Ancient Microbes Discovered in Antarctic Lake

Scientists from NASA, the Desert Research Institute (DRI) in Reno, Nev., the University of Illinois at Chicago, and nine other institutions, have uncovered a community of bacteria in one of the most remote lakes of Antarctica, nearly 65 feet beneath the icy surface.

Lake Vida, the largest of several unique lakes found in the McMurdo Dry Valleys, contains no oxygen, is mostly frozen and possesses the highest nitrous oxide levels of any natural water body on Earth. A briny liquid, which is approximately six times saltier than seawater, percolates throughout the icy environment where the average temperature is minus 8 degrees Fahrenheit. The international team of scientists published their findings online Nov. 26, in the Proceedings of the National Academy of Sciences Early Edition.

Despite the very cold, dark and isolated nature of the habitat, the report finds the brine harbors a surprisingly diverse and abundant variety of bacteria that survive without a current source of energy from the sun. Previous studies of Lake Vida dating back to 1996 indicate the brine and its inhabitants have been isolated from outside influences for more than 3,000 years.

This discovery of life existing in one of Earth's darkest, saltiest and coldest habitats is significant because it helps increase our limited knowledge of how life can sustain itself in these extreme environments on our own planet and beyond. "This study provides a window into one of the most unique ecosystems on Earth," said Alison Murray, a molecular microbial ecologist and polar researcher at the DRI and the report's lead author. "Our knowledge of geochemical and microbial processes in lightless icy environments, especially at subzero temperatures, has been mostly unknown up until now. This work expands our understanding of the types of life that can survive in these isolated, cryoecosystems and how different strategies may be used to exist in such challenging environments."

"The microbial ecosystem discovered at Lake Vida expands our knowledge of environmental limits for life and helps define new niches of habitability," said Adrian Ponce, co-author from NASA's Jet Propulsion Laboratory, Pasadena, Calif.