
Chernobyl Fungus Feeds On Radiation (2007) - skennedy
http://www.scienceagogo.com/news/20070422222547data_trunc_sys.shtml
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ChuckMcM
So following up later papers that cite the original [1] doesn't seem like this
has gone very far. A number of papers collecting extremofile exemplars, and a
few thinking about energy sources. But nothing on 'space food', 'radioactive
remediation', or analysis of the energy source in humans. Sigh.

[1]
[http://scholar.google.com/scholar?cites=14704617567455474393...](http://scholar.google.com/scholar?cites=14704617567455474393&as_sdt=2005&sciodt=0,5&hl=en)

~~~
mileszim
The problem is that the active molecule itself has a complex structure, and it
is very hard to get a high-resolution image of even one of its structures
(melanin can be folded in lots of ways). There's some potential for better
imaging with fairly recent discoveries in partial-wavelength resolution
microscopy using weak-measurement, but it's still a new technology. Melanin's
mechanism for absorbing ionizing radiation, if understood, will definitely
open up major applications for a perfected, synthesized solution.

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civilian
So, radiation is a big risk factor in sending astronauts to Mars and around
the solar system.

What if we could genetically engineer ourselves to use this melanin pathway
for ourselves?

We wouldn't use energy from radiation in the fungi-melanin pathway (although
we could), but it could be good to make our bodies recognize that a radiation
storm is happening and that could trigger biochemical changes in our bodies.
Either to become more radiation proof (hide yo' DNA in chromatin) or take some
radiation-resilient actions (heavily increase the reproduction of cells in our
gut lining).

This isn't a very realistic idea, just a sci-fi thing. We have a hundred years
of ethics and technology to accomplish before this would be realistic.

~~~
jlgreco
From what I understand of this, the fungus basically "eats" radiation in the
sense that plants eat sunlight, but that only prevents the radiation from
damaging the fungus to the extent that the radiation hits the melanin instead
of hitting the DNA or whatever.

So if you made a human that did this, you would have a human that could
refrain from eating much food for energy and instead choose to hang out in a
nuclear reactor _(they would still need to eat to take in nutrients, but would
need fewer calories I guess?)_ ...but they'd _also_ still get radiation
poisoning / cancer / etc.

Also, it isn't clear to me how these could be used to "clean up" messes
anymore than sunbathers could clean up the sun. It seems they just absorb
gamma rays, but nothing about them doing that should make that material decay
faster... Maybe the idea is that they intake the radioactive particles and
consolidate them so that cleanup then entails finding the fungus (which is
presumably easier to visually locate) and scooping it all up? Maybe you could
engineer the fungus to also bioluminescence strongly to aid in this.

~~~
fragsworth
Likelihood of cancer may be related to the general chance of reproductive
mutation, and the chance of reproductive mutation is also likely to be
something that changes through evolution.

If you have a species in a high-radiation environment, is it not possible that
it evolves to have fewer reproductive mutations in general - and therefore
lower chance of cancer?

~~~
jlgreco
Yes, I think it makes sense that certain arrangements of DNA would be less
susceptible to going cancerous than others. In one strand you might have a
possible '1 bit flip' _(I 'm not a biologist in the slightest)_ change that
would turn the routine into _" while(1) {fork();}"_, but perhaps in another
functionally equivalent strand you would need to flip 2 or 3 bits to get the
same effect.

So basically you want to select for DNA that has a large (DNA equivalent of)
Levenshtein distance to cancerous DNA. Perhaps that is something that you
could even deliberately engineer (though I don't think a general _solution_ is
possible since determining if DNA is cancerous might be the halting problem?)

