Devourer of Radiation

I'm surprised that I had forgotten about this story until I caught up on my article reading list this afternoon.

Ionizing Radiation...Enhances the Growth of Fungi - PL0S 0ne

(this open access journal is part of a audacious federal project worthy of its own post...coming soon)

But anyway, here's the punchline:

Some fungi may be capable of consuming radiation.

The story:

Melanin (the pigment in your skin that protects you from the sun) is an amorphous aromatic polymer that plays many different roles in many different organisms. Fungi use melanin both as a shield against the environment and a weapon against hosts (another story I intend to follow up on). Melanin has been well documented to shield cells from the damaging energy of electromagnetic radiation, such as UV light, by both absorbing and scattering photons and electrons. The authors of this paper set out on this topic with the hope of characterizing the physico-chemical changes that take place when melanin molecules intercept light.

In the process of their experimentation, they noticed that three species of melanized fungi grew significantly more (by four measures) when they were irradiated than when they were not. They also observed that melanin was capable of increasing the redox reaction of NADH and ferricyanide when irradiated (by passing electrons between the two chemicals).

Towards the end, the authors review previous indirect evidence for the idea that radiation is beneficial for the growth of some melanized fungi. One species has been found to be radiotropic - preferentially growing towards sources of radiation. This organism, Cryptococcus cladosporiodes, has become very common in the region surrounding Chernobyl since the meltdown. In both lab and field studies, other species of melanized fungi have been found to grow towards radionuclide-cotaminated soil particles, which were then apparently consumed.

So it may be possible that some melanized fungi are able to live off radiation (both electromagnetic and from decaying radioactive particles), I presume, by capturing photons/electrons like chlorophyll pigments and passing them down the electron transport chain.

Maybe we can turn all the nuclear waste holding tanks around the country into fungal fermenters instead of fighting the NIMBY monster of Yucca Mountain.