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Radiotrophic fungus (wikipedia.org)
262 points by zerogvt on July 3, 2019 | hide | past | favorite | 63 comments

> Radiotrophic fungi were discovered in 1991 growing inside and around the Chernobyl Nuclear Power Plant.[1]

The original study is open access and is worth reading. Here's an interesting little review:

> The literature already contains some indirect evidence for the notion that radiation can enhance the growth of melanized microorganisms. For example, the melanotic fungus C. cladosporioides manifests radiotropism by growing in the direction of radioactive particles and this organism has become widely distributed in the areas surrounding Chernobyl since the nuclear accident in 1986 [7]. Both in the laboratory and in the field several other species of melanized fungi grew towards soil particles contaminated with different radionuclides, gradually engulfing and destroying those particles [35], [36]. In addition, there are recent reports that certain life forms can utilize non-conventional forms of energy - microbes in geothermal vents at the bottom of the ocean can harvest thermal radiation as an energy source [37] while some microorganisms living in mines exploit energy from radiolysis of water [38]. On the basis of these precedents and the results of this study we cautiously suggest that the ability of melanin to capture electromagnetic radiation combined with its remarkable oxidation-reduction properties may confer upon melanotic organisms the ability to harness radiation for metabolic energy. The enhanced growth of melanotic fungi in conditions of radiation fluxes suggests the need for additional investigation to ascertain the mechanism for this effect.


In particular the part about growing towards contaminated particles, "engulfing and destroying" them, seems like a finding with enormous practical potential.

No known biological process can "destroy" a radioactive isotope...

I wonder what they mean... Perhaps they simply mean "break up"

I guess the papers they cite are in Russian, so maybe someone else can dig into it more, but at least they link to abstracts in English [1,2] which say

> Two ways of radioactive particles destruction by C. cladosporioides were established, one of them is a direct way by fungal overgrowth of hot particles and the second one an indirect way only by fungal metabolites.

> It has been found out for the first time that Cladosporium cladosporioides and Penicillium roseo-purpureum are able actively overgrow "hot" particles whose radioactivity did not exceed 3.1-1.0(-7) Ci by gamma-spectrum and to destroy them 50-150 days later.

So it seems that the fungus forms a layer around the particle?

[1] https://europepmc.org/abstract/med/12664550 [2] https://europepmc.org/abstract/med/1753889

With "destroy" you mean turning something radio-active in something non-radio-active?

That would mean the fungus is capable of nuclear transmutation.

I’d highly doubt that.

I too was fascinated by that statement. How does it destroy them? Is it extracting energy faster than would be let off in vacuum? Or is it an encapsulation?

I presume that the fungi grow toward the source of radioactivity until they engulf it, and it is not destroyed, but instead segregated and more easily separable from the environment by bio-accumulation.

I.e. if you seed radioactive soil with radiotrophic fungi, wait a few years, and then mechanically separate fungus from soil particles, the separated soil would be less radioactive than it had been previously.

Presumably, though, other surrounding places will be more radioactive than before?

The fungus itself will be more radioactive than background.

I don't believe neutron activation is significant anywhere on Earth outside the containment of a fission reactor, power research facilities, or nuclear bomb tests. So mostly, places slowly become less radioactive over time unless you get radioactive particulates from one of the aforementioned sources, or from a natural concentration, and release them into the environment somewhere.

Bio-accumulation can occur, such as the naturally radioactive potassium in a banana, but that's just shifting around the radioactive materials already present in the environment.

Wherever you dump the fungus, or the ashes of the fungus, will be more radioactive than before. So a bio-remediation plan would likely grow fungus, separate most of it from the soil, and allow the remaining fraction to regrow, repeating as necessary. The separated fungus would be burned, and any radioactive fractions removed from the exhaust gases and dissolved in liquid or crystallized somehow. The ash would be vitrified into glass pellets.

And then it'd probably still be less radioactive than an asphalt parking lot. But okay, seal it all up inside a drum and forget about it for 10000 years anyway.

Circulate it within a semi-closed system full of funghi. A reverse breeder reactor - a condensing decayer. Vent excess material to radiology equipment.

Then sprinkle in some high-melanin humans, to grow your very own super-mutant facility personel. Perhaps also feed them mushrooms, to speed up the adaptation process.

The next generation will be... autotrophic?

You must have never went to a place with active radon gas venting... Or to the mountains.

Of course significant is in eye of the beholder, but those places do exceed typical background doses a lot.

Uranium -> thorium -> radium -> radon -> ... -> lead is a natural decay chain that does not typically activate other atoms to become unstable, so the decay energy between uranium and lead represents all the radioactivity there will ever be from that uranium. You can't predict exactly when it will be released, and because radon is a gas, you can't as easily predict where it will be released, but once you get to stable lead, it's done.