Maybe it would be easier to construct a strand of DNA that has the same effect
as another strand of DNA, but with more error-checking. Throw in a bunch of
asserts or something to send cells with DNA that fails the error checking into
suicide mode...

~~~
gizmo686
In practice, I suspect that we have numerous ways of dealing with mutations.
However, if I recall my high-school biology correctly, during DNA replication
there is error correction. My guess would be that evolution would tend to
regulate mutations rates through the efficiency of error correction mechanisms
(and the accuracy of the primary duplication mechanism) more so than a meta-
evolution in the structure of DNA. Having said that, it is reasonable that
there would be evolutionary pressure to have DNA that requires more mutations
before becoming dangerous.

Responding to the content of your post. DNA is not executable code as much as
data. The 'primary' purpose of DNA is to provide the blueprints for proteins.
DNA sequences can be thought of in by grouping the base pairs in 3 called
codons (this grouping is not reflected in the molecular structure). The
beginning and end of a gene are marked by "start" and "stop" codons, which are
just a specific DNA subsequence. Conceptually, a gene is converted into a
protein by replacing each codon with its corresponding ammino acid (based on a
lookup table) [1]. The function of a gene is determined by the chemical
properties of the resulting protein.

As it turns out, there are parts of DNA that do not code for proteins, yet
still have significant effect. However, I am not aware of any evidence of a
naturally occurring use of DNA that resembles executable code.

[1][http://www.biogem.org/codon.jpg](http://www.biogem.org/codon.jpg)

~~~
jlgreco
I suppose what I am suggesting is something along the lines of littering the
DNA with _lots_ more "stuff that does nothing" that has a very small edit
distance from _" encodes the creation of a protein that kills the cell."_

So while you might normally have:

    
    
      ... ACGATTACGATACG ....
      ---|--------------|---
           |
           useful protein
    

You would now have:

    
    
      ... ACGATTACGATACG TACC TACC TACC TACC TACC TACC TACC TACC TACC ...
      ---|--------------|----|----|----|----|----|----|----|----|----|---
           |                |
           useful protein   pointless proteins
    

The trick with the TACC being that perhaps TAAC, AACC, and TAGC all, rather
than encoding a pointless protein, each encode a protein that will kill the
cell. Any random damage to TACC will have a high chance of producing a
sequence that will be deadly to the cell.

So each time you get whacked by a gamma ray, you spin a die and see what it
hits. Maybe it hits a naturally occurring sequence like _' ACGATTACGATACG'_
and maybe you get cancer. Or maybe it hits one of those artificially inserted
_TACC_ segments that is designed to _usually_ break in such a way that the
cell is killed. Add more and more TACC segments and you become less and less
efficient, but the odds get stacked more in your favor the more you add.

It would kind of be the "electric fence" approach to arresting unintended
behavior
([http://en.wikipedia.org/wiki/Electric_Fence](http://en.wikipedia.org/wiki/Electric_Fence)).

I suspect actually pulling this off isn't something that is doable in the
foreseeable future, since it would require being able to make strong
statements of the nature _" This segment of DNA should have no effect"_, and
similar, but it makes sense in my head at least ;)

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mileszim
This is a very cool fungus, I'm glad this was posted! The trickery of its
survival comes from its use of melanin, specifically pheomelanin. Basically
what happens is when ionizing radiation strikes pheomelanin, an incident
electron is generated because of something known as the Compton effect (think
photoelectric effect but at really high energy). Somehow, pheomelanin is able
to strip down the energy of the electron until it is no longer capable of
acting as a free radical and destroying surrounding matter. Unfortunately,
that mechanism is still unknown, hopefully with the development of higher
resolution microscopes we can get a more thorough understanding of the
molecular structure.

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ben1040
This reminds me of the fungus you see growing on the sides of distillery
facilities (if you ever go through bourbon country in Kentucky, all the whisky
aging warehouses are covered in the stuff). Instead of radiation, they thrive
on ethanol.

