Microbes extracted from surface sediments near Lost Hammer Spring, Canada, about 900 km south of the North Pole, could provide a model for the type of life forms that may have existed, or still exist, on Mars. Credit: Elisse Magnuson.
The extremely salty, very cold, and almost oxygen-free environment under the permafrost of Lost Hammer Spring in the Canadian Arctic is what most resembles certain areas of Mars. So if you want to learn more about the types of life forms that may have existed, or may still exist, on Mars, this is a good place to look. After many searches in extremely difficult conditions, researchers at McGill University have found microbes that had never been identified before. In addition, through the use of state-of-the-art genomic techniques, they have been able to know their metabolisms.
In a recent article on ISME magazine, scientists show, for the first time, that microbial communities in the Canadian Arctic, under conditions similar to those on Mars, can survive by eating and breathing simple inorganic compounds of a type that has been detected in Mars (such as methane, sulfur, sulfate, carbon monoxide, and carbon dioxide). This finding is so compelling that the European Space Agency selected samples from the surface sediments of Lost Hammer to test the life-detection capabilities of the instruments they plan to use at the upcoming ExoMars mission.
Developing a plan for life on Mars
Lost Hammer Spring in Nunavut, Canada’s Arctic is one of the coldest, saltiest land springs ever discovered. The water that flows 600 meters of permafrost to the surface is extremely salty (~ 24% salinity), perpetually at sub-zero temperatures (~ -5 ° C) and contains almost no oxygen (aquatic habitat even at low temperatures). zero). These conditions are similar to those found in certain areas of Mars, where widespread salt deposits and possible cold salt springs have been observed. And although previous studies have found evidence of microbes in this type of environment similar to Mars, this is one of the very few studies to find living and active microbes.
For information on the types of life forms that could exist on Mars, a McGill University research team led by Lyle Whyte of the Department of Natural Resources Sciences has used state-of-the-art genomic tools and microbiology methods. unique cell to identify and characterize a new and, more importantly, an active microbial community in this unique spring. Finding the microbes and then sequencing their DNA and mRNA was no easy task.
It takes an unusual way of life to survive in difficult conditions
“It took a couple of years to work with the sediment before it could successfully detect active microbial communities,” says Dr. Elisse Magnuson. studying in Whyte’s lab and the first author of the paper. “The salinity of the environment interferes with both the extraction and sequencing of microbes, so when we were able to find evidence of active microbial communities, it was a very satisfying experience.”
The team isolated and sequenced the DNA from the spring community, allowing them to reconstruct genomes from about 110 microorganisms, most of which had never been seen before. These genomes have allowed the team to determine how these creatures survive and thrive in this unique extreme environment, acting as blueprints for possible life forms in similar environments. Through mRNA sequencing, the team was able to identify genes active in the genomes and essentially identify some very unusual microbes that are actively metabolized in the extreme spring environment.
No need for organic material to sustain life
“The microbes we found and described in Lost Hammer Spring are amazing, because unlike other microorganisms, they don’t depend on organic matter or oxygen to live,” Whyte adds. “Instead, they survive by eating and breathing simple inorganic compounds such as methane, sulfides, sulfates, carbon monoxide, and carbon dioxide, all of which are found on Mars. They can also fix carbon dioxide and nitrogen gases in the atmosphere. which makes them highly adapted both to survive and to thrive in very extreme environments on Earth and beyond. “
The next steps in the research will be to cultivate and further characterize the most abundant and active members of this strange microbial ecosystem, to better understand why and how they thrive in very cold, salty mud and from the source of lost hammers. Researchers hope that this, in turn, will help interpret the exciting but enigmatic isotopes of sulfur and carbon that were obtained very recently from NASA’s Curiosity Rover in Mars’ Gale crater.
Astrophysicists are investigating the possibility of life beneath the surface of Mars. More information: Elisse Magnuson et al, Lithoautotrophic and oxidizing active microbial community of methane in an anoxic, sub-zero, hypersaline Arctic spring ISME magazine (2022). DOI: 10.1038 / s41396-022-01233-8 Provided by McGill University
Quote: A plan for life forms on Mars? (2022, June 21) Retrieved June 21, 2022 from
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