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Information - BG7.04 The use of novel methods to examine diversity and physiology of microbes in frozen and liquid aquatic systems
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Event Information |
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Since life as we know it needs liquid water to exist, a clear distinction between repository or storage sites for viable organisms and ice ecosystems (where organisms can not only survive but grow and reproduce) is given. Good knowledge exists about sea ice organisms and snow algae, but other systems such as lake ice, glaciers and water in a supercooled state have been detected only recently. Liquid water exists in many icy systems, however only as a thin film, as a highly concentrated salt solution or in a supercooled state. Although metabolism of microorganisms is lowered at zero or subzero temperatures, they do not inhibit the proliferation of microbial communities. Therefore, active and diverse assemblages of organisms develop in ice and snow covers of distinct geographical regions of the world, and even supercooled cloud droplets, seem to be a suitable site for bacterial growth. This leads to the suggestion that life can be expected everywhere in the cold where liquid water can exist. Ice and snow environments contribute to global biodiversity in at least two ways: first, by largely extending the area of habitats where active life exists and formerly thought to be lifeless or just repositories of dormant cells; secondly by offering a site of interaction between organisms that are otherwise strictly separated into the terrestrial and aquatic sphere. We are still at the beginning of the exploration of snow and ice ecosystems, and wet lack appropriate methodologies to measure activities and growth rates of organisms under in situ conditions and at the solid-liquid-gaseous boundaries of water. Extant knowledge on icy environments, however, let us suggest that, if life will be found on extraterrestrial bodies, there is a good chance that it will occur in association with ice.
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Preliminary List of Solicited Speakers |
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