Life goes on, but it may have to go on without us.
Black Fungus Eats Harmful Radiation in Chernobyl
Fungus living in the walls of a failed nuclear reactor in Chernobyl was found with high melanin content, implying it survived living under dangerous radiation. Fungus might be a possible food source in high-radiation places like outer space.
Black fungus was found growing on the walls of Chernobyl’s damaged and highly radioactive nuclear reactor by robots sent to scour the area. Later, scientists analyzed the fungus and found it contained high content of melanin, a pigment found in human skin that gives it color, as well as protection from solar and ultraviolet radiation.
Melanin is found in many fungal species. Scientists say the melanin found in fungus and humans are similar in chemical composition.
Nuclear (and other high-energy) reactions give off ionizing radiation, dangerous rays and particles that can damage genes and thus cause mutations and eventually cancer. With fungi, however, they seem to thrive under the same conditions.
Ekaterina Dadachova at the Albert Einstein College of Medicine explained the reason why fungi thrived in Chernobyl: She said just like pigment, chlorophyll converts sunlight into chemical energy that allows green plants to live and grow. The melanin helps fungi to make use of the ionizing radiation and makes them grow.
Researcher Arturo Casadevall, an immunologist at the Albert Einstein College of Medicine in New York said to LiveScience.com: "In general we think of radiation as something bad or harmful. Here we have a situation where these fungi appear to benefit, which is unexpected,"
So, the researchers wanted to test this theory and see whether it is reproducible. They did experiments on three species of fungi and found that ionizing radiation significantly boosted the growth of fungi that contained melanin.
As LiveScience.com reports: The researchers exposed two kinds of fungi – one that naturally contained melanin (Wangiella dermatitidis) and another that scientists induced to make the pigment (Crytococcus neoformans) – to levels of ionizing radiation about 500 times higher than normal, the doses one might see at high altitudes. Both species grew significantly faster, findings detailed in the May 23 issue of the journal PLoS ONE.
Although fungi seem to thrive in nuclear radiation, they do not clean it. They are only able to harness the energy that radioactive materials give off.
Scientists say this ability of fungi to live off ionizing radiation could be useful in space. Dadachova said: "Since ionizing radiation is prevalent in outer space, astronauts might be able to rely on fungi as an inexhaustible food source on long missions or for colonizing other planets."
