Microbial Life beneath a High Arctic Glacier
ABSTRACT The debris-rich basal ice layers of a high Arctic glacier were shown to contain metabolically diverse microbes that could be cultured oligotrophically at low temperatures (0.3 to 4°C). These organisms included aerobic chemoheterotrophs and anaerobic nitrate reducers, sulfate reducers, and m...
Published in: | Applied and Environmental Microbiology |
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American Society for Microbiology
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Online Access: | http://dx.doi.org/10.1128/aem.66.8.3214-3220.2000 https://journals.asm.org/doi/pdf/10.1128/AEM.66.8.3214-3220.2000 |
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crasmicro:10.1128/aem.66.8.3214-3220.2000 2024-09-15T18:11:47+00:00 Microbial Life beneath a High Arctic Glacier Skidmore, Mark L. Foght, Julia M. Sharp, Martin J. 2000 http://dx.doi.org/10.1128/aem.66.8.3214-3220.2000 https://journals.asm.org/doi/pdf/10.1128/AEM.66.8.3214-3220.2000 en eng American Society for Microbiology https://journals.asm.org/non-commercial-tdm-license Applied and Environmental Microbiology volume 66, issue 8, page 3214-3220 ISSN 0099-2240 1098-5336 journal-article 2000 crasmicro https://doi.org/10.1128/aem.66.8.3214-3220.2000 2024-08-26T04:06:40Z ABSTRACT The debris-rich basal ice layers of a high Arctic glacier were shown to contain metabolically diverse microbes that could be cultured oligotrophically at low temperatures (0.3 to 4°C). These organisms included aerobic chemoheterotrophs and anaerobic nitrate reducers, sulfate reducers, and methanogens. Colonies purified from subglacial samples at 4°C appeared to be predominantly psychrophilic. Aerobic chemoheterotrophs were metabolically active in unfrozen basal sediments when they were cultured at 0.3°C in the dark (to simulate nearly in situ conditions), producing 14 CO 2 from radiolabeled sodium acetate with minimal organic amendment (≥38 μM C). In contrast, no activity was observed when samples were cultured at subfreezing temperatures (≤−1.8°C) for 66 days. Electron microscopy of thawed basal ice samples revealed various cell morphologies, including dividing cells. This suggests that the subglacial environment beneath a polythermal glacier provides a viable habitat for life and that microbes may be widespread where the basal ice is temperate and water is present at the base of the glacier and where organic carbon from glacially overridden soils is present. Our observations raise the possibility that in situ microbial production of CO 2 and CH 4 beneath ice masses (e.g., the Northern Hemisphere ice sheets) is an important factor in carbon cycling during glacial periods. Moreover, this terrestrial environment may provide a model for viable habitats for life on Mars, since similar conditions may exist or may have existed in the basal sediments beneath the Martian north polar ice cap. Article in Journal/Newspaper Ice cap ASM Journals (American Society for Microbiology) Applied and Environmental Microbiology 66 8 3214 3220 |
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Open Polar |
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ASM Journals (American Society for Microbiology) |
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crasmicro |
language |
English |
description |
ABSTRACT The debris-rich basal ice layers of a high Arctic glacier were shown to contain metabolically diverse microbes that could be cultured oligotrophically at low temperatures (0.3 to 4°C). These organisms included aerobic chemoheterotrophs and anaerobic nitrate reducers, sulfate reducers, and methanogens. Colonies purified from subglacial samples at 4°C appeared to be predominantly psychrophilic. Aerobic chemoheterotrophs were metabolically active in unfrozen basal sediments when they were cultured at 0.3°C in the dark (to simulate nearly in situ conditions), producing 14 CO 2 from radiolabeled sodium acetate with minimal organic amendment (≥38 μM C). In contrast, no activity was observed when samples were cultured at subfreezing temperatures (≤−1.8°C) for 66 days. Electron microscopy of thawed basal ice samples revealed various cell morphologies, including dividing cells. This suggests that the subglacial environment beneath a polythermal glacier provides a viable habitat for life and that microbes may be widespread where the basal ice is temperate and water is present at the base of the glacier and where organic carbon from glacially overridden soils is present. Our observations raise the possibility that in situ microbial production of CO 2 and CH 4 beneath ice masses (e.g., the Northern Hemisphere ice sheets) is an important factor in carbon cycling during glacial periods. Moreover, this terrestrial environment may provide a model for viable habitats for life on Mars, since similar conditions may exist or may have existed in the basal sediments beneath the Martian north polar ice cap. |
format |
Article in Journal/Newspaper |
author |
Skidmore, Mark L. Foght, Julia M. Sharp, Martin J. |
spellingShingle |
Skidmore, Mark L. Foght, Julia M. Sharp, Martin J. Microbial Life beneath a High Arctic Glacier |
author_facet |
Skidmore, Mark L. Foght, Julia M. Sharp, Martin J. |
author_sort |
Skidmore, Mark L. |
title |
Microbial Life beneath a High Arctic Glacier |
title_short |
Microbial Life beneath a High Arctic Glacier |
title_full |
Microbial Life beneath a High Arctic Glacier |
title_fullStr |
Microbial Life beneath a High Arctic Glacier |
title_full_unstemmed |
Microbial Life beneath a High Arctic Glacier |
title_sort |
microbial life beneath a high arctic glacier |
publisher |
American Society for Microbiology |
publishDate |
2000 |
url |
http://dx.doi.org/10.1128/aem.66.8.3214-3220.2000 https://journals.asm.org/doi/pdf/10.1128/AEM.66.8.3214-3220.2000 |
genre |
Ice cap |
genre_facet |
Ice cap |
op_source |
Applied and Environmental Microbiology volume 66, issue 8, page 3214-3220 ISSN 0099-2240 1098-5336 |
op_rights |
https://journals.asm.org/non-commercial-tdm-license |
op_doi |
https://doi.org/10.1128/aem.66.8.3214-3220.2000 |
container_title |
Applied and Environmental Microbiology |
container_volume |
66 |
container_issue |
8 |
container_start_page |
3214 |
op_container_end_page |
3220 |
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1810449359824748544 |