Active and dormant microorganisms on glacier surfaces

• Published in: Geobiology
• Main Authors: Bradley, James, A, Trivedi, Christopher, B, Winkel, Matthias, Mourot, Rey, Lutz, Stefanie, Larose, Catherine, Keuschnig, Christoph, Doting, Eva, Halbach, Laura, Zervas, Athanasios, Anesio, Alexandre, M, Benning, Liane, G
• Other Authors: Queen Mary University of London (QMUL), GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), Ampère, Département Bioingénierie (BioIng), Ampère (AMPERE), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Freie Universität Berlin, Aarhus University Aarhus
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: activity; dormancy; extremophiles; glacier; ice; microorganisms; snow; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology; Greenland; Ice Sheet; Iceland
• Online Access: https://hal.science/hal-04291424; https://hal.science/hal-04291424/document; https://hal.science/hal-04291424/file/Geobiology%20-%202022%20-%20Bradley%20-%20Active%20and%20dormant%20microorganisms%20on%20glacier%20surfaces.pdf; https://doi.org/10.1111/gbi.12535

Abstract Glacier and ice sheet surfaces host diverse communities of microorganisms whose activity (or inactivity) influences biogeochemical cycles and ice melting. Supraglacial microbes endure various environmental extremes including resource scarcity, frequent temperature fluctuations above and below the freezing point of water, and high UV irradiance during summer followed by months of total darkness during winter. One strategy that enables microbial life to persist through environmental extremes is dormancy, which despite being prevalent among microbial communities in natural settings, has not been directly measured and quantified in glacier surface ecosystems. Here, we use a combination of metabarcoding and metatranscriptomic analyses, as well as cell‐specific activity (BONCAT) incubations to assess the diversity and activity of microbial communities from glacial surfaces in Iceland and Greenland. We also present a new ecological model for glacier microorganisms and simulate physiological state‐changes in the glacial microbial community under idealized (i) freezing, (ii) thawing, and (iii) freeze–thaw conditions. We show that a high proportion (>50%) of bacterial cells are translationally active in‐situ on snow and ice surfaces, with Actinomycetota, Pseudomonadota, and Planctomycetota dominating the total and active community compositions, and that glacier microorganisms, even when frozen, could resume translational activity within 24 h after thawing. Our data suggest that glacial microorganisms respond rapidly to dynamic and changing conditions typical of their natural environment. We deduce that the biology and biogeochemistry of glacier surfaces are shaped by processes occurring over short (i.e., daily) timescales, and thus are susceptible to change following the expected alterations to the melt‐regime of glaciers driven by climate change. A better understanding of the activity of microorganisms on glacier surfaces is critical in addressing the growing concern of climate change in Polar regions, as ...