Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost
The survival of microorganisms over extended time frames in frozen subsurface environments may be limited by chemical (i.e., via hydrolysis and oxidation) and ionizing radiation-induced damage to chromosomal DNA. In an effort to improve estimates for the survival of bacteria in icy terrestrial and e...
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ftlouisianastuir:oai:digitalcommons.lsu.edu:biosci_pubs-5100 2023-06-11T04:15:55+02:00 Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost Amato, Pierre Doyle, Shawn M Battista, John R Christner, Brent C 2010-10-01T07:00:00Z https://digitalcommons.lsu.edu/biosci_pubs/4094 https://doi.org/10.1089/ast.2010.0477 unknown LSU Digital Commons https://digitalcommons.lsu.edu/biosci_pubs/4094 doi:10.1089/ast.2010.0477 Faculty Publications text 2010 ftlouisianastuir https://doi.org/10.1089/ast.2010.0477 2023-05-28T18:51:31Z The survival of microorganisms over extended time frames in frozen subsurface environments may be limited by chemical (i.e., via hydrolysis and oxidation) and ionizing radiation-induced damage to chromosomal DNA. In an effort to improve estimates for the survival of bacteria in icy terrestrial and extraterrestrial environments, we determined rates of macromolecular synthesis at temperatures down to -15°C in bacteria isolated from Siberian permafrost (Psychrobacter cryohalolentis K5 and P. arcticus 273-4) and the sensitivity of P. cryohalolentis to ionizing radiation. Based on experiments conducted over ≈400 days at -15°C, the rates of protein and DNA synthesis in P. cryohalolentis were <1 to 16 proteins cell(-1) d(-1) and 83 to 150 base pairs (bp) cell(-1) d(-1), respectively; P. arcticus synthesized DNA at rates of 20 to 1625 bp cell(-1) d(-1) at -15°C under the conditions tested. The dose of ionizing radiation at which 37% of the cells survive (D(37)) of frozen suspensions of P. cryohalolentis was 136 Gy, which was ∼2-fold higher (71 Gy) than identical samples exposed as liquid suspensions. Laboratory measurements of [(3)H]thymidine incorporation demonstrate the physiological potential for DNA metabolism at -15°C and suggest a sufficient activity is possible to offset chromosomal damage incurred in near-subsurface terrestrial and martian permafrost. Thus, our data imply that the longevity of microorganisms actively metabolizing within permafrost environments is not constrained by chromosomal DNA damage resulting from ionizing radiation or entropic degradation over geological time. Text permafrost LSU Digital Commons (Louisiana State University) K5 ENVELOPE(24.794,24.794,67.805,67.805) Astrobiology 10 8 789 798 |
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LSU Digital Commons (Louisiana State University) |
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description |
The survival of microorganisms over extended time frames in frozen subsurface environments may be limited by chemical (i.e., via hydrolysis and oxidation) and ionizing radiation-induced damage to chromosomal DNA. In an effort to improve estimates for the survival of bacteria in icy terrestrial and extraterrestrial environments, we determined rates of macromolecular synthesis at temperatures down to -15°C in bacteria isolated from Siberian permafrost (Psychrobacter cryohalolentis K5 and P. arcticus 273-4) and the sensitivity of P. cryohalolentis to ionizing radiation. Based on experiments conducted over ≈400 days at -15°C, the rates of protein and DNA synthesis in P. cryohalolentis were <1 to 16 proteins cell(-1) d(-1) and 83 to 150 base pairs (bp) cell(-1) d(-1), respectively; P. arcticus synthesized DNA at rates of 20 to 1625 bp cell(-1) d(-1) at -15°C under the conditions tested. The dose of ionizing radiation at which 37% of the cells survive (D(37)) of frozen suspensions of P. cryohalolentis was 136 Gy, which was ∼2-fold higher (71 Gy) than identical samples exposed as liquid suspensions. Laboratory measurements of [(3)H]thymidine incorporation demonstrate the physiological potential for DNA metabolism at -15°C and suggest a sufficient activity is possible to offset chromosomal damage incurred in near-subsurface terrestrial and martian permafrost. Thus, our data imply that the longevity of microorganisms actively metabolizing within permafrost environments is not constrained by chromosomal DNA damage resulting from ionizing radiation or entropic degradation over geological time. |
format |
Text |
author |
Amato, Pierre Doyle, Shawn M Battista, John R Christner, Brent C |
spellingShingle |
Amato, Pierre Doyle, Shawn M Battista, John R Christner, Brent C Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost |
author_facet |
Amato, Pierre Doyle, Shawn M Battista, John R Christner, Brent C |
author_sort |
Amato, Pierre |
title |
Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost |
title_short |
Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost |
title_full |
Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost |
title_fullStr |
Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost |
title_full_unstemmed |
Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost |
title_sort |
implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost |
publisher |
LSU Digital Commons |
publishDate |
2010 |
url |
https://digitalcommons.lsu.edu/biosci_pubs/4094 https://doi.org/10.1089/ast.2010.0477 |
long_lat |
ENVELOPE(24.794,24.794,67.805,67.805) |
geographic |
K5 |
geographic_facet |
K5 |
genre |
permafrost |
genre_facet |
permafrost |
op_source |
Faculty Publications |
op_relation |
https://digitalcommons.lsu.edu/biosci_pubs/4094 doi:10.1089/ast.2010.0477 |
op_doi |
https://doi.org/10.1089/ast.2010.0477 |
container_title |
Astrobiology |
container_volume |
10 |
container_issue |
8 |
container_start_page |
789 |
op_container_end_page |
798 |
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1768373153417920512 |