Kohler
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia.,Stream Biofilm and Ecosystem Research Laboratory, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Petra Vinšová
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Lukáš Falteisek
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Jakub D Žárský
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Jacob C Yde
- Department of Environmental Sciences, Western Norway University of Applied Sciences, Sogndal, Norway
| | - Jade E Hatton
- School of Earth Sciences, University of Bristol, Bristol, United Kingdom
| | - Jon R Hawkings
- National High Magnetic Field Laboratory, Department of Earth, Ocean & Atmospheric Science, Florida State University, Tallahassee, FL, United States.,GFZ German Research Centre for Geosciences, Potsdam, Germany
| | | | - Eran Hood
- Department of Natural Sciences, University of Alaska Southeast, Juneau, AK, United States
| | - Karen A Cameron
- Institute of Biological, Environmental and Rural Sciences, Faculty of Earth and Life Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
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23
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Wadham JL, Hawkings JR, Tarasov L, Gregoire LJ, Spencer RGM, Gutjahr M, Ridgwell A, Kohfeld KE. Ice sheets matter for the global carbon cycle. Nat Commun 2019; 10:3567. [PMID: 31417076 PMCID: PMC6695407 DOI: 10.1038/s41467-019-11394-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 07/09/2019] [Indexed: 11/09/2022] Open
Abstract
The cycling of carbon on Earth exerts a fundamental influence upon the greenhouse gas content of the atmosphere, and hence global climate over millennia. Until recently, ice sheets were viewed as inert components of this cycle and largely disregarded in global models. Research in the past decade has transformed this view, demonstrating the existence of uniquely adapted microbial communities, high rates of biogeochemical/physical weathering in ice sheets and storage and cycling of organic carbon (>104 Pg C) and nutrients. Here we assess the active role of ice sheets in the global carbon cycle and potential ramifications of enhanced melt and ice discharge in a warming world.
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Affiliation(s)
- J L Wadham
- University of Bristol, Bristol, BS8 1TH, UK.
| | - J R Hawkings
- National High Magnetic Field Lab and Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, 32306, USA
- German Research Centre for Geosciences GFZ, 14473, Potsdam, Germany
| | - L Tarasov
- Memorial University, St. John's, NF, A1B 3X9, Canada
| | | | - R G M Spencer
- National High Magnetic Field Lab and Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, 32306, USA
| | | | - A Ridgwell
- University of California, Riverside, CA, 94720, USA
| | - K E Kohfeld
- Simon Fraser University, Burnaby, BC, 8888, Canada
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24
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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: 71] [Impact Index Per Article: 14.2] [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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25
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26
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Lamarche-Gagnon G, Wadham JL, Sherwood Lollar B, Arndt S, Fietzek P, Beaton AD, Tedstone AJ, Telling J, Bagshaw EA, Hawkings JR, Kohler TJ, Zarsky JD, Mowlem MC, Anesio AM, Stibal M. Greenland melt drives continuous export of methane from the ice-sheet bed. Nature 2019; 565:73-77. [PMID: 30602750 DOI: 10.1038/s41586-018-0800-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 11/08/2018] [Indexed: 12/24/2022]
Abstract
Ice sheets are currently ignored in global methane budgets1,2. Although ice sheets have been proposed to contain large reserves of methane that may contribute to a rise in atmospheric methane concentration if released during periods of rapid ice retreat3,4, no data exist on the current methane footprint of ice sheets. Here we find that subglacially produced methane is rapidly driven to the ice margin by the efficient drainage system of a subglacial catchment of the Greenland ice sheet. We report the continuous export of methane-supersaturated waters (CH4(aq)) from the ice-sheet bed during the melt season. Pulses of high CH4(aq) concentration coincide with supraglacially forced subglacial flushing events, confirming a subglacial source and highlighting the influence of melt on methane export. Sustained methane fluxes over the melt season are indicative of subglacial methane reserves that exceed methane export, with an estimated 6.3 tonnes (discharge-weighted mean; range from 2.4 to 11 tonnes) of CH4(aq) transported laterally from the ice-sheet bed. Stable-isotope analyses reveal a microbial origin for methane, probably from a mixture of inorganic and ancient organic carbon buried beneath the ice. We show that subglacial hydrology is crucial for controlling methane fluxes from the ice sheet, with efficient drainage limiting the extent of methane oxidation5 to about 17 per cent of methane exported. Atmospheric evasion is the main methane sink once runoff reaches the ice margin, with estimated diffusive fluxes (4.4 to 28 millimoles of CH4 per square metre per day) rivalling that of major world rivers6. Overall, our results indicate that ice sheets overlie extensive, biologically active methanogenic wetlands and that high rates of methane export to the atmosphere can occur via efficient subglacial drainage pathways. Our findings suggest that such environments have been previously underappreciated and should be considered in Earth's methane budget.
