ATHENS, Ga., April 27 (UPI) — A U.S.-led team of biogeochemists says it has discovered a previously unreported chemical mechanism that produces nitrous oxide, a greenhouse gas.
The researchers led by the University of Georgia Professor Samantha Joye said they made their discovery at Don Juan Pond in Antarctica — a pond that’s 18 times saltier than the Earth’s oceans and virtually never freezes, even in temperatures of less than minus 40 degrees Fahrenheit.
“The pond’s soils and brines and the surrounding rock types are similar to those found on Mars,” Joye said. “So it provides an ideal location to assess microbial activity in extreme environments. While we didn’t detect any ‘bio-gases’ such as hydrogen sulfide and methane, we did, surprisingly, measure high concentrations of nitrous oxide, which is normally an indicator of microbial activity.”
She said her team found a suite of brine-rock reactions that generate a variety of products, including nitrous oxide and hydrogen.
“This novel mechanism may occur in other environments on Earth as well and could serve as both an important component of the martian nitrogen cycle and a source of fuel (hydrogen) to support microbial chemosynthesis,” she said.
Joye said the findings also suggest the reaction of brine-derived nitrates with basaltic rock could be a previously unrecognized means for mobilizing nitrate from surface soils and returning it to the martian atmosphere as nitrous oxide.
The study appears in the journal Nature Geoscience.
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