Species in Chernobyl is mutating to ‘feed’ on nuclear radiation

A fungus at the site of the Chernobyl nuclear disaster has adapted to ‘feed’ on levels of radiation that would be fatal to most life forms.

Cladosporium sphaerospermum is a highly resilient black mold that scientists have observed on the walls of reactor number 4, which caused the explosion and fire that destroyed the Chernobyl nuclear power plant in 1986.

Scientists studying the fungus found that it has adapted to use radiation as an energy source, similar to the way plants get energy from the sun.

The Chernobyl disaster was a nuclear meltdown started on April 26 and led to the largest release of radioactive material into the environment in human history.

After the tragic event, people were evacuated from Chernobyl and surrounding areas to avoid the extreme radiation levels.

From then on, the location was known as the Chernobyl Exclusion Zone (CEZ).

The ability of C. sphaerospermum to survive in the CEZ is evidence of how life can emerge even in the harshest and most extreme environments, according to the researchers.

Studying this fugus has revealed ways in which it can be used to protect people from radiation, especially during space missions.

C. sphaerospermum gets its radiation-eating superpower from melanin, the pigment that gives people their skin color.

Previous research published in the journal PLOS One confirmed that C. sphaerospermum can perform radiosynthesis by showing that it grows faster in high-radiation environments.

This laid the foundation for later research published in the journal Current opinion in microbiologythat found that melanin in these fungi absorbs gamma radiation and converts it into chemical energy through a process known as radiosynthesis.

Therefore, it is considered a radiotrophic fungus: ‘radio’ refers to radiation and ‘trophic’ refers to feeding or converting something into usable energy.

In human skin – and that of many other organisms – melanin acts as a shield against harmful UV rays from the sun.

But in these fungi, “it does more than just protect: it facilitates energy production,” evolutionary biologist Scott Travers of Rutgers University wrote in an article for Forbes.

Now scientists think they may be able to harness this superpower to create highly effective radiation shields that could protect astronauts during space missions.

The harsh radioactive environment of space is one of the biggest hurdles to long-term human space missions.

The Chernobyl disaster was a nuclear meltdown that began on April 26 and led to the largest release of radioactive material into the environment in human history.

After the tragic event, people were evacuated from Chernobyl and surrounding areas to avoid the extreme radiation levels. But some organisms survived

According to the European Space Agency (ESA), in just one week on the ISS, astronauts are exposed to the equivalent of one year of exposure on Earth.

On Mars, the radiation environment is even more intense. An astronaut on a mission to Mars could receive radiation doses up to 700 times higher than on our planet, the ESA said.

In a study not yet reviewed by other scientists, researchers aboard the International Space Station (ISS) studied the ability of C. sphaerospermum to attenuate harmful radiation in a radioactive environment similar to the surface of Mars.

The research took place over a period of 26 days and found that the fungus blocked and absorbed 84 percent of space radiation and showed significant growth, indicating that its radiotrophic properties are expandable to space environments.

The study is currently available on the pre-print server bioRxiv.

But C. sphaerospermum could also have some useful applications on Earth.

Studies suggest that this fungus is a powerful bioremediator, meaning it can be used to remove radioactive pollution from the environment.

Cleaning up radioactive sites like the CEZ is both challenging and dangerous, but radiotrophic fungi may provide a safer alternative to human-led cleanup efforts.

Although scientists are still investigating and developing ways to harness radiotrophic fungi for this purpose, studies have shown promising results.

Researchers from the University of Saskatchewan have shown that it is possible to ‘train’ microscopic black fungi to find and weaken sources of radiation. Their research was published in the journal Fungal Biology in 2020.

But C. sphaerospermum isn’t just known for its ability to feed on radiation. It is also uniquely resistant to low temperatures, high salt concentrations and extreme acidity, Travers explains.

“The ability to adapt to hostile environments has given researchers hope that it may hold clues for further research into stress tolerance mechanisms, which could lead to advances in biotechnology and agriculture,” he wrote.

For example, genes responsible for this winter hardiness could be used to develop radiation-resistant materials or breed highly resilient crops, he explained.