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Affiliation(s)
| | - Jemma L Wadham
- School of Geographical Sciences, University of Bristol, Bristol, UK
| | | | - Sandra Arndt
- Department of Geoscience, Environment and Society, Université Libre de Bruxelles, Brussels, Belgium
| | | | | | | | - Jon Telling
- School of Natural and Environmental Sciences, Newcastle University, Newcastle, UK
| | | | - Jon R Hawkings
- School of Geographical Sciences, University of Bristol, Bristol, UK.,National High Magnetic Field Lab and Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA.,German Research Centre for Geosciences GFZ, Potsdam, Germany
| | - Tyler J Kohler
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Jakub D Zarsky
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | | | - Alexandre M Anesio
- Department of Environmental Sciences, Aarhus University, Roskilde, Denmark
| | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
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27
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Direct isotopic evidence of biogenic methane production and efflux from beneath a temperate glacier. Sci Rep 2018; 8:17118. [PMID: 30459433 PMCID: PMC6244297 DOI: 10.1038/s41598-018-35253-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 10/18/2018] [Indexed: 11/08/2022] Open
Abstract
The base of glaciers and ice sheets provide environments suitable for the production of methane. High pressure conditions beneath the impermeable 'cap' of overlying ice promote entrapment of methane reserves that can be released to the atmosphere during ice thinning and meltwater evacuation. However, contemporary glaciers and ice sheets are rarely accounted for as methane contributors through field measurements. Here, we present direct field-based evidence of methane production and release from beneath the Icelandic glacier Sólheimajökull, where geothermal activity creates sub-oxic conditions suited to methane production and preservation along the meltwater flow path. Methane production at the glacier bed (48 tonnes per day, or 39 mM CH4 m-2 day-1), and evasion to the atmosphere from the proglacial stream (41 tonnes per day, or 32 M CH4 m-2 day-1) indicates considerable production and release to the atmosphere during the summer melt season. Isotopic signatures (-60.2‰ to -7.6‰ for δ13CCH4 and -324.3‰ to +161.1‰ for DCH4), support a biogenic signature within waters emerging from the subglacial environment. Temperate glacial methane production and release may thus be a significant and hitherto unresolved contributor of a potent greenhouse gas to the atmosphere.
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28
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First observation of direct methane emission to the atmosphere from the subglacial domain of the Greenland Ice Sheet. Sci Rep 2018; 8:16623. [PMID: 30413774 PMCID: PMC6226494 DOI: 10.1038/s41598-018-35054-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 10/30/2018] [Indexed: 11/08/2022] Open
Abstract
During a 2016 field expedition to the West Greenland Ice Sheet, a striking observation of significantly elevated CH4 concentrations of up to 15 times the background atmospheric concentration were measured directly in the air expelled with meltwater at a subglacial discharge point from the Greenland Ice Sheet. The range of hourly subglacial CH4 flux rate through the discharge point was estimated to be 3.1 to 134 g CH4 hr-1. These measurements are the first observations of direct emissions of CH4 from the subglacial environment under the Greenlandic Ice Sheet to the atmosphere and indicate a novel emission pathway of CH4 that is currently a non-quantified component of the Arctic CH4 budget.