[http://en.wikipedia.org/wiki/Baudoinia_compniacensis](http://en.wikipedia.org/wiki/Baudoinia_compniacensis)

~~~
sp332
If you're bored and want a story about it:
[http://www.wired.com/magazine/2011/05/ff_angelsshare/all/1](http://www.wired.com/magazine/2011/05/ff_angelsshare/all/1)

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ealloc
Interesting. Only 2 photosynthetic molecules are known so far in all branches
of life, chlorophyll and rhodopsin, so the existence of another photosynthetic
pathway is pretty surprising! I hope it's not another case of hype followed by
debunking like for "arsenic dna" or "antideluvian dna".

The study seems to be done properly though, and hints at a possible mechanism,
so maybe. I'd need a couple follow up studies of the mechanism to be
convinced!

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Zikes
(2007)

Very interesting, though. Just not very new.

~~~
vanderZwan
Yes, I remembered hearing about it back then. But this does make me wonder if
anything new has been found out about how it works. A quick wikipedia/google
scholar suggests it hasn't, sadly.

[http://en.wikipedia.org/wiki/Radiotrophic_fungus](http://en.wikipedia.org/wiki/Radiotrophic_fungus)

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kevinchen
This is almost out of a Michael Crichton book. So close.
[http://en.m.wikipedia.org/wiki/The_Andromeda_Strain](http://en.m.wikipedia.org/wiki/The_Andromeda_Strain)

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xacaxulu
I hope this could be cultivated and embedded around sites in Japan.

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TrainedMonkey
I am pretty sure I've heard something about Japanese wanting to try radiation
"eating" fungi at Chernobyl ago in order to decontaminate the area almost a
decade ago.

~~~
alephnil
The fungi can't break down radiation, no known method can do that(1), and
probably not even collect it. The amount of radioactivity is unchanged
regardless of the presence of these fungi. They only use the radiation that is
there as an energy source.

(1) Bombarding with neutrons or high energy charged particles may change the
amount of radioactivity. Also, positron-emitting nucleotides can have slightly
faster halflife at very low temperatures. None of these methods are available
for the fungi.

~~~
mileszim
Melanin has about a 30% absorption rate of ionizing radiation in the gamma
spectrum, and remains stable (not oxidized in the traditional rate) while
producing a current. The fungus is able to produce an acidic fuel source from
the current that it feeds off of. The fungus is definitely breaking down
radiation, incredibly, but it's mechanism is very poorly understood.

~~~
gus_massa
The fungus is (apparently) absorbing the radiation and using it as an energy
source. But it is _not_ making the radioactive atoms decay faster. So the time
we have to wait until the area is safe and has a low radioactivity level
doesn’t change.

~~~
Tharkun
True, but a layer of fungus would presumably act as an insulator, as it's
absorbing part of the radiation? Perhaps it would be easier/cheaper/prettier
to cover the sarcophagus in the fungus than in more concrete? Depending, of
course, on a) how much it actually absorbs and b) how thick you can pile the
stuff?

~~~
mbq
Nah, when gamma photon is absorbed it doesn't matter whether its energy will
be used for fungal metabolism or converted to heat right away. And in case of
gamma absorption rate mostly depends on mass density, so fungi will be likely
as good as water. Concrete not only absorbs more radiation for the same
thickness but is far more stable than anything alive.

~~~
TheZenPsycho
what about the toxicity of the water as a result of being exposed to
radiation, versus the toxicity of the fungi?

~~~
yongjik
I'm not a nuclear scientist, but I can't think of any way pure water may
become "toxic" due to exposure to radiation (instead of dissolving radioactive
materials, which would definitely be a problem). Maybe excessive neutron
radiation could build up tritium, but that already sounds like a stretch.
(Most radioactive elements don't emit neutron spontaneously.)

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plu420
[http://fukushima-diary.com/2013/06/black-
substance-170000-cp...](http://fukushima-diary.com/2013/06/black-
substance-170000-cpm-possibly-130000140000-cpm-from-%CE%B2/?/)

A black organism that bioaccumulates radionuclides has being known of in Japan
for a while.

I wouldn't go so far as to say this is a good or bad thing before we've
studied this radioactive monster; considering how very hot it is I'll leave
the studying to up someone else...

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GuerraEarth
Funghi absorb radionuclides strongly. The reindeer and other grazers who eat
lichen, etc. are all highly contaminated now. Look up radiotrophic funghi.

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DonGateley
"Just as the pigment chlorophyll converts sunlight into chemical energy that
allows green plants to live and grow, our research suggests that melanin can
use a different portion of the electromagnetic spectrum - ionizing radiation -
to benefit the fungi containing it,"

One problem with that. Ionizing radiation is not on the electromagnetic
spectrum. It's particles with rest mass.

