
Caterpillar found to eat shopping bags, suggesting solution to plastic pollution - fh973
https://phys.org/news/2017-04-caterpillar-bags-biodegradable-solution-plastic.html
======
sosuke
_" To confirm it wasn't just the chewing mechanism of the caterpillars
degrading the plastic, the team mashed up some of the worms and smeared them
on polyethylene bags, with similar results."_

A disturbing but effective way to test the hypothesis.

~~~
leoreeves
Yeah, pretty horrible.

~~~
aw3c2
Ever killed a fly because it annoyed you? This is not much different. In fact,
this was done for science.

~~~
sillysaurus3
I try not to kill flies, no. The only exception is for multiple flies that
won't go away. Ditto for ants.

It's a bit strange that violence toward insects is fine, but violence towards
dogs is not. Ever killed a dog because it annoyed you?

That said, doing it for science at least has a justification.

~~~
mikeash
It's because insects have such a primitive nervous system that we don't see
them as being aware in the same way that a dog is.

You draw the line _somewhere_ , right? Drawing the line at a certain
complexity of the nervous system is more sensible than drawing it at "animals"
in general, IMO.

~~~
matz1
I draw the line at Human and Not Human.

~~~
PerfectElement
Any objective justification for that or just your own bias?

~~~
labdsf
Just as mirimir said, it is biological norm to draw line between your own kind
and everyone else. For example, both dogs and cats don't kill each other, but
dog can easily kill a cat.

~~~
b6
Both dogs and cats do kill each other. It is not uncommon at all.

~~~
3131s
Yep, cats fight brutally all the time. My wife's old cat was a fighter and had
the scars to prove it. No doubt he had killed many cats, and then he
eventually succumbed to an infection from a nasty neck wound acquired in a
fight.

~~~
0xFFC
Ha ha ha, he was quite champion

------
Clanan
"A chance discovery occurred when one of the scientific team, Federica
Bertocchini, an amateur beekeeper, was removing the parasitic pests from the
honeycombs in her hives. The worms were temporarily kept in a typical plastic
shopping bag that became riddled with holes."

What a great accident.

~~~
jacquesm
The history of science is full of such accidents, the discovery Penicillin
being one of the most famous.

[http://www.kidsdiscover.com/quick-reads/penicillin-found-
fun...](http://www.kidsdiscover.com/quick-reads/penicillin-found-functional-
fungus/)

~~~
smueller1234
Maybe the antithesis to the discovery of antibiotics is the mostly accidental
discovery of Tabun: "In January 1937, Schrader observed the effects of nerve
agents on human beings first-hand when a drop of tabun spilled onto a lab
bench." (Wikipedia)

I think that one might stand out somewhat since I'd expect most accidental
advances to be helpful to humanity. Or maybe I'm just an optimist. :)

~~~
jacquesm
Scientists that voluntarily work to bring such stuff in the world are amongst
the people I least respect. It's one thing to be dumb, quite another to be
extraordinarily gifted and to use that gift to do something which has no
upside at all and plenty of downside. Exposing them to their own creations
would be poetic justice.

~~~
mynameisvlad
I mean, it's not like they're going into it knowing they're about to create a
nerve agent. It even says in the history for Tabun on Wikipedia [0] that it
was initially meant to be an insecticide. Sarin was similarly created as a way
to find stronger pesticides, and IIRC so was Zyklon B, used in the holocaust.

So some of these scientists may not have known what their creations were going
to be used for.

[0]:
[https://en.wikipedia.org/wiki/Tabun_(nerve_agent)](https://en.wikipedia.org/wiki/Tabun_\(nerve_agent\))

~~~
jacquesm
After making a demonstration to the army and being set up with a lab by the
army and being asked specifically to weaponize your research (and fill
projectiles with it) I don't think there should be any 'we didn't know'
excuses.

It's pretty clear that even if insecticide was the beginning there was a
pretty clear point in time where it was obvious that this had nothing to do
with insects any longer.

~~~
mynameisvlad
And at that point what are they going to do? Say no?

Okay, then they'll get someone else to take your work and weaponize it. The
bulk of the work would have already been done by then, which is synthesizing
the chemical and showing its effects on people.

~~~
jacquesm
Principles are pointless if there is no price to pay.

By your reasoning you can excuse away any behavior. Which of course plenty of
scientists and other horrible people tried to do. And then there was the
collective amnesia epidemic of 1945.

~~~
mynameisvlad
And by your reasoning, you should get locked away the second your research can
get weaponized.

Shockingly, it's not a black and white world with many layers of gray in
between, which is what I was trying to show. That a lot of research can get
twisted for evil.