If you tack up a slab of any stable nucleus higher than iron on the nuclear binding energy curve to the inside walls of a neutron chain-reaction reactor, you can probably get it to absorb neutrons of the appropriate speed and become unstable, promising future radioactivity with an amount of energy between its current state and whatever its final decay product may be. That may be less total energy than the difference between uranium and lead, but it probably runs faster from start to finish than billions of years, and is probably more energy than the absorbed neutron.

So aside from natural reactors, which mostly shut down a long time ago, the only increases in radioactive potential are going to be from human-built reactors. The radon is just moving primordial radioactive potential from where the radium is, which is also where the uranium or thorium is, to wherever heavier-than-air gases can accumulate. If you remove the radium, you stop that. If you encapsulate the radium in a glass that traps gas, you stop that.

Mostly, we don't bother trying to remove trace amounts of uranium and other radioactive isotopes from mineral resources, but if a fungus could do it cheaply, it could make coal ash less dangerous to process and store.

Degrade would be a better word. In other words, break down organic material into simpler molecules and use them as a source of respiration, releasing radioactive carbon as CO2 and, potentially, radioactive isotopes as compounds that are gaseous or water soluble. This is the normal action of fungi.

The particles in question are likely dust specks, and destroying them probably just means breaking them up into smaller pieces.

If you're interested in funghi, I recommend Joe Rogans podcast with Paul Stamets, funghi seem to be able to do many things: https://www.youtube.com/watch?v=mPqWstVnRjQ

Ammusingly, Paul Stamets is the name of a scientist in the newest star trek series. He is an astro-mycologist and apparently they named him for this real scientist.

Paul Stamets is a fascinating person. You're right, the Star Trek character is named after him [0]. I remember hearing, perhaps in the Joe Rogan podcast, that he consulted for the show. He has a brilliant TED talk on the world-changing potential of fungi research [1].

[0] https://www.cbc.ca/news/canada/british-columbia/paul-stamets... [1] https://www.youtube.com/watch?v=XI5frPV58tY

He's also a primary "character" in Michael Pollan's book "How To Change Your Mind", on psychadelic mushrooms and LSD (which I'm about halfway through). Pollan has a pretty funny relationship with him -- almost like "frenemies".

the character is named after him.

The comment you are responding to says that.

So long as we're correcting people, no. The comment in question says "apparently" the character was named after him. Someone replied that was in fact the case. Then you came along and shamed the person for confirming it.

for what is worth the parent comment I responded to was: "Ammusingly, Paul Stamets is the name of a scientist in the newest star trek series." The clarification was added afterwards, but who cares. if people want to downvote me, go ahead :)

I listened to this while preparing for and sitting in a trans-atlantic flight and I loved the whole thing. Paul Stamets verges on cuckoo and it only seems to add to his charm!

Incredible podcast. Super interesting to see somebody so completely soaked into a single topic.

Stamets' book, Mycelium Running: How Mushrooms Can Help Save the World [0] is very good, and his enthusiasm is definitely contagious. I will check out the podcast, thought tbh Joe Rogan is pretty hit or miss for me.

[0] https://www.amazon.com/Mycelium-Running-Mushrooms-Help-World...

He seems like a fun guy.

How fast do these fungi grow?

Might they be a future food source? Radioactive materials could be coated in an inert material and made into pellets which would be easy to filter from the final resulting food.

Meanwhile we use can use gamma radiation only by converting first to heat.


Most of our "energy generation" is still based on 19th century physics

Sure heating stuff and turning water into steam is easy, but it might not be the most efficient way of turning some sources into energy

This has always bothered me. To think that we can induce nuclear fission, but then can't actually use the generated energy without boiling water and using it to turn a turbine!

Sometimes we just stumble onto a near ideal solution early. A chain on a cog for a bike drive for instance. People keep trying other things but they are all less efficient.

This is more efficient:


It's a shaft with a weird gear at the end. The gear teeth spin on ball bearings.

According to whom? The manufacturer?

This company is known for selling snake oil products to amateur cyclists.

When I see this on Tour de France I’ll believe it.

competitive cycling doesn't let racers use whatever setup they want for their bikes.

if something is too good, like the really aerodynamic handlebars, they won't be allowed

Aero is quite regulated. So you can't play with wheel size, or various non-traditional bike designs. But other things seem like fair game, tweaks to geometry, different bearing technologies, new bearing races, electric shifting, disc brakes, etc.

The spirit of racing is that the race should be won largely by the best bicyclist, not the best bicycle. I'd expect a more efficient transmission would certainly be considered.

Disc brakes were also banned for pretty long.

Right, but aren't now. Progress is being made, fortunately mountain bikers (and their organizations) are much more open to progress.

Or at least tested by a well known 3rd party. There's been quite a bit of research on bicycle efficiency, if this worked I'd expect it to be big news in various bike research related circles.

