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A Low Temperature Limit for Life on Earth
There is no generally accepted value for the lower temperature limit for life on Earth. We present empirical evidence that free-living microbial cells cooling in the presence of external ice will undergo freeze-induced desiccation and a glass transition (vitrification) at a temperature between −10°C...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3686811/ https://www.ncbi.nlm.nih.gov/pubmed/23840425 http://dx.doi.org/10.1371/journal.pone.0066207 |
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author | Clarke, Andrew Morris, G. John Fonseca, Fernanda Murray, Benjamin J. Acton, Elizabeth Price, Hannah C. |
author_facet | Clarke, Andrew Morris, G. John Fonseca, Fernanda Murray, Benjamin J. Acton, Elizabeth Price, Hannah C. |
author_sort | Clarke, Andrew |
collection | PubMed |
description | There is no generally accepted value for the lower temperature limit for life on Earth. We present empirical evidence that free-living microbial cells cooling in the presence of external ice will undergo freeze-induced desiccation and a glass transition (vitrification) at a temperature between −10°C and −26°C. In contrast to intracellular freezing, vitrification does not result in death and cells may survive very low temperatures once vitrified. The high internal viscosity following vitrification means that diffusion of oxygen and metabolites is slowed to such an extent that cellular metabolism ceases. The temperature range for intracellular vitrification makes this a process of fundamental ecological significance for free-living microbes. It is only where extracellular ice is not present that cells can continue to metabolise below these temperatures, and water droplets in clouds provide an important example of such a habitat. In multicellular organisms the cells are isolated from ice in the environment, and the major factor dictating how they respond to low temperature is the physical state of the extracellular fluid. Where this fluid freezes, then the cells will dehydrate and vitrify in a manner analogous to free-living microbes. Where the extracellular fluid undercools then cells can continue to metabolise, albeit slowly, to temperatures below the vitrification temperature of free-living microbes. Evidence suggests that these cells do also eventually vitrify, but at lower temperatures that may be below −50°C. Since cells must return to a fluid state to resume metabolism and complete their life cycle, and ice is almost universally present in environments at sub-zero temperatures, we propose that the vitrification temperature represents a general lower thermal limit to life on Earth, though its precise value differs between unicellular (typically above −20°C) and multicellular organisms (typically below −20°C). Few multicellular organisms can, however, complete their life cycle at temperatures below ∼−2°C. |
format | Online Article Text |
id | pubmed-3686811 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-36868112013-07-09 A Low Temperature Limit for Life on Earth Clarke, Andrew Morris, G. John Fonseca, Fernanda Murray, Benjamin J. Acton, Elizabeth Price, Hannah C. PLoS One Research Article There is no generally accepted value for the lower temperature limit for life on Earth. We present empirical evidence that free-living microbial cells cooling in the presence of external ice will undergo freeze-induced desiccation and a glass transition (vitrification) at a temperature between −10°C and −26°C. In contrast to intracellular freezing, vitrification does not result in death and cells may survive very low temperatures once vitrified. The high internal viscosity following vitrification means that diffusion of oxygen and metabolites is slowed to such an extent that cellular metabolism ceases. The temperature range for intracellular vitrification makes this a process of fundamental ecological significance for free-living microbes. It is only where extracellular ice is not present that cells can continue to metabolise below these temperatures, and water droplets in clouds provide an important example of such a habitat. In multicellular organisms the cells are isolated from ice in the environment, and the major factor dictating how they respond to low temperature is the physical state of the extracellular fluid. Where this fluid freezes, then the cells will dehydrate and vitrify in a manner analogous to free-living microbes. Where the extracellular fluid undercools then cells can continue to metabolise, albeit slowly, to temperatures below the vitrification temperature of free-living microbes. Evidence suggests that these cells do also eventually vitrify, but at lower temperatures that may be below −50°C. Since cells must return to a fluid state to resume metabolism and complete their life cycle, and ice is almost universally present in environments at sub-zero temperatures, we propose that the vitrification temperature represents a general lower thermal limit to life on Earth, though its precise value differs between unicellular (typically above −20°C) and multicellular organisms (typically below −20°C). Few multicellular organisms can, however, complete their life cycle at temperatures below ∼−2°C. Public Library of Science 2013-06-19 /pmc/articles/PMC3686811/ /pubmed/23840425 http://dx.doi.org/10.1371/journal.pone.0066207 Text en © 2013 Clarke et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Clarke, Andrew Morris, G. John Fonseca, Fernanda Murray, Benjamin J. Acton, Elizabeth Price, Hannah C. A Low Temperature Limit for Life on Earth |
title | A Low Temperature Limit for Life on Earth |
title_full | A Low Temperature Limit for Life on Earth |
title_fullStr | A Low Temperature Limit for Life on Earth |
title_full_unstemmed | A Low Temperature Limit for Life on Earth |
title_short | A Low Temperature Limit for Life on Earth |
title_sort | low temperature limit for life on earth |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3686811/ https://www.ncbi.nlm.nih.gov/pubmed/23840425 http://dx.doi.org/10.1371/journal.pone.0066207 |
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