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29
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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: 12] [Impact Index Per Article: 2.0] [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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30
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Žárský JD, Kohler TJ, Yde JC, Falteisek L, Lamarche-Gagnon G, Hawkings JR, Hatton JE, Stibal M. Prokaryotic assemblages in suspended and subglacial sediments within a glacierized catchment on Qeqertarsuaq (Disko Island), west Greenland. FEMS Microbiol Ecol 2018; 94:5017442. [DOI: 10.1093/femsec/fiy100] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 05/27/2018] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jakub D Žárský
- Department of Ecology, Faculty of Science, Charles University, Prague, Vinicna 7, 128 44 Prague 2, Czechia
| | - Tyler J Kohler
- Department of Ecology, Faculty of Science, Charles University, Prague, Vinicna 7, 128 44 Prague 2, Czechia
| | - Jacob C Yde
- Department of Environment Sciences, Western Norway University of Applied Sciences, Royrgata 6, 6856 Sogndal, Norway
| | - Lukáš Falteisek
- Department of Ecology, Faculty of Science, Charles University, Prague, Vinicna 7, 128 44 Prague 2, Czechia
| | - Guillaume Lamarche-Gagnon
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - Jon R Hawkings
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - Jade E Hatton
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Vinicna 7, 128 44 Prague 2, Czechia
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31
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Draft Genome Sequence of Methylovulum psychrotolerans Sph1 T, an Obligate Methanotroph from Low-Temperature Environments. GENOME ANNOUNCEMENTS 2018; 6:6/11/e01488-17. [PMID: 29545306 PMCID: PMC5854766 DOI: 10.1128/genomea.01488-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Methylovulum psychrotolerans Sph1T is an aerobic, obligate methanotroph, which was isolated from cold methane seeps in West Siberia. This bacterium possesses only a particulate methane monooxygenase and is widely distributed in low-temperature environments. Strain Sph1T has the genomic potential for biosynthesis of hopanoids required for the maintenance of intracytoplasmic membranes.
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32
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Ma H, Yan W, Xiao X, Shi G, Li Y, Sun B, Dou Y, Zhang Y. Ex Situ Culturing Experiments Revealed Psychrophilic Hydrogentrophic Methanogenesis Being the Potential Dominant Methane-Producing Pathway in Subglacial Sediment in Larsemann Hills, Antarctic. Front Microbiol 2018. [PMID: 29515536 PMCID: PMC5826372 DOI: 10.3389/fmicb.2018.00237] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
It was recognized only recently that subglacial ecosystems support considerable methanogenic activity, thus significantly contributing the global methane production. However, only limited knowledge is available on the physiological characteristics of this kind of methanogenic community because of the technical constraints associated with sampling and cultivation under corresponding environmental conditions. To elucidate methanogenesis beneath the glacial margin in East Antarctic Ice Sheet, we took an integrated approach that included cultivation of microbes associated with the sediment samples in the lab and analysis of mcrA gene therein. After 7 months of incubation, the highest rate of methanogenesis [398 (pmol/day)/gram] was observed at 1°C on a supply of H2. The rates of methanogenesis were lower on acetate or unamended substrate than on H2. The rates on these two substrates increased when the temperature was raised. Methanomicrobiales predominated before and after prolonged incubation, regardless whether H2, acetate, or unamended substrate were the energy source. Therefore, it was inferred that psychrophilic hydrogenotrophic methanogenesis was the primary methane-producing pathway in the subglacial ecosystem we sampled. These findings highlight the effects of temperature and substrate on potential methanogenesis in the subglacial sediment of this area, and may help us for a better estimation on the Antarctica methane production in a changing climate.
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Affiliation(s)
- Hongmei Ma
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, China
| | - Wenkai Yan
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiang Xiao
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Guitao Shi
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, China
| | - Yuansheng Li
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, China
| | - Bo Sun
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, China
| | - Yinke Dou
- College of Electrical and Power Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Yu Zhang
- State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, China.,Institute of Oceanography, Shanghai Jiao Tong University, Shanghai, China
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Hosen JD, Febria CM, Crump BC, Palmer MA. Watershed Urbanization Linked to Differences in Stream Bacterial Community Composition. Front Microbiol 2017; 8:1452. [PMID: 28824582 PMCID: PMC5539594 DOI: 10.3389/fmicb.2017.01452] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/18/2017] [Indexed: 11/13/2022] Open
Abstract
Urbanization strongly influences headwater stream chemistry and hydrology, but little is known about how these conditions impact bacterial community composition. We predicted that urbanization would impact bacterial community composition, but that stream water column bacterial communities would be most strongly linked to urbanization at a watershed-scale, as measured by impervious cover, while sediment bacterial communities would correlate with environmental conditions at the scale of stream reaches. To test this hypothesis, we determined bacterial community composition in the water column and sediment of headwater streams located across a gradient of watershed impervious cover using high-throughput 16S rRNA gene amplicon sequencing. Alpha diversity metrics did not show a strong response to catchment urbanization, but beta diversity was significantly related to watershed impervious cover with significant differences also found between water column and sediment samples. Samples grouped primarily according to habitat—water column vs. sediment—with a significant response to watershed impervious cover nested within each habitat type. Compositional shifts for communities in urbanized streams indicated an increase in taxa associated with human activity including bacteria from the genus Polynucleobacter, which is widespread, but has been associated with eutrophic conditions in larger water bodies. Another indicator of communities in urbanized streams was an OTU from the genus Gallionella, which is linked to corrosion of water distribution systems. To identify changes in bacterial community interactions, bacterial co-occurrence networks were generated from urban and forested samples. The urbanized co-occurrence network was much smaller and had fewer co-occurrence events per taxon than forested equivalents, indicating a loss of keystone taxa with urbanization. Our results suggest that urbanization has significant impacts on the community composition of headwater streams, and suggest that processes driving these changes in urbanized water column vs. sediment environments are distinct.
