Radiation Eating Fungi, Food for Astronauts?

Mushrooms are not only tasty but they have remarkable properties. Now researchers have found that dark-colored fungi can even "feed" with radiation, using its energy.

This type of fungus could be employed from more efficient solar cells to feeding astronauts in space, while explaining why sunbaths are so beneficial. The fungi possess the same pigment as people and vertebrates, melanin, that confers both skin and truffles the dark color.

"Just as the pigment chlorophyll converts sunlight into chemical energy that allows green plants to live and grow, our research suggests that melanin can use a different portion of the electromagnetic spectrum - ionizing radiation - to benefit the fungi containing it," said Ekaterina Dadachova of the Albert Einstein College of Medicine in New York.

"It's pure speculation but not outside the realm of possibility that melanin could be providing energy to skin cells," said Arturo Casadevall, chair of microbiology and immunology at Einstein.

Casadevall was intrigued by the fact that fungi were encountered thriving in and around the reactor at Chernobyl, closed and heavily contaminated by the famous 1986 accident, the most severe in the history of the nuclear power.

"It gave us the idea that maybe fungi use melanin to harness radiation," said Casadevall.

His team exposed cultures of fungi, some with melanin and others lacking it, to gamma radiation, the most dangerous radiation emitted by an atomic explosion. They found that the dark fungi in fact grew better when exposed to radiation.

"It raises the possibility that there are pigments out there that allow us to capture a lot of energy," Casadevall said.

In the end, many life forms do not rely on the sun's energy: sulfur-eating bacteria and extremophiles found deep beneath the sea or under Antarctic ice use magnetic or chemical energy.

"Perhaps fungi can live in seemingly inhospitable places as well, so long as there is some radiation. It shows you how nature is resilient and resourceful. Nature can use an energy source wherever it can find it," said Casadevall said.

The radiation-loving fungi could be a food source for astronauts during long space journeys.

"Fungi do very well in dark damp places and you could imagine that space is totally radioactive," Casadevall said.