Antarctic mushrooms persist in Martian conditions

Antarctic mushrooms persist in Martian conditions

After living for 18 months in a Mars-like environment outside the International Space Station, some of the Antarctic mushrooms were still alive and propagated by dividing after returning to Earth. This discovery occurred after studying two species of Antarctic mushrooms, as well as lichens from the Sierra de Gredos (Spain) and the Alps (Austria), as part of the experiment with lichens and fungi (LIFE).

The samples were placed on the EXPOSE-E external platform on the ISS in 2009 and left in space for 18 months. Half of the Antarctic mushrooms were exposed to an atmosphere similar to the Martian in an isolated system (mainly carbon dioxide with traces of argon, oxygen, nitrogen and water). Martian radiation was also modeled using optical filters. The remaining lichens were subject to various conditions, such as the natural space environment.

Result? More than 60 percent of the cells of the Antarctic fungi, which usually live in the rocks in the McMurdo Dry Valley, were still alive when they were studied by researchers. But only about 10 percent of those cells could still divide after exposure to Mars-like conditions. Spanish and Alpine lichens also showed more vitality than those living in a space-like environment.

Amazingly, the conclusion is that the likelihood of cell survival would probably decrease if they stayed in Mars-like conditions, said researcher Rosa de la Torre Noetzel from the National Institute of Aerospace Engineering of Spain. This is due to the accumulated dose of extraterrestrial radiation and the simulated composition of the atmosphere of Mars (with a high percentage of CO2), she said via e-mail to Discovery News.

Antarctic mushrooms persist in Martian conditions

From a planetary defense point of view, Rosa de la Torre Noetzel noted, previous space experiments have presented data on some cosmically resistant microbes, such as Bacillus subtilis 168 and Bacillus pumilus SAFR-032. While these disputes can survive in conditions such as vacuum, radiation and temperature fluctuations while traveling to Mars, ultra violet radiation will ultimately kill them if they do not hide in cracks or holes on the surface of the spacecraft.

Landing probes that are protected against these conditions inside thermal protection (for example, all-terrain vehicles) can sustain disputes for long periods of time, thus disputes will be protected during a trip to Mars. In addition, if the planting module is UV protected, spores can live longer. "In this context, crypto-endolytic mushrooms could live for a longer period under Martian ultraviolet irradiation, taking into account the protection of the stone material," she added.

The team prepared a new experiment on a new generation of installation in the external compartment called EXPOSE-R2. The experiment is called Biomex and began in the summer of 2014. The experiment compares the survival of fungi and lichens with other organisms (for example, bacteria, algae and mosses) in space and Mars-like conditions.

Antarctic mushrooms persist in Martian conditions

"This job will start on earth when EXPOSE returns to Earth (July 2016), trying to determine which organism is the most stable, which strategy provides the highest degree of protection in space, and which biological substances will be suitable as markers when looking for life on Mars, "writes Rosa de la Torre Noetzel. “The results will also help determine if they can survive on other planets.” Another recent study showed the absence of microbes in certain Mars-like conditions on Earth. In particular, the researchers did not detect microbial activity in certain parts of the McMurdo Dry Valley, in particular, in the permafrost at a temperature of about -25 degrees Celsius (-13 degrees Fahrenheit). However, in the same region there are sandstone boulders and rocks where microbes were found.

"Comparison of various environmental conditions, in the same place in soils and in rocks, can provide information about the limits that need to be searched for on Mars, which can form the boundaries of the existence of microbes on the planet," writes Silvano Onofri, the principal investigator of the LIFE experiment, electronically mail discovery news.

"In addition, for these reasons, microorganisms isolated from Antarctic rocks can be a model for experiments in space," added Onofri, who is a professor of systematic botany at the University of Tuscany in Italy.

A new study from the LIFE experiment led by Onofri was recently published in Astrobiology.

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