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Affiliation(s)
- Jacob D Hosen
- Chesapeake Biological LaboratorySolomons, MD, United States.,Department of Entomology, University of MarylandCollege Park, MD, United States.,College of Earth, Ocean, and Atmospheric Sciences, Oregon State UniversityCorvallis, OR, United States
| | - Catherine M Febria
- Chesapeake Biological LaboratorySolomons, MD, United States.,School of Biological Sciences, University of CanterburyChristchurch, New Zealand
| | - Byron C Crump
- School of Forestry and Environmental Studies, Yale UniversityNew Haven, CT, United States
| | - Margaret A Palmer
- Chesapeake Biological LaboratorySolomons, MD, United States.,Department of Entomology, University of MarylandCollege Park, MD, United States.,National Socio-Environmental Synthesis CenterAnnapolis, MD, United States
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Cameron KA, Stibal M, Olsen NS, Mikkelsen AB, Elberling B, Jacobsen CS. Potential Activity of Subglacial Microbiota Transported to Anoxic River Delta Sediments. MICROBIAL ECOLOGY 2017; 74:6-9. [PMID: 28070677 PMCID: PMC5486838 DOI: 10.1007/s00248-016-0926-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/26/2016] [Indexed: 06/06/2023]
Abstract
The Watson River drains a portion of the SW Greenland ice sheet, transporting microbial communities from subglacial environments to a delta at the head of Søndre Strømfjord. This study investigates the potential activity and community shifts of glacial microbiota deposited and buried under layers of sediments within the river delta. A long-term (12-month) incubation experiment was established using Watson River delta sediment under anaerobic conditions, with and without CO2/H2 enrichment. Within CO2/H2-amended incubations, sulphate depletion and a shift in the microbial community to a 52% predominance of Desulfosporosinus meridiei by day 371 provides evidence for sulphate reduction. We found evidence of methanogenesis in CO2/H2-amended incubations within the first 5 months, with production rates of ~4 pmol g-1 d-1, which was likely performed by methanogenic Methanomicrobiales- and Methanosarcinales-related organisms. Later, a reduction in methane was observed to be paired with the depletion of sulphate, and we hypothesise that sulphate reduction out competed hydrogenotrophic methanogenesis. The structure and diversity of the original CO2/H2-amended incubation communities changed dramatically with a major shift in predominant community members and a decline in diversity and cell abundance. These results highlight the need for further investigations into the fate of subglacial microbiota within downstream environments.
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Affiliation(s)
- Karen A Cameron
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350, Copenhagen, Denmark.
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark.
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Penglais, Aberystwyth, SY23 3FL, UK.