For now I'm quite dubious, especially the claim that it gets more efficient the faster you go.

for pedalling speeds, my understanding is that a belt drive is more efficient than a chain

Not sure exactly what you mean. But every test I've seen shows the traditional chain is more efficient than a belt. The belt justifications I've seen are less maintenance, cleaner (no oil on clothes), and quieter. Never seen anyone claim it's more efficient.

Thus almost all bikes and nearly all motorcycles use chains, the higher the performance the more likely they are to use chains. However electric bikes (where efficiency isn't as important) or harley motorcycles sometimes use belts. As do folding bikes where you might come in contact with the belt.

But racing bikes or motorcycles are pretty much always chains.

Yea, but fission is just a fancy way to generate heat. Rest is basically the same. Turn it into mechanical energy, and then into electric by moving magnets vs coils.

The only other ways of generating electricity we use are different way of getting mechanical power, like wind or water, and solar cells. The latter is the only one on top of my head that's not mechanical.

Maybe making electrons move sensibly isn't that easy. Heat seems easy.

batteries and fuel cells, arguably the same thing. not mechanical or a heat engine.

Ultimately, we have only improved upon our two earliest tools: fire and pointy sticks.

I know nothing about this but just did a little reading. It seems some direct nuclear to electricity methods are 90% efficient.


PIDEC sounds like it works well with conventional IV gen reactors, achieving an extra 40% efficiency. ICC (a kind of DEC) seems suited to fusion and can exceed 90% efficiency.

I suspect the problem is that we've been building steam engines for a very long time, and have become very good at it. We'd be starting at zero, from an engineering standpoint, for PIDEC and ICC. It's a worthwhile task, but it would be billions laid down for something that has never been done at scale before (read: the government would have to fund the experimental reactor).

Actually in a lot of cases turning heat into steam is MORE efficient than alternatives. Direct thermoelectric conversion has an efficiency of 5% to 10%, whereas multistage steam turbines are 36% - 42% efficient.

This is also the reason why kilopower (a replacement for RTGs) is looking to replace thermoelectric conversion with sterling engines that are 30% to 34% efficient.

Unless you avoid producing heat (in the thermodynamic sense), the Carnot efficiency is a hard upper limit. A fancy steampunk apparatus to harness heat near the Carnot limit is still optimal.

Improvements come from running hotter or from avoiding producing heat in the first place. Some newer nuclear reactor designs output their heat at very high temperature, and devices like fuel cells and direct capture of beta particles can, in principle, exceed the Carnot efficiency available from using the fuel to heat something.

I’m amazed by it. Using a low cost molecule’s phase change, electromagnetic material stimulates electrons in high temperature conductive material.

There isn't any other reasonable way.

Direct thermoelectric conversion usually peaks in at about 10% effiency on the top end.

Steam Turbines can hammer down 40% and more easily.

Well, that’s how these organisms do it as well.

I wonder if there's any possibility of genetically engineering the fungi and using them to extract more energy from contaminated areas and nuclear waste as a form of biofuel. That would be quite an interesting way to use nuclear waste.

If someone does this, please name your gamma radiation absorbing fungi "The Hulk". :)

...with the corresponding scientific name would be "Brucea Banneriolus".

On a related note, I wanted to mention "mycoremediation", a "fungi-based technology to decontaminate the environment" [0].

In particular, I learned in the wake of the Fukushima incident that the mycologist Paul Stamets suggests an unusual plan to remove radioactive and other pollutants from soil/land. [1]

[0] https://en.wikipedia.org/wiki/Mycoremediation

[1] https://www.permaculture.co.uk/articles/using-fungi-remediat...

Given the fact there's hardly any such radiation in the wild, does that mean they evolved that ability just within a few decades? If so, that would be quite astonishing as it seems pretty different from other biochemical mechanisms (e.g. photosynthesis).

Radon is an issue many places. It comes from naturally occurring thorium and uranium in rock, especially granite.

I imagine fungi and bacteria might have evolved to be able to utilize the radioactive energy in areas with relatively high concentration.

There is background radiation, but natural nuclear fission reactor can exist too...


Based on how we humans use melanin, I would believe that this is a case of having these environmental-stress-reduction "tools" basically already in play (to deal with UV, free radicals, background radiation, etc.), then capitalizing on their functionality when a new source of stress (ionizing radiation) enters their world.

Not to suggest that the melanin with these particular fungi wasn't a wee bit unique to make it better at dealing with converting ionizing radiation usefully, or that natural selection hasn't taken place to improve the existing melanin for even better utilization of this abundant, high-energy source! I just don't think that the fungi created this from scratch after the exposure began.

There is another example of this occuring, linked from that Wikipedia page:


Humans did not invest radioactive decay. We merely discovered it.

Of course, but the radiation caused by artificial reactors (and their leftovers) is magnitudes higher than anything in the wild.

I'm surprised no one here has mentioned the post-apocalyptic platformer, Mushroom 11. Radiotrophic fungus lends a lot of credence to a game where you guide a mycelial glob through the remains of a nuked landscape.

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