Mold in space can tolerate very high doses of radiation

New research has discovered that the mold found on the International Space Station is able to tolerate very high doses of radiation.

Spores of the two most common types of mold on the ISS, Aspergillus and Pennicillium, survive X-ray exposure at 200 times the dose that would kill a human, according to Marta Cortesão, a microbiologist at the German Aerospace Center (DLR) in Cologne, who will present the new research Friday at the 2019 Astrobiology Science Conference (AbSciCon 2019).

Pennicillium and Aspergillus species are not usually harmful, but inhaling their spores in large amounts can sicken people with weakened immune systems. Mold spores can withstand extreme temperatures, ultraviolet light, chemicals and dry conditions. This resiliency makes them hard to kill.

“We now know that [fungal spores] resist radiation much more than we thought they would, to the point where we need to take them into consideration when we are cleaning spacecraft, inside and outside,” Cortesao said. “If we’re planning a long duration mission, we can plan on having these mold spores with us because probably they will survive the space travel.”

While these findings likely mean an increase in the cost for sterilizing future planetary probes, they also mean that fungi will be available for future space travelers for the production of antibiotics, food, and other useful items.

Antarctic fungi survive Martian conditions on ISS

A European experiment on ISS has found that fungi from Antarctica can survive in a Mars-like environment.

For 18 months half of the Antarctic fungi were exposed to Mars-like conditions. More specifically, this is an atmosphere with 95% CO2, 1.6% argon, 0.15% oxygen, 2.7% nitrogen and 370 parts per million of H2O; and a pressure of 1,000 pascals. Through optical filters, samples were subjected to ultra-violet radiation as if on Mars (higher than 200 nanometres) and others to lower radiation, including separate control samples. “The most relevant outcome was that more than 60% of the cells of the endolithic communities studied remained intact after ‘exposure to Mars’, or rather, the stability of their cellular DNA was still high,” highlights Rosa de la Torre Noetzel from Spain’s National Institute of Aerospace Technology (INTA), co-researcher on the project.

Does this prove that life exists on Mars? Not at all (though I wouldn’t be surprised if we see news articles in the mainstream press over the next week suggesting exactly that). It does show us once again that life is resilient and could develop in many very extreme environments.