| | - Marek Stibal
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350, Copenhagen, Denmark
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 128 43, Prague, Czech Republic
| | - Nikoline S Olsen
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350, Copenhagen, Denmark
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Andreas B Mikkelsen
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Bo Elberling
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Carsten S Jacobsen
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350, Copenhagen, Denmark
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark
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35
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Hotaling S, Hood E, Hamilton TL. Microbial ecology of mountain glacier ecosystems: biodiversity, ecological connections and implications of a warming climate. Environ Microbiol 2017; 19:2935-2948. [PMID: 28419666 DOI: 10.1111/1462-2920.13766] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/08/2017] [Accepted: 04/11/2017] [Indexed: 11/29/2022]
Abstract
Glacier ecosystems are teeming with life on, beneath, and to a lesser degree, within their icy masses. This conclusion largely stems from polar research, with less attention paid to mountain glaciers that overlap environmentally and ecologically with their polar counterparts in some ways, but diverge in others. One difference lies in the susceptibility of mountain glaciers to the near-term threat of climate change, as they tend to be much smaller in both area and volume. Moreover, mountain glaciers are typically steeper, more dependent upon basal sliding for movement, and experience higher seasonal precipitation. Here, we provide a modern synthesis of the microbial ecology of mountain glacier ecosystems, and particularly those at low- to mid-latitudes. We focus on five ecological zones: the supraglacial surface, englacial interior, subglacial bedrock-ice interface, proglacial streams and glacier forefields. For each, we discuss the role of microbiota in biogeochemical cycling and outline ecological and hydrological connections among zones, underscoring the interconnected nature of these ecosystems. Collectively, we highlight the need to: better document the biodiversity and functional roles of mountain glacier microbiota; describe the ecological implications of rapid glacial retreat under climate change and resolve the relative contributions of ecological zones to broader ecosystem function.
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Affiliation(s)
- Scott Hotaling
- Department of Biology, University of Kentucky, Lexington, KY, 40506, USA
| | - Eran Hood
- Department of Natural Science, University of Alaska Southeast, Juneau, AK, 99801, USA
| | - Trinity L Hamilton
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
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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: 120] [Impact Index Per Article: 17.1] [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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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: 38] [Impact Index Per Article: 4.8] [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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38
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Achberger AM, Christner BC, Michaud AB, Priscu JC, Skidmore ML, Vick-Majors TJ. Microbial Community Structure of Subglacial Lake Whillans, West Antarctica. Front Microbiol 2016; 7:1457. [PMID: 27713727 PMCID: PMC5032586 DOI: 10.3389/fmicb.2016.01457] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/31/2016] [Indexed: 11/13/2022] Open
Abstract
Subglacial Lake Whillans (SLW) is located beneath ∼800 m of ice on the Whillans Ice Stream in West Antarctica and was sampled in January of 2013, providing the first opportunity to directly examine water and sediments from an Antarctic subglacial lake. To minimize the introduction of surface contaminants to SLW during its exploration, an access borehole was created using a microbiologically clean hot water drill designed to reduce the number and viability of microorganisms in the drilling water. Analysis of 16S rRNA genes (rDNA) amplified from samples of the drilling and borehole water allowed an evaluation of the efficacy of this approach and enabled a confident assessment of the SLW ecosystem inhabitants. Based on an analysis of 16S rDNA and rRNA (i.e., reverse-transcribed rRNA molecules) data, the SLW community was found to be bacterially dominated and compositionally distinct from the assemblages identified in the drill system. The abundance of bacteria (e.g., Candidatus Nitrotoga, Sideroxydans, Thiobacillus, and Albidiferax) and archaea (Candidatus Nitrosoarchaeum) related to chemolithoautotrophs was consistent with the oxidation of reduced iron, sulfur, and nitrogen compounds having important roles as pathways for primary production in this permanently dark ecosystem. Further, the prevalence of Methylobacter in surficial lake sediments combined with the detection of methanogenic taxa in the deepest sediment horizons analyzed (34–36 cm) supported the hypothesis that methane cycling occurs beneath the West Antarctic Ice Sheet. Large ratios of rRNA to rDNA were observed for several operational taxonomic units abundant in the water column and sediments (e.g., Albidiferax, Methylobacter, Candidatus Nitrotoga, Sideroxydans, and Smithella), suggesting a potentially active role for these taxa in the SLW ecosystem. Our findings are consistent with chemosynthetic microorganisms serving as the ecological foundation in this dark subsurface environment, providing new organic matter that sustains a microbial ecosystem beneath the West Antarctic Ice Sheet.
