Stevenson, Andrew and Burkhardt, Jürgen and Cockell, Charles S and Cray, Jonathan A and Dijksterhuis, Jan and Fox‐Powell, Mark and Kee, Terence P and Kminek, Gerhard and McGenity, Terry J and Timmis, Kenneth N and Timson, David J and Voytek, Mary A and Westall, Frances and Yakimov, Michail M and Hallsworth, John E (2015) Multiplication of microbes below 0.690 water activity: implications for terrestrial and extraterrestrial life. Environmental Microbiology, 17 (2). pp. 257-277. DOI https://doi.org/10.1111/1462-2920.12598
Stevenson, Andrew and Burkhardt, Jürgen and Cockell, Charles S and Cray, Jonathan A and Dijksterhuis, Jan and Fox‐Powell, Mark and Kee, Terence P and Kminek, Gerhard and McGenity, Terry J and Timmis, Kenneth N and Timson, David J and Voytek, Mary A and Westall, Frances and Yakimov, Michail M and Hallsworth, John E (2015) Multiplication of microbes below 0.690 water activity: implications for terrestrial and extraterrestrial life. Environmental Microbiology, 17 (2). pp. 257-277. DOI https://doi.org/10.1111/1462-2920.12598
Stevenson, Andrew and Burkhardt, Jürgen and Cockell, Charles S and Cray, Jonathan A and Dijksterhuis, Jan and Fox‐Powell, Mark and Kee, Terence P and Kminek, Gerhard and McGenity, Terry J and Timmis, Kenneth N and Timson, David J and Voytek, Mary A and Westall, Frances and Yakimov, Michail M and Hallsworth, John E (2015) Multiplication of microbes below 0.690 water activity: implications for terrestrial and extraterrestrial life. Environmental Microbiology, 17 (2). pp. 257-277. DOI https://doi.org/10.1111/1462-2920.12598
Abstract
<jats:title>Summary</jats:title><jats:p>Since a key requirement of known life forms is available water (water activity; <jats:italic>a</jats:italic><jats:sub>w</jats:sub>), recent searches for signatures of past life in terrestrial and extraterrestrial environments have targeted places known to have contained significant quantities of biologically available water. However, early life on <jats:styled-content style="fixed-case">E</jats:styled-content>arth inhabited high‐salt environments, suggesting an ability to withstand low water‐activity. The lower limit of water activity that enables cell division appears to be ∼ 0.605 which, until now, was only known to be exhibited by a single eukaryote, the sugar‐tolerant, fungal xerophile <jats:italic><jats:styled-content style="fixed-case">X</jats:styled-content>eromyces bisporus</jats:italic>. The first forms of life on <jats:styled-content style="fixed-case">E</jats:styled-content>arth were, though, prokaryotic. Recent evidence now indicates that some halophilic <jats:styled-content style="fixed-case">A</jats:styled-content>rchaea and <jats:styled-content style="fixed-case">B</jats:styled-content>acteria have water‐activity limits more or less equal to those of <jats:italic><jats:styled-content style="fixed-case">X</jats:styled-content>. bisporus</jats:italic>. We discuss water activity in relation to the limits of <jats:styled-content style="fixed-case">E</jats:styled-content>arth's present‐day biosphere; the possibility of microbial multiplication by utilizing water from thin, aqueous films or non‐liquid sources; whether prokaryotes were the first organisms able to multiply close to the 0.605‐a<jats:sub>w</jats:sub> limit; and whether extraterrestrial aqueous milieux of ≥ 0.605 <jats:italic>a</jats:italic><jats:sub>w</jats:sub> can resemble fertile microbial habitats found on Earth.</jats:p>
Item Type: | Article |
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Uncontrolled Keywords: | Prokaryotic Cells; Bacteria; Ascomycota; Archaea; Sodium Chloride; Water; Exobiology; Water Microbiology; Ecosystem; Extraterrestrial Environment; Cell Division; Salinity |
Subjects: | Q Science > QH Natural history > QH301 Biology |
Divisions: | Faculty of Science and Health Faculty of Science and Health > Life Sciences, School of |
SWORD Depositor: | Unnamed user with email elements@essex.ac.uk |
Depositing User: | Unnamed user with email elements@essex.ac.uk |
Date Deposited: | 15 Oct 2014 10:58 |
Last Modified: | 30 Oct 2024 20:02 |
URI: | http://repository.essex.ac.uk/id/eprint/10856 |