The radiation it is the main obstacle difficult to overcome in space exploration missions for astronauts since the propagation of that energy kills cells, damages DNA and causes diseases. A different situation occurs in the Land: the magnetosphere, a layer that deflects the solar wind, protects us.
Through a preprint article uploaded to the Biorxiv platform, researchers from the universities of North Carolina, Mannheim and Stanford have proposed the radiographic fungus Cladosporium sphaerospermum as a new “shield” for space professionals to mitigate the unhealthy effects of the radiation.
Cladosporium sphaerospermum, described since 1886 by the German mycologist Albert Julius Otto Penzig, had already been studied aboard the International Space Station (ISS) for a period of 30 days in 2019, according to the manuscript.
“Certain fungi – including C. sphaerospermum – appear to be capable of using ionizing radiation through a process called radiosynthesis,” the scientists explain.
Radiosynthesis, if we want to understand it better, must be taken as a concept analogous to photosynthesis. Just as plants extract energy from sunlight and generate their own food, this class of mushrooms uses a pigment called melanin in order to block radiation, consume it and grow.
“Over the period of one year, the average person on Earth receives a dose of approximately 6.2 mSv, while the astronaut average on the International Space Station is exposed to an equivalent of approximately 144 mSv; one year after a three-year mission to Mars, an astronaut would have already accumulated about 400 mSv ”, explain the experts at Biorxiv.
MSv stands for milliSievert, the Ionizing Radiation Dose Equivalence Unit of the International System of Units in relation to the health effects of the human body.
This fungus has also thrived in extremely dangerous environments such as around the Vladimir Ilyich Lenin memorial nuclear plant in Chernobyl (Ukraine), where there was a disaster of great proportions in 1986.
“It was found that a microbial turf less than 2 mm thick already decreased measured radiation levels by at least 1.92% and potentially up to 4.84%,” the signatories wrote in the Conclusions section.
In the ISS, the fungus grew 21% faster than on Earth, “which corroborates the thesis that the radiotropism (the increase in roots in association with the amount of radiation) of the fungus is extensible to space radiation” .
The self-replication of fungi in microscopic quantities, as pointed out by researchers Nils Averesch, Christoph Kern, Xavier R. Gómez and Graham K. Shunk, can reduce the amount of investment for missions. They also emphasize that nature – fortunately – and biotechnology will synergize as the life support and protection of explorers in future missions to the Moon, Mars and beyond.