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Affiliation(s)
- Amanda M Achberger
- Department of Biological Sciences, Louisiana State University, Baton Rouge LA, USA
| | - Brent C Christner
- Department of Biological Sciences, Louisiana State University, Baton RougeLA, USA; Department of Microbiology and Cell Science, University of Florida, GainesvilleFL, USA; Biodiversity Institute, University of Florida, GainesvilleFL, USA
| | - Alexander B Michaud
- Department of Land Resources and Environmental Science, Montana State University, Bozeman MT, USA
| | - John C Priscu
- Department of Land Resources and Environmental Science, Montana State University, Bozeman MT, USA
| | - Mark L Skidmore
- Department of Earth Sciences, Montana State University, Bozeman MT, USA
| | - Trista J Vick-Majors
- Department of Land Resources and Environmental Science, Montana State University, Bozeman MT, USA
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39
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Bagshaw EA, Beaton A, Wadham JL, Mowlem M, Hawkings JR, Tranter M. Chemical sensors for in situ data collection in the cryosphere. Trends Analyt Chem 2016. [DOI: 10.1016/j.trac.2016.06.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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40
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Cameron KA, Stibal M, Hawkings JR, Mikkelsen AB, Telling J, Kohler TJ, Gözdereliler E, Zarsky JD, Wadham JL, Jacobsen CS. Meltwater export of prokaryotic cells from the Greenland ice sheet. Environ Microbiol 2016; 19:524-534. [PMID: 27489963 DOI: 10.1111/1462-2920.13483] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 07/31/2016] [Indexed: 11/26/2022]
Abstract
Microorganisms are flushed from the Greenland Ice Sheet (GrIS) where they may contribute towards the nutrient cycling and community compositions of downstream ecosystems. We investigate meltwater microbial assemblages as they exit the GrIS from a large outlet glacier, and as they enter a downstream river delta during the record melt year of 2012. Prokaryotic abundance, flux and community composition was studied, and factors affecting community structures were statistically considered. The mean concentration of cells exiting the ice sheet was 8.30 × 104 cells mL-1 and we estimate that ∼1.02 × 1021 cells were transported to the downstream fjord in 2012, equivalent to 30.95 Mg of carbon. Prokaryotic microbial assemblages were dominated by Proteobacteria, Bacteroidetes, and Actinobacteria. Cell concentrations and community compositions were stable throughout the sample period, and were statistically similar at both sample sites. Based on our observations, we argue that the subglacial environment is the primary source of the river-transported microbiota, and that cell export from the GrIS is dependent on discharge. We hypothesise that the release of subglacial microbiota to downstream ecosystems will increase as freshwater flux from the GrIS rises in a warming world.
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Affiliation(s)
- Karen A Cameron
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350, Copenhagen, Denmark.,Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Marek Stibal
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350, Copenhagen, Denmark.,Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark.,Department of Ecology, Faculty of Science, Charles University, Viničná 7, 128 43, Prague, Czech Republic
| | - Jon R Hawkings
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, BS8 1SS, Bristol, UK
| | - Andreas B Mikkelsen
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Jon Telling
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, BS8 1SS, Bristol, UK
| | - Tyler J Kohler
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 128 43, Prague, Czech Republic
| | - Erkin Gözdereliler
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350, Copenhagen, Denmark.,Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Jakub D Zarsky
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 128 43, Prague, Czech Republic
| | - Jemma L Wadham
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, BS8 1SS, Bristol, UK
| | - Carsten S Jacobsen
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark.,Department of Environmental Science, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark
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41
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Northington RM, Saros JE. Factors Controlling Methane in Arctic Lakes of Southwest Greenland. PLoS One 2016; 11:e0159642. [PMID: 27454863 PMCID: PMC4959701 DOI: 10.1371/journal.pone.0159642] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 07/06/2016] [Indexed: 11/30/2022] Open
Abstract
We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region.
