for National Geographic News
Some fungi eat radiation to fuel their growth, a new study suggests.
Three species of fungi containing the black pigment melanin—a substance also present in human skin—grew larger and faster when exposed to high levels of radiation, even when deprived of nutrients.
A similar response was not seen in fungi lacking the pigment, as well as in fungi that did not receive the radiation exposure.
Researchers at Albert Einstein College of Medicine at New York's Yeshiva University were inspired by previous observations of enhanced fungus growth inside the Chernobyl Nuclear Power Plant, after a reactor at the Ukrainian facility exploded in 1986.
(See photo gallery: "Chernobyl, 20 Years After the Disaster".)
The team performed a series of experiments to test whether the fungi could be harvesting radiation to fuel their growth, much like plants do when they capture solar energy through photosynthesis.
In addition to faster fungal growth, the researchers noted changes in the electrical structure of the melanin exposed to radiation.
Lead researcher Ekaterina Dadachova said these observations suggest that the pigment may play a role in the fungi similar to that of chlorophyll in plants, which traps energy from sunlight and converts it to "food energy" needed to sustain life.
"We have associated the faster growth caused by radiation with melanin—a phenomenon suggesting that the pigment is somehow involved in harvesting high-energy ionizing radiation" and promoting growth, study co-author Arturo Casadevall of Yeshiva University said.
Duke University fungi expert Rytas Vilgalys, who was not involved in the study, said the new paper is "most interesting, truly original, and highly provocative."
The study by Dadachova's team was published today in the online journal PLoS One.
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