Melanized Fungus Grows Faster Exposed to 500 Times Normal Radiation Levels

Melanized fungus grows well in the Chernobyl reactor and in high radiation of space stations. The fungus can prosper when radiation is 500 times background levels. The Melanin absorbs all types of electromagnetic radiation and could be used for energy transduction and radiation shielding.

Melanized fungal species in the Chernobyl reactor have enhanced growth when exposed to ionizing radiation. Fungi colonize space stations and adapt morphologically to extreme conditions. Radiation exposure causes upregulation of many key genes, and an inducible microhomology-mediated recombination pathway could be a potential mechanism of adaptive evolution in eukaryotes. The discovery of melanized organisms in high radiation environments, the space stations, Antarctic mountains, and in the reactor cooling water combined with phenomenon of ‘radiotropism’ raises the tantalizing possibility that melanins have functions analogous to other energy harvesting pigments such as chlorophylls.

Melanized W. dermatitidis and C. neoformans cells exposed to ionizing radiation approximately 500 times higher than background grew significantly faster as indicated by higher CFUs, more dry weight biomass and 3-fold greater incorporation of 14C-acetate than non-irradiated melanized cells or irradiated albino mutants. In addition, radiation enhanced the growth of melanized C. sphaerospermum cells under limited nutrients conditions. The observations that melanized fungal cells manifested increased growth relative to non-melanized cells after exposure to ionizing radiation raised the intriguing possibility that melanin can function in energy capture and utilization.

Melanin pigments are found in all biological kingdoms, suggesting that these compounds are ancient molecules that emerged early in the course of evolution. Melanins are complex polymers with a variety of properties that can be made enzymatically from relatively simple precursors. A remarkable aspect of melanins is their ability to absorb all types of electromagnetic radiation which endows them with the capacity for both energy transduction and shielding. The findings of melanized organisms in high radiation environments such as the damaged reactor at Chernobyl, the space station, Antarctic mountains, and reactor cooling water combined with phenomenon of ‘radiotropism’ raises the tantalizing possibility that melanins have functions analogous to other energy harvesting pigments such as chlorophylls.

8 thoughts on “Melanized Fungus Grows Faster Exposed to 500 Times Normal Radiation Levels”

  1. Because, “Hey, Bob! Can you go check on the irradiated melanized fungus?” always turns out so well in science fiction movies.

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  2. Actually, in a recent post where Goat Guy and I started looking at neutron star supernovas and heavy metals (https://www.nextbigfuture.com/2020/01/second-collision-of-neutron-stars-detected.html), it was mentioned that early Earth must have been fairly toasty with radiation from nuclear decay back when life was already a going thing.

    Now this. I went to look at the source article referred to and found:

    Life emerged on Earth at a time when there was much higher background radiation and early life forms must have considerable radiation resistance. Although current background radiation levels are much lower than on the early Earth, earthly life still exists in a field of radiation. For example, 90% of the annual radiation dose for a person living in the US comes from natural sources such as cosmic radiation and radioactive rocks.

    and:

    Large quantities of highly melanized fungal spores have been found in early Cretaceous period deposits when many species of animals and plants died out. This period coincides with Earth’s crossing the “magnetic zero” resulting in the loss of its “shield” against cosmic radiation.

    As far as being ooh, scary, I don’t think so, for a lot of reasons. It does raise the bar a bit on where we can hope to find primitive life, though.

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  3. Putting aside the relevance of melanin (which as noted, is unlikely to help much against much else besides UV), I can imagine radiolysis driving some useful reactions that would be difficult without it. But it’s pretty random, so it would also cause a bunch of problems.

    edit: On 2nd thought, some molecules (perhaps adapted melanin?) could be better at stopping beta radiation, and alphas are pretty easy to stop, as long as they’re not too energetic. Gammas probably don’t interact enough to be much of an issue for a single-cell organism below some intensity threshold. And some dense clump of material might act as a sacrificial layer to stop some neutrons, maybe? Probably water would be more effective at that, but it’s not a structural material.

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  4. People like Hargraves really reaching for an example where dose is better than benign.

    Paraphrasing and interpreting what you said in the first comment, melanin is effective in managing UV, not gammas from fission/activation products.

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  5. Yes, a combination of scare tactic about mutant organisms, a quest for research dollars, and pie in the sky nonsense. With just a little hint of real science there somewhere.

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  6. I highly doubt this can shield remotely as well as the usual materials. You need atomic nuclei to get in the way of radiation to obstruct it. Though the prospect of highly ionizing radiation energy utilization is interesting.

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  7. If you are up on your Earth Chronicles, you would be aware of the planet Nibiru. As you would be aware, Nibiru has an orbit that takes it far outside our solar system and the planet is also highly radioactive. I suspect that radiation fulfills the same function as light on our planet.

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