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Affiliation(s)
- Robert M. Northington
- Climate Change Institute, University of Maine, Orono, ME, 04469, United States of America
- * E-mail:
| | - Jasmine E. Saros
- Climate Change Institute, University of Maine, Orono, ME, 04469, United States of America
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42
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Oshkin IY, Belova SE, Danilova OV, Miroshnikov KK, Rijpstra WIC, Sinninghe Damsté JS, Liesack W, Dedysh SN. Methylovulum psychrotolerans sp. nov., a cold-adapted methanotroph from low-temperature terrestrial environments, and emended description of the genus Methylovulum. Int J Syst Evol Microbiol 2016; 66:2417-2423. [DOI: 10.1099/ijsem.0.001046] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Igor Y. Oshkin
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia
| | - Svetlana E. Belova
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia
| | - Olga V. Danilova
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia
| | | | - W. Irene C. Rijpstra
- NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - Jaap S. Sinninghe Damsté
- NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, PO Box 59, 1790 AB Den Burg, The Netherlands
- Utrecht University, Faculty of Geosciences, Department of Earth Sciences, Geochemistry, Utrecht, The Netherlands
| | - Werner Liesack
- Max-Planck-Institut für terrestrische Mikrobiologie, D-35043 Marburg, Germany
| | - Svetlana N. Dedysh
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia
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43
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Mateos-Rivera A, Yde JC, Wilson B, Finster KW, Reigstad LJ, Øvreås L. The effect of temperature change on the microbial diversity and community structure along the chronosequence of the sub-arctic glacier forefield of Styggedalsbreen (Norway). FEMS Microbiol Ecol 2016; 92:fnw038. [DOI: 10.1093/femsec/fiw038] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2016] [Indexed: 11/14/2022] Open
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Boetius A, Anesio AM, Deming JW, Mikucki JA, Rapp JZ. Microbial ecology of the cryosphere: sea ice and glacial habitats. Nat Rev Microbiol 2015; 13:677-90. [PMID: 26344407 DOI: 10.1038/nrmicro3522] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Earth's cryosphere comprises those regions that are cold enough for water to turn into ice. Recent findings show that the icy realms of polar oceans, glaciers and ice sheets are inhabited by microorganisms of all three domains of life, and that temperatures below 0 °C are an integral force in the diversification of microbial life. Cold-adapted microorganisms maintain key ecological functions in icy habitats: where sunlight penetrates the ice, photoautotrophy is the basis for complex food webs, whereas in dark subglacial habitats, chemoautotrophy reigns. This Review summarizes current knowledge of the microbial ecology of frozen waters, including the diversity of niches, the composition of microbial communities at these sites and their biogeochemical activities.
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Affiliation(s)
- Antje Boetius
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.,Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany
| | - Alexandre M Anesio
- Bristol Glaciology Center, School of Geographical Sciences, University of Bristol, BS8 1SS, UK
| | - Jody W Deming
- School of Oceanography, Box 357940, University of Washington, Seattle, Washington 98195, USA
| | - Jill A Mikucki
- Department of Biology, 276 Bicentennial Way, Middlebury College, Middlebury, Vermont 05753, USA
| | - Josephine Z Rapp
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.,Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany
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45
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Panda AK, Bisht SS, Kumar NS, De Mandal S. Report from the 10th International Congress on Extremophiles. GENOMICS DATA 2015. [DOI: 10.1016/j.gdata.2015.07.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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46
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Sheik CS, Stevenson EI, Den Uyl PA, Arendt CA, Aciego SM, Dick GJ. Microbial communities of the Lemon Creek Glacier show subtle structural variation yet stable phylogenetic composition over space and time. Front Microbiol 2015; 6:495. [PMID: 26042114 PMCID: PMC4438255 DOI: 10.3389/fmicb.2015.00495] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 05/05/2015] [Indexed: 11/13/2022] Open
Abstract
Glaciers are geologically important yet transient ecosystems that support diverse, biogeochemically significant microbial communities. During the melt season glaciers undergo dramatic physical, geochemical, and biological changes that exert great influence on downstream biogeochemical cycles. Thus, we sought to understand the temporal melt-season dynamics of microbial communities and associated geochemistry at the terminus of Lemon Creek Glacier (LCG) in coastal southern Alaska. Due to late season snowfall, sampling of LCG occurred in three interconnected areas: proglacial Lake Thomas, the lower glacial outflow stream, and the glacier’s terminus. LCG associated microbial communities were phylogenetically diverse and varied by sampling location. However, Betaproteobacteria, Alphaproteobacteria, and Bacteroidetes dominated communities at all sampling locations. Strict anaerobic groups such as methanogens, SR1, and OP11 were also recovered from glacier outflows, indicating anoxic conditions in at least some portions of the LCG subglacial environment. Microbial community structure was significantly correlated with sampling location and sodium concentrations. Microbial communities sampled from terminus outflow waters exhibited day-to-day fluctuation in taxonomy and phylogenetic similarity. However, these communities were not significantly different from randomly constructed communities from all three sites. These results indicate that glacial outflows share a large proportion of phylogenetic overlap with downstream environments and that the observed significant shifts in community structure are driven by changes in relative abundance of different taxa, and not complete restructuring of communities. We conclude that LCG glacial discharge hosts a diverse and relatively stable microbiome that shifts at fine taxonomic scales in response to geochemistry and likely water residence time.
