A hardy bacteria common on Earth was surprisingly adaptive to Mars-like low pressure, cold and carbon dioxide-rich atmosphere, a finding that has implications in the search for extraterrestrial life.
The bacteria, known as Serratia liquefaciens, is found in human skin, hair and lungs, as well as in fish, aquatic systems, plant leaves and roots.
Serratia liquefaciens most likely evolved at sea level, so it was surprising to find it could grow in an experiment chamber that reduced pressure down to a Mars-like 7 millibars, microbiologist Andrew Schuerger said.
Sea-level atmospheric pressure on Earth is about 1,000 millibars or 1 bar.
In addition to concerns that hitchhiking microbes could inadvertently contaminate Mars, the study opens the door to a wider variety of life forms with the potential to evolve indigenously.
To survive, however, the microbes would need to be shielded from the harsh ultraviolet radiation that continually blasts the surface of Mars, as well as have access to a source of water, organic carbon and nitrogen.
So far, efforts to find Earth microbes that could live in the harsh conditions of Mars have primarily focused on so-called extremophiles which are found only in extreme cold, dry or acidic environments on Earth.
The next step is to see how the microbes fare under even more hostile conditions, such as higher salt levels, more radiation and less water.
Related studies to analyze the genetics and metabolism of the common bacteria Serratia liquefaciens also are under way.
“Why is this important?
“We don’t have a Martian bacterium we can experiment with, not yet, so we keep trying to see if some of our own hardy micro-organisms have the ability to grow at another location,” Schuerger said.
“If we can never find a microbe that can grow under conditions on another planet, then it starts implying that life may not exist on that other location,” he said.Reuters