Scientists Discover Ancient Microbes in Salty Antarctic Lake
Scientists have discovered a diverse group of bacteria thriving in the brine of an Antarctic lake that lies beneath 60 feet of ice.
Researchers analyzed Lake Vida, located in the northernmost part of the McMurdo Dry Valleys of East Antarctica, which exists in total darkness with no oxygen supply. Earlier studies revealed that the brine had been isolated from the surface environment for the past 2,800 years.
The research team drilled cores of ice in order to examine the brine. They followed various sanitary procedures and used equipment to avoid contamination.
The team noticed a diverse community of microbes living in the brine with no sunlight and oxygen supply. The brine was yellow and orange in color as it contains compounds laced with iron in it. It is acidic and the salt content is five to six times greater than average ocean water. This keeps the brine from freezing, reported OurAmazingPlanet.
Experts noticed that the temperature was about 8 degrees Fahrenheit (minus 13 degrees Celsius). The microbes have survived in such harsh climatic conditions.
The brine contains high levels of organic carbon, molecular hydrogen, nitrous oxide and both oxidized and reduced compounds. Experts suggested that the chemical reaction between the brine and the underlying sediments could have generated the chemicals. The molecular hydrogen might be providing some of the energy needed for the survival of microbes, they said.
Scientists earlier proposed that living organisms like microbes could possibly thrive in lakes using different sources of chemical energy even if sunlight doesn't penetrate. The new discovery could give insights into how life might have evolved on Earth and functions on other planetary bodies, said Nathaniel Ostrom, zoologist at Michigan State University and co-author of the study.
"The discovery of this ecosystem gives us insight into other isolated, frozen environments on Earth, but it also gives us a potential model for life on other icy planets that harbor saline deposits and subsurface oceans, such as Jupiter's moon Europa," Ostrom said.
Ostrom and his colleagues are further planning to collect samples from the lake to assess the lake's history.
The findings of the study, "Microbial life at -13 °C in the brine of an ice-sealed Antarctic lake," are published in the journal of the Proceedings of the National Academy of Sciences.