Ancient microbes have been discovered in bitter-cold brine beneath 60 feet of Antarctic ice, in permanent darkness and subzero temperatures of Antarctica’s Lake Vida, located in the northernmost of the McMurdo Dry Valleys of East Antarctica.
On the Earth’s surface, water fuels life. Plants use photosynthesis to derive energy. In contrast, at thermal vents at the ocean bottom, out of reach of the sun’s rays, chemical energy released by hydrothermal processes supports life. Life in Lake Vida lacks sunlight and oxygen. Its high concentrations of hydrogen gas, nitrate, nitrite and nitrous oxide likely provide the chemical energy used to support this novel and isolated microbial ecosystem. The high concentrations of hydrogen and nitrous oxide gases are likely derived from chemical reactions with the surrounding iron-rich rocks.
Consequently, it is likely that the chemical reactions between the anoxic brine and rock provide a source of energy to fuel microbial metabolism. These processes provide new insights into how life may have developed on Earth and function on other planetary bodies, Ostrom said. The research team comprised scientists from the Desert Research Institute (Reno, Nev.), the University of Illinois-Chicago, NASA, the University of Colorado, the Jet Propulsion Laboratory, Montana State University, the University of Georgia, the University of Tasmania and Indiana University.
For more information: “Microbial life at −13 °C in the brine of an ice-sealed Antarctic lake,” by Alison E. Murray et al. PNAS, 2012. http://www.pnas.org/content/early/2012/11/21/1208607109.abstract Journal reference: Proceedings of the National Academy of Sciences.