Microbes Identified in Ice-sealed Antarctic Lake

Abundant and diverse metabolically active bacteria have been discovered by scientists in the brine of an Antarctic lake sealed under more than 65 feet of ice.

The finding is surprising because previous studies indicate that the brine has been isolated from the surface environment-and external sources of energy-for at least 2,800 years, according to two of the report's authors, Peter Doran and Fabien Kenig, both professors of earth and environmental sciences at the University of Illinois at Chicago.

Study Sheds Light on How Antarctic Sea Ice Increases With Climate Change
Recent study has shed light on why and how the Antarctic sea ice cover has increased under the effects of climate change.

"This provides us with new boundary conditions on the limits for life," said Doran.

"The low temperature or high salinity on their own are limiting, but combined with an absence of solar energy or any new inputs from the atmosphere, they make this a very tough place to make a living," he stated.

The researchers drilled out cores of ice, using sanitary procedures and equipment. They collected samples of brine within the ice and assessed its chemical qualities and potential for sustaining life.

While Antarctic Grows Arctic Sea Ice Shrinks
The world witnessed two opposite records concerning sea ice last month.

They found that the brine is oxygen-free, slightly acidic, and contains high levels of organic carbon, molecular hydrogen, and both oxidized and reduced compounds. The findings were unexpected because of the extremely salty, dark, cold, isolated ecosystem within the ice.

"Geochemical analyses suggest that chemical reactions between the brine and the underlying sediment generate nitrous oxide and molecular hydrogen. The hydrogen may provide some of the energy needed to support microbes," said Kenig.

Antarctica and Greenland Ice Levels are Rising
The loss of ice due to climate change in Antarctica is causing the once buoyant continent to be heaven-bound.

"We'd like to go back and find if there is a proper body of brine without ice down there," said Doran.

"We'd also like to get some sediment cores from below that to better establish the history of the lake. In the meantime, we are using radar and other geophysical techniques to probe what lies beneath," he added.

Research Says Icebergs in the Antarctic Play Important Role in Carbon Cycle
A team of researchers from UC San Diego and the University of San Diego says that icebergs cool and dilute the ocean water they pass through

The research was conducted with Alison Murray and colleagues at the Desert Research Institute and scientists at other institutes.

The discovery was described in this week's issue of the Proceedings of the National Academy of Sciences.

Source-ANI