Researchers have found that microbes living in salt survive the unforgiving environment of Deep Lake, Antarctica, by swapping chunks of DNA with each other.
Very few organisms call Deep Lake their home. The lake formed about 3500 years ago when a portion of ocean got isolated after the Antarctic continent rose. The 36-meter deep lake is so salty that it doesn't freeze even when the temperature plummets to minus 20 degrees Celsius.
Haloarchaea, the microbes that live in this environment, fascinate scientists as they take extreme-living to a whole new level. The microbes adapt to the salty conditions by promiscuously exchanging their DNA with microbes of different genus. Genus is a taxonomic classification that's just above species.
"Our research shows these ones swap much more genetic material with each other than has been observed in the natural environment before. Long stretches of virtually identical DNA are exchanged between different genera, not just species," said Professor Rick Cavicchioli, of the UNSW School of Biotechnology and Biomolecular Sciences, according to a news release. "Despite this rampant gene swapping, the different species are maintained and can co-exist because they have evolved to exploit different niches and consume different food sources." Cavicchioli is the lead author of the study.
Some species of haloarchaea break down protein while others consume sugar. Experts say that these organisms grow very slowly, producing just six generations in a year.
The study was conducted by researchers at the University of New South Wales and colleagues. For the study they obtained water samples at depths of five, 13, 24 and 36 meters. They then isolated microbes and studied their entire genome to understand how they live in the lake.
The study is published in the journal Proceedings of the National Academy of Sciences.