Detecting microbial populations in places without oxygen and light

Scientists have recently discovered that ancient bacteria live beneath the icy surface of the Antarctic lake

The study was first published in the Proceedings of the National Academy of Sciences (PNAS), two co-authors of the study, Dr. Alison Murray and Dr. Christian Fritsen Desert, Nevada Research Institute (DRI) for See, for the first time, a microbial population exists and adds to life in the dark, salty and almost frozen environment under a band of nearly 20 meters in one of the most isolated lakes of Antarctica.

Vida Lake is the largest of the few lakes in the McMurdo Dry area, free of oxygen, the lake is almost completely frozen and has the highest nitrous oxide concentration of any natural lake on Earth. . Salt water is about 6 times more saline than seawater permeable to icy environments with an average temperature of -13.5 degrees C (equivalent to 8 degrees F).

"This study provides a 'window' to look at one of the most unique ecosystems on Earth , " said Murray, the lead author of the report, the molecular microbiologist. Murray is also a polar researcher for the past 17 years, who participated in 14 expeditions to the South Ocean and the Antarctic continent. "We have almost no knowledge of the localization and microorganisms in light-free ice environments, especially at temperatures close to zero, most of which have not been discovered until now. This study expands our understanding of these life forms that exist in these isolated and frozen ecosystems and that different strategies can be used to survive in such challenging environments. Anybody? '

Lake Vida

Despite the very cold, dark and isolated nature of the habitat, the report shows that seawater contains a surprising and rich variety of bacteria that exist without an energy source from the face. God. Previous studies on Vida Lake as of 1996 indicate that seawater and its habitats have been isolated from outside influences for more than 3,000 years.

Murray and co-authors and collaborators, including key project researchers Dr. Peter Doran of the University of Illinois at Chicago, developed rigorous protocols and specialized equipment for campaigns in 2005. and 2010 of them to sample seawater while avoiding polluting the pristine ecosystem.

To sample environmental researchers working in solid and sterile tents on the lake surface to keep clean positions and equipment as they drill ice cores, collect seawater samples from lakes and later It assesses the chemical properties of water and its ability to provide and maintain life, in addition to describing the diversity of organisms discovered.

Geochemical analyzes suggest that chemical reactions between seawater and iron-rich sediments are below the generation of nitrous oxide and hydrogen molecules. The latter, in part, can provide the energy needed to maintain the life of diverse microorganisms in seawater.

"Perhaps it is true that these microorganisms' life-sustaining energy sources come from chemical reactions between oxygen and ice deficient saline ," explains Fritsen, a researcher on microbiological ecosystems. Fritsen is a research professor at DRI's Earth and Ecosystem Sciences Department.

"If that's a case," Murray said. "This gives us a whole new context to think about how life can be sustained in the icy ecosystems on the earth and in the other icy worlds of the universe."

Murray added, further research is currently underway to analyze chemical interactions, infertility interactions between the seawater of Vida lake and sediments, in addition to investigating microbial populations using Different genome sequencing approaches. These results can help explain the potential for life in extraterrestrial and saltwater environments.

The seawater of Vida Lake also represents an extrapolation ice ecosystem that is easy and suitable for soil, sediment and wetlands, and lakes that lie beneath the Antarctic ice sheet that other polar researchers now Beginners to explore.