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Posted by on Nov 27, 2012 in Science |

Lake Life: bacteria that have survived a complete isolation from 2800 years ago

Lake Life: bacteria that have survived a complete isolation from 2800 years ago

In Victoria Valley, north of McMurdo in the Antarctic continent is Lake Vida. With a salinity seven times higher than the sea, a dark and thirteen degrees below zero, this lake has been buried for 2800 years at 20 meters under ice. Full enclosure where a group of U.S. scientists has found bacteria living under the ice, without light or oxygen .

A discovery that has helped researchers to reinforce the idea that there might be some kind of life in other similar environments in our solar system could exist on planets like Mars or Europa, a moon of Jupiter.

According to Peter Doran, University of Illinois and co-leader of the current research in the dry valleys of Antarctica:

Lake Vida is a model of what happens when a lake is frozen solid, and this is the fate of what would have happened in the lakes of Mars, when the planet became colder in the past. Each body of water that formed on Mars would have gone through this stage of life before freezing lake, burying the evidence of past ecosystem.

of Life, brought to the surface in cores drilled 27 meters deep, belong to previously unknown species. Probably survived by metabolism of large amounts of hydrogen and nitrogen oxide gas as they provided the chemical energy source for the existence of this strange ecosystem microbiótico. To Alison Murray, co-leader of the study with Peter Doran:

We are investigating some of the removed cells in the laboratory. We can use these cultured organisms to better understand the physical and chemical extremes that can be tolerated in other icy worlds like the moon Europa.

And according to researchers, it was surprising to find both oxide of hydrogen, nitrogen and carbon in the water. They speculate that these substances can originate from reactions between salt and nitrogen-containing minerals in the rock. Through the centuries, the bacteria without sunlight could have evolved to be totally dependent on these substances for energy. According to Murray:

I think the unusual conditions found in the lake have probably played an important role in shaping the diversity and possibilities of life we find.

Still, the existence of life on the lake does not necessarily increase the likelihood that life exists on other sites even older. In particular scientists refer to lakes Vostok and Ellsworth in Antarctica. Both are 3 miles deep and have been isolated for thousands of years:

Do not give us clues about whether there is life in Vostok and Ellsworth, but it does tell us that in these conditions of large quantities of salt, life can exist.

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