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Affiliation(s)
- Cody S Sheik
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI USA ; Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI USA
| | - Emily I Stevenson
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI USA
| | - Paul A Den Uyl
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI USA
| | - Carli A Arendt
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI USA
| | - Sarah M Aciego
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI USA
| | - Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI USA ; Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI USA ; Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI USA
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Stibal M, Schostag M, Cameron KA, Hansen LH, Chandler DM, Wadham JL, Jacobsen CS. Different bulk and active bacterial communities in cryoconite from the margin and interior of the Greenland ice sheet. ENVIRONMENTAL MICROBIOLOGY REPORTS 2015; 7:293-300. [PMID: 25405749 DOI: 10.1111/1758-2229.12246] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/19/2014] [Indexed: 06/04/2023]
Abstract
Biological processes in the supraglacial ecosystem, including cryoconite, contribute to nutrient cycling within the cryosphere and may affect surface melting, yet little is known of the diversity of the active microbes in these environments. We examined the bacterial abundance and community composition of cryoconite over a melt season at two contrasting sites at the margin and in the interior of the Greenland ice sheet, using sequence analysis and quantitative polymerase chain reaction of coextracted 16S rDNA and rRNA. Significant differences were found between bulk (rDNA) and potentially active (rRNA) communities, and between communities sampled from the two sites. Higher concentrations of rRNA than rDNA were detected at the interior site, whereas at the margin several orders of magnitude less rRNA was found compared with rDNA, which may be explained by a lower proportion of active bacteria at the margin site. The rRNA communities at both sites were dominated by a few taxa of Cyanobacteria and Alpha- and/or Betaproteobacteria. The bulk alpha diversity was higher in the margin site community, suggesting that local sources may be contributing towards the gene pool in addition to long distance transport.
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Affiliation(s)
- Marek Stibal
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark; Center for Permafrost (CENPERM), University of Copenhagen, Copenhagen, Denmark
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Nunn BL, Slattery KV, Cameron KA, Timmins-Schiffman E, Junge K. Proteomics of Colwellia psychrerythraea at subzero temperatures - a life with limited movement, flexible membranes and vital DNA repair. Environ Microbiol 2015; 17:2319-35. [PMID: 25471130 DOI: 10.1111/1462-2920.12691] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 10/23/2014] [Accepted: 10/23/2014] [Indexed: 11/27/2022]
Abstract
The mechanisms that allow psychrophilic bacteria to remain metabolically active at subzero temperatures result from form and function of their proteins. We present first proteomic evidence of physiological changes of the marine psychrophile Colwellia psychrerythraea 34H (Cp34H) after exposure to subzero temperatures (-1, and -10°C in ice) through 8 weeks. Protein abundance was compared between different treatments to understand the effects of temperature and time, independently and jointly, within cells transitioning to, and being maintained in ice. Parallel [3H]-leucine and [3H]-thymidine incubations indicated active protein and DNA synthesis to -10°C. Mass spectrometry-based proteomics identified 1763 proteins across four experimental treatments. Proteins involved in osmolyte regulation and polymer secretion were found constitutively present across all treatments, suggesting that they are required for metabolic success below 0°C. Differentially abundant protein groups indicated a reallocation of resources from DNA binding to DNA repair and from motility to chemo-taxis and sensing. Changes to iron and nitrogen metabolism, cellular membrane structures, and protein synthesis and folding were also revealed. By elucidating vital strategies during life in ice, this study provides novel insight into the extensive molecular adaptations that occur in cold-adapted marine organisms to sustain cellular function in their habitat.
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Affiliation(s)
- Brook L Nunn
- Department of Genome Sciences, University of Washington, Box 355065, Seattle, WA, 98195, USA
| | - Krystal V Slattery
- Applied Physics Laboratory, Polar Science Center, University of Washington, Box 355640, Seattle, WA, 98195, USA
| | - Karen A Cameron
- Applied Physics Laboratory, Polar Science Center, University of Washington, Box 355640, Seattle, WA, 98195, USA
| | - Emma Timmins-Schiffman
- Department of Genome Sciences, University of Washington, Box 355065, Seattle, WA, 98195, USA
| | - Karen Junge
- Applied Physics Laboratory, Polar Science Center, University of Washington, Box 355640, Seattle, WA, 98195, USA
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