November 27, 2012 12:22 pm
Just over a month ago, word came back from a Russian research team that they had failed so far to find life living within the cold Antarctic Lake Vostok, a massive body of water that had been buried beneath glacier ice, effectively cut off from the rest of the world, for the past 15 million years. The lack of life was a blow to those hoping to find that the hardiness of life extended to even the most extreme environments. But now, says Nature, reporting on a new study led by Alison Murray, scientists have found an abundance of life in the frigid Antarctic Lake Vida, a mostly-frozen salt water lake. Unlike Lake Vostok, which is buried beneath thousands of meters of thick glacier ice, Lake Vida is more like a regular lake, just permanently frozen. From drilling missions conducted in 2005 and 2010, the scientists pulled water samples teeming with bacterial life.
Water samples from both trips yielded around one-tenth of the abundance of cells usually found in freshwater lakes in moderate climate zones. Some of the cells measured up to 1 micrometre in diameter — about normal for microbes — but the samples contained many more particles that were around 0.2 micrometres in diameter.
Neither cell type represents a previously unknown life form, says Alison Murray, a microbial environmentalist at the Desert Research Institute in Reno, Nevada, and a co-author of the paper. Genetic analysis suggests that most of the cells — both those of standard size and the microcells — are related to known types of bacterium. However, one abundant bacterium of normal size seems to have no close relatives among cultivated bacteria, and so may represent a new phylum.
There are a number of questions remaining about exactly how the bacteria make it through their daily lives in the hostile lake. The BBC:
Lake Vida, the largest of several unique lakes found in the McMurdo Dry Valleys, contains no oxygen, is acidic, mostly frozen and possesses the highest nitrous oxide levels of any natural water body on Earth.
A briny liquid that is approximately six times saltier than seawater percolates throughout the icy environment.
The water in Lake Vida has been cut off from its surroundings for roughly 2,800 years, nowhere near the 15 million for Lake Vostok or other Antarctic subglacial lakes. But, the fact that things are alive in Lake Vida at all further extends the idea that where there is water, there is life.
More from Smithsonian.com:
No Life Found In Lakes Beneath Antarctic Glaciers—Yet
Top Ten Places Where Life Shouldn’t Exist… But Does
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