Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community
Indigenous bacteria and biomolecules (DNA and proteins) in a freeze-dried and homogenized Arctic permafrost were exposed to simulated martian conditions that correspond to about 80 days on the surface of Mars with respect to the accumulated UV dose. The simulation conditions included UV radiation, f...
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2009
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ftalborgunivpubl:oai:pure.atira.dk:publications/abb022c0-3023-11df-aeaf-000ea68e967b 2024-06-23T07:50:49+00:00 Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community Hansen, Aviaja Anna Jensen, Lars Liengård Kristoffersen, Tommy Mikkelsen, Karina Aarup Merrison, Jonathan P. Finster, Kai Lomstein, Bente Aagaard 2009 application/pdf https://vbn.aau.dk/da/publications/abb022c0-3023-11df-aeaf-000ea68e967b https://doi.org/10.1089/ast.2008.0244 https://vbn.aau.dk/ws/files/59468356/Hansen_et_al_2009.pdf eng eng https://vbn.aau.dk/da/publications/abb022c0-3023-11df-aeaf-000ea68e967b info:eu-repo/semantics/restrictedAccess Hansen , A A , Jensen , L L , Kristoffersen , T , Mikkelsen , K A , Merrison , J P , Finster , K & Lomstein , B A 2009 , ' Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community ' , Astrobiology , vol. 9 , no. 2 , pp. 229-240 . https://doi.org/10.1089/ast.2008.0244 article 2009 ftalborgunivpubl https://doi.org/10.1089/ast.2008.0244 2024-06-10T14:39:14Z Indigenous bacteria and biomolecules (DNA and proteins) in a freeze-dried and homogenized Arctic permafrost were exposed to simulated martian conditions that correspond to about 80 days on the surface of Mars with respect to the accumulated UV dose. The simulation conditions included UV radiation, freeze-thaw cycles, the atmospheric gas composition, and pressure. The homogenized permafrost cores were subjected to repeated cycles of UV radiation for 3 h followed by 27 h without irradiation. The effects of the simulation conditions on the concentrations of biomolecules; numbers of viable, dead, and cultured bacteria; as well as the community structure were determined. Simulated martian conditions resulted in a significant reduction of the concentrations of DNA and amino acids in the uppermost 1.5 mm of the soil core. The total number of bacterial cells was reduced in the upper 9 mm of the soil core, while the number of viable cells was reduced in the upper 15 mm. The number of cultured aerobic bacteria was reduced in the upper 6 mm of the soil core, whereas the community structure of cultured anaerobic bacteria was relatively unaffected by the exposure conditions. As explanations for the observed changes, we propose three causes that might have been working on the biological material either individually or synergistically: (i) UV radiation, (ii) UV-generated reactive oxygen species, and (iii) freeze-thaw cycles. Currently, the production and action of reactive gases is only hypothetical and will be a central subject in future investigations. Overall, we conclude that in a stable environment (no wind-/pressure-induced mixing) biological material is efficiently shielded by a 2 cm thick layer of dust, while it is relatively rapidly destroyed in the surface layer, and that biomolecules like proteins and polynucleotides are more resistant to destruction than living biota. Article in Journal/Newspaper Arctic permafrost Aalborg University's Research Portal Arctic Astrobiology 9 2 229 240 |
institution |
Open Polar |
collection |
Aalborg University's Research Portal |
op_collection_id |
ftalborgunivpubl |
language |
English |
description |
Indigenous bacteria and biomolecules (DNA and proteins) in a freeze-dried and homogenized Arctic permafrost were exposed to simulated martian conditions that correspond to about 80 days on the surface of Mars with respect to the accumulated UV dose. The simulation conditions included UV radiation, freeze-thaw cycles, the atmospheric gas composition, and pressure. The homogenized permafrost cores were subjected to repeated cycles of UV radiation for 3 h followed by 27 h without irradiation. The effects of the simulation conditions on the concentrations of biomolecules; numbers of viable, dead, and cultured bacteria; as well as the community structure were determined. Simulated martian conditions resulted in a significant reduction of the concentrations of DNA and amino acids in the uppermost 1.5 mm of the soil core. The total number of bacterial cells was reduced in the upper 9 mm of the soil core, while the number of viable cells was reduced in the upper 15 mm. The number of cultured aerobic bacteria was reduced in the upper 6 mm of the soil core, whereas the community structure of cultured anaerobic bacteria was relatively unaffected by the exposure conditions. As explanations for the observed changes, we propose three causes that might have been working on the biological material either individually or synergistically: (i) UV radiation, (ii) UV-generated reactive oxygen species, and (iii) freeze-thaw cycles. Currently, the production and action of reactive gases is only hypothetical and will be a central subject in future investigations. Overall, we conclude that in a stable environment (no wind-/pressure-induced mixing) biological material is efficiently shielded by a 2 cm thick layer of dust, while it is relatively rapidly destroyed in the surface layer, and that biomolecules like proteins and polynucleotides are more resistant to destruction than living biota. |
format |
Article in Journal/Newspaper |
author |
Hansen, Aviaja Anna Jensen, Lars Liengård Kristoffersen, Tommy Mikkelsen, Karina Aarup Merrison, Jonathan P. Finster, Kai Lomstein, Bente Aagaard |
spellingShingle |
Hansen, Aviaja Anna Jensen, Lars Liengård Kristoffersen, Tommy Mikkelsen, Karina Aarup Merrison, Jonathan P. Finster, Kai Lomstein, Bente Aagaard Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community |
author_facet |
Hansen, Aviaja Anna Jensen, Lars Liengård Kristoffersen, Tommy Mikkelsen, Karina Aarup Merrison, Jonathan P. Finster, Kai Lomstein, Bente Aagaard |
author_sort |
Hansen, Aviaja Anna |
title |
Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community |
title_short |
Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community |
title_full |
Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community |
title_fullStr |
Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community |
title_full_unstemmed |
Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community |
title_sort |
effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community |
publishDate |
2009 |
url |
https://vbn.aau.dk/da/publications/abb022c0-3023-11df-aeaf-000ea68e967b https://doi.org/10.1089/ast.2008.0244 https://vbn.aau.dk/ws/files/59468356/Hansen_et_al_2009.pdf |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic permafrost |
genre_facet |
Arctic permafrost |
op_source |
Hansen , A A , Jensen , L L , Kristoffersen , T , Mikkelsen , K A , Merrison , J P , Finster , K & Lomstein , B A 2009 , ' Effects of long-term simulated martian conditions on a freeze-dried and homogenized bacterial permafrost community ' , Astrobiology , vol. 9 , no. 2 , pp. 229-240 . https://doi.org/10.1089/ast.2008.0244 |
op_relation |
https://vbn.aau.dk/da/publications/abb022c0-3023-11df-aeaf-000ea68e967b |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1089/ast.2008.0244 |
container_title |
Astrobiology |
container_volume |
9 |
container_issue |
2 |
container_start_page |
229 |
op_container_end_page |
240 |
_version_ |
1802641739829215232 |