In your earlier post, you claimed there was "no upside". That's patently
false, since these started with the ideal of getting rid of pests more
efficiently. Yes, there's a point where it turns from this generic research to
weaponizing, but that might not be immediately obvious at the time, nor what
the repercussions might be 50 years later.

~~~
jacquesm
> And by your reasoning, you should get locked away the second your research
> can get weaponized.

No, the second people start weaponizing your research you have the option to
stop participating.

> Shockingly, it's not a black and white world with many layers of gray in
> between, which is what I was trying to show. That a lot of research can get
> twisted for evil.

Chemical weapons research is pure evil, I don't doubt that at all.

> In your earlier post, you claimed there was "no upside".

Yep.

> That's patently false, since these started with the ideal of getting rid of
> pests more efficiently. Yes, there's a point where it turns from this
> generic research to weaponizing, but that might not be immediately obvious
> at the time, nor what the repercussions might be 50 years later.

It was obvious within the lifetime of the scientists involved because _they_
were the ones to help weaponize it. And for that there are no excuses.

I really don't understand why you're twisting so much to come up with excuses
for these people here, their role and position in all this is pretty well
documented. If not for the Germans fear that allies would be able to retaliate
in kind that stuff would have been used.

This is one of the best documented era in the history of mankind, there are
people who deserve the benefit of the doubt but this particular group isn't
one of those.

~~~
TheSpiceIsLife
> No, the second people start weaponizing your research you have the option to
> stop participating.

I want to agree with this, but I'm not certain how I would act if I knew my
options where a) continue weaponisation research or b) get shot in the face.

~~~
semi-extrinsic
Crucially, option b) is actually "get shot in the face and then someone else
weaponises the research".

Making a principled stand is only useful when it stands a non-zero chance of
accomplishing something.

~~~
jacquesm
Or 'well shoot your wife and kids first if you don't cooperate'.

------
fenwick67
I am skeptical that any sort of bacteria/insect based plastic decomposition
project will address the problems with plastic waste.

The biggest problem with plastic is not with the products that make it into
the landfill, where bacteria could be used. The problem is with what happens
when they _don 't_ make it into a landfill, and they end up as basically
permanent pollutants in the water.

~~~
tuna-piano
I, for one, have never understood the problem with landfills. There's tons of
unused space left, and landfills take up a tiny fraction of that. Who cares if
we make a trash hill somewhere and styrofoam sits there for a million years?

~~~
mod
One of the better solutions, but nobody wants a landfill near them.

They're disgusting.

~~~
graphitezepp
Decent number of golf courses got built over landfills. Don't have to be
disgusting when we are done filling.

~~~
dmix
In a small town my parents live in they opened a park with a large hill,
originally landfill, and the kids tobaggon on it every year. One of the most
popular destinations in the town during winter. So agreed it's not all bad and
destructive.

------
ars
It makes sense that eventually things would eat plastic.

Lignin (wood) and cellulose are pretty tough to break down, but there are
things that eat them.

Plastic fundamentally (chemically) is made of the same stuff as wood, just in
a different arrangement of atoms, and releases energy when decomposed. So it
seems quite reasonable that there would be things that can eat it.

I think the plastic pollution we are seeing right now is a temporary thing -
soon enough there will a large enough population of plastic eaters that it
will no longer be a problem.

(We should avoid plastics that have chlorine in them though, except where
needed. PVC is the most common example of a plastic like this.)

~~~
Houshalter
These caterpillars didn't evolve to eat plastic as far as we know. Evolution
takes place on unimaginably slow timescales. It took tens of millions of years
for things to evolve to eat wood. Probably these caterpillars already happened
to produce a chemical that reacts with plastic. I wonder if they even get any
nutritional value from it.

That said, bacteria can evolve pretty fast because of high population sizes
and low generation times. In the 50's they found a bacteria that had evolved
to digest the synthetic material nylon. I wonder why bacteria haven't evolved
to digest plastic yet. Possibly there is some scientific reason that it's
inefficient to digest. Maybe we could speed evolution up by dissolving plastic
in a liquid first so it's more accessible to them.

~~~
neuronexmachina
There was actually a bacteria isolated last year which digests PET plastic:
[http://science.sciencemag.org/content/351/6278/1196](http://science.sciencemag.org/content/351/6278/1196)

------
rmason
There's already a much better solution to deal with plastic pollution, a
naturally degradable material made from corn.

We heavily subsidize both wind power and solar. We even still subsidize
gasohol even though it doesn't produce the environmental benefits we first
thought that it did.

