2007-09-22 13:33:30
There has been an exciting new biological discovery inside the tomb of the Chernobyl reactor. Like out of some B-grade sci fi movie, a robot sent into the reactor discovered a thick coat of black slime growing on the walls. Since it is highly radioactive in there, scientists didn t expect to find anything living, let alone thriving. The robot was instructed to obtain samples of the slime, which it did, and upon examination the slime was even more amazing than was thought at first glance.
This slime, a collection of several fungi actually, was more than just surviving in a radioactive environment, it was actually using gamma radiation as a food source. Samples of these fungi grew significantly faster when exposed to gamma radiation at 500 times the normal background radiation level. The fungi appear to use melanin, a chemical found in human skin as well, in the same fashion as plants use chlorophyll. That is to say, the melanin molecule gets struck by a gamma ray and its chemistry is altered. This is an amazing discovery, no one had even suspected that something like this was possible.
Aside from its novelty value, this discovery leads to some interesting speculation and potential research. Humans have melanin molecules in their skin cells, does this mean that humans are getting some of their energy from radiation? This also implies there could be organisms living in space where ionizing radiation is plentiful. I ve always been a big panspermia proponent, the idea that life did not originate on Earth but is actually common in the cosmos. Organisms that can live in space certainly gives more credence to this idea.
Possibly this could also be used to create plants or mushrooms that could grow in space, serving as a food source for space travellers. Maybe these fungi could be modified and used somehow to clean up radiation contaminated environments. There s quite a few of those, in fact the disposal of radioactive waste is still a huge and unsolved problem. Now the fungi couldn t actually eat the radioactive isotopes, I m not saying that, but if they can live in radioactive environments they might be used to somehow scour out or concentrate the radioactive isotopes in such a way as to facilitate their clean up.
Imagine, there s fallout from a nuclear accident and what do the guys in suits do? They show up, spray mushroom spores over everything, and a few weeks later the mushrooms are harvested and disposed of while the contaminated area is now radiation free. It would certainly be useful, the picture at the top shows the still abandoned town of Priyat, Ukraine. It was built to house the workers at the Chernobyl nuclear power plant, and was evacuated within hours of the accident.
An excellent story about the Chernobyl disaster and Pripyat is at the Ghost Town link. Just be aware that, no, Elana didn t actually ride her motorcycle through the radiation contaminated zone, that was poetic license on her part. (Motorcycle enthusiasts have motorcycled across Europe hoping to duplicate her tour, only to be told by the guards that that motorcycles are not allowed in the contaminated zone.) The pictures and descriptions are accurate though, some of the images are incredibly poignant. Just think, a whole town where the inhabitants fled without warning, leaving all of their possessions behind.
Fortunately the Chernobyl reactor was an old and unsafe design, only one other reactor in the world was built the same way. It was right here in Berkeley, a research reactor built on campus in the fifties. It was sagely decided to quietly shut it down after Chernobyl; while it couldn t have had an accident on the scale of Chernobyl, the locals were a little concerned anyhow. In fact it was a block away from my favourite burrito place, yikes.
(The above image was released into the public domain by its author. Credit: Jason Minshull.)