~~~
TheEzEzz
According to the infallible Wikipedia ionizing radiation can refer to either
electromagnetic radiation or massive particles.

[http://en.wikipedia.org/wiki/Ionizing_radiation](http://en.wikipedia.org/wiki/Ionizing_radiation)

~~~
DonGateley
I should have looked that up, huh? :-)

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punkghetto
Would be awesome if this could be developed as a method to decontaminate or
stabilize areas affected by nuclear accidents.

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evolve2k
So the fungi essentially absorbing some of the radiation and transforming it.

Does this mean that this is positively affecting the radioactive halife of the
area because the fungi are essentially living off the excesses radiation
present and will help contribute to reduce the radiation levels over time?

~~~
VLM
No. Just like shining a flashlight on a traditional plant doesn't make the
batteries wear out any quicker or slower.

However, every gamma it adsorbs, is, well, adsorbed. Its probably not a very
good shield compared to sandwiches of iron and water, but its probably better
than empty air. Perhaps in the future you could grow a reactor core using a
tree. This would make a good minecraft mod.

If it were very aggressive about growth, maybe it would physically block
rainwater from hitting the contaminants and running off contaminating
downstream. Rainwater hitting harmless fungus and flowing away would help, a
little.

~~~
evolve2k
I can't quite tell if you are trolling me, but I'll assume for the best as I
am truly curious on this.

To take your analogy the torch will loose battery at the same rate but with
the plants leaves receiving more light it would be less light that goes in the
face of the person standing behind the plant. Do the plants absorbing
radiation lead to less radiation being around to be absorbed by humans and
animals instead? Maybe I am fundamentally misunderstanding something here.

~~~
VLM
radiation adsorption occurs at an atomic level too fast for anything chemical
to happen WRT the adsorption, so a peculiar arrangement of atoms can't have
any effect on overall shielding levels other than bulk density (like how much
"stuff per inch" depends on what stuff is). The hack of the system is the very
peculiar arrangement of atoms for this specific fungi can make productive use
of the gamma energy which most living things can't do. From a nuclear
standpoint long after the gamma is ancient history the chemistry can get
started (theres a big timescale mismatch). A plain old mushroom or any ole
biomass will block the gammas as effectively as this one. Of course a plain
old mushroom or biomass can't live in that location; nothing to eat.

It would be like building a firewall that acts like any other firewall, except
under DDOS conditions it uses a whole network of diodes and stuff to store up
the electrical energy of each attack packet. This doesn't work with routers
because they take maybe "hundreds of watts" to run but the received laser
power might only be "hundredths of watts". For a fungi that grows slow enough
and has no competition in its niche, gammas are apparently enough.

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andrelaszlo
Older news: "Exotic Underground Bacteria Thrive On Radiation Rather Than
Sunlight"

[http://www.scienceagogo.com/news/20060919234956data_trunc_sy...](http://www.scienceagogo.com/news/20060919234956data_trunc_sys.shtml)

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everyone
Amazing, I guess its easy forget life on earth is billions of years old and
extends deep into the planets crust. It has adapted to some completely
different environments than what we normally associate with life.

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Houshalter
This isn't really "new" but still pretty interesting.

EDIT: Title changed.

