A team of researchers has uncovered a community of bacteria living in one of the most inhospitable place on Earth: the dark, cold, salty environment under a remote lake in Antarctica. The discovery will help teach scientists how life can be sustained in extreme environments, including places beyond our planet.
Lake Vida, where the discovery took place, lies under nearly 65 feet of ice. It contains no oxygen and possesses the highest concentration of nitrous oxide levels of any natural body of water on Earth. The water is around six times as salty as seawater and has an average temperature of -8 degrees Fahrenheit.
"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 Desert Research Institute (DRI) and lead author of a report on the findings published the National Academy of Sciences Early Edition. "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."
Though previous studies indicate that Lake Vida has been isolated from any outside influences for over 3,000 years, the researchers stated that the habitat is home to a surprisingly diverse and abundant variety of bacteria. The microbes survive without a current source of sunlight.
"This system is probably the best analog we have for possible ecosystems in the subsurface waters of Saturn's moon Enceladus and Jupiter's moon Europa," said Chris McKay, a co-author of the report and senior scientist at NASA's Ames Research Center.
A geochemical analysis of samples from the lake suggest chemical reactions between the briny water and iron-rich sediments produce nitrous oxide and hydrogen, which may provide energy to the microbes.