But we don't subsidize degradable plastic made from corn which isn't used
widely because it costs a few cents more than plastic made from oil. That has
never made any sense to me.

~~~
riskable
You are grossly oversimplifying the issues. You're referring to Polylactic
Acid (PLA) which is made from corn and biodegradable. Except it only
biodegrades when eaten by bacteria _that only lives in soil_.

Meaning: If plastic made from PLA ends up in waterways, the oceans, etc it
won't degrade there and actually just breaks down into smaller parts creating
the exact same sort of problem as microbeads (except PLA doesn't last nearly
as long as other plastics regardless).

The other problem is that bioplastics have lower glass transition temperatures
than, say, PET or ABS which is what most plastic products are made from. So
you're not going to be using PLA in a car dashboard, for example since it
would deform rather quickly on a hot summer's day.

"But there's high-temperature PLA now!" Yes, yes there is. You know how they
make it "high temperature"? By adding fossil oil-based chemicals to the
polymer. This process results in PLA that leaves residues after degrading.
It's similar to "wood fill" or "bronze fill" filament in that a certain
percentage of it is PLA whereas the rest is the usual does-not-break-down-ever
stuff. Better? Yes. A long-term solution? Not really.

...and for reference, we _do_ subsidize bioplastics to the tune of billions of
dollars every year:

[https://farm.ewg.org/progdetail.php?fips=00000&progcode=corn](https://farm.ewg.org/progdetail.php?fips=00000&progcode=corn)

PLA and most other bioplastics are made from corn husks.

"Wait: I thought it was pretty much _all_ made from corn?" Nope! There's a
teeny tiny percentage of bioplastics made from algae. Now _there 's_ the
future!

~~~
Houshalter
Subsidies to corn farmers don't go to bioplastic producers. Corn husks aren't
exactly a scarce resource and would otherwise be left rotting in the field.

------
philipkglass
This is scientifically very interesting but pretty much orthogonal to solving
problems with plastic pollution.

The worms can't live in landfills. If you could separate the plastic before
landfilling to feed it to worms, then you could just burn whatever separated
plastic can't be recycled. (Yes, that releases CO2, but so does having worms
and bacteria eat the plastic.) The problem with plastic as waste isn't that it
is super-toxic or impossible to destroy. The problem is that it's mixed in
with a lot of other kinds of waste. We don't need new ways to destroy
polyethylene. We need ways to separate it from mingled waste streams or
prevent mingling in the first place.

~~~
freeflight
>The problem is that it's mixed in with a lot of other kinds of waste. We
don't need new ways to destroy polyethylene. We need ways to separate it from
mingled waste streams or prevent mingling in the first place.

We already have these ways, they are called waste separation and recycling. As
a German, I've been separating my garbage for as long as I can think back:
Plastics, paper, organic waste and whatever remains as residual waste. In
addition to that, we have separate bins for glass bottles, if there's no
bottle deposit on them.

Residual waste bins are usually the smallest ones, so people are pretty much
forced to separate their waste if they don't want their residual waste bin
full after just one week.

It's always weird to me when I'm in another country and everybody just throws
everything into the same bin, bottles included, just feels so wrong to me at
this point.

~~~
literallycancer
Well, since you can't put food stained plastics in the plastic bin (or do you
guys do it?), it has to go into the residual waste, and it's that way with
many things.

~~~
freeflight
>Well, since you can't put food stained plastics in the plastic bin.

Why couldn't you? If it's just stained it's not much of an issue after all the
food is biodegradable and will just rot on its own from bacteria and insects.

There are some people actually washing out their plastic garbage to prevent
bad smells coming from their plastic garbage bag. Imho that's a massive waste
of water, just put the garbage bag somewhere where the smell does not bother
anybody, the stuff is garbage after all so it's not supposed to smell like
roses.

~~~
literallycancer
Lipids are an issue for the recycling process. Some people wash them yes, but
then you spend more energy on washing than is saved by the recycling so it's
kind of pointless.

------
pc2g4d
One day, landfills are vibrant ecosystems that completely break down whatever
is placed inside them. As a compost pile today is to plant waste, a landfill
one day could be to plastic, glass, metal, styrofoam, etc. We just need to
save the planet long enough that evolution can run its course and some
lifeforms start taking advantage of all the energy locked inside our "waste".

~~~
freeflight
> We just need to save the planet long enough that evolution can run its
> course and some lifeforms start taking advantage of all the energy locked
> inside our "waste".

You realize evolution works in timeframes that are like really really long? On
an evolutional timescale 2000 years is pretty much nothing, to us humans it's
pretty much our whole modern history of massively polluting this planet.

The pace with which we are changing this planet is way too fast for evolution
to keep up with it. If changes to the environment are so fast and so radical
then no living thing has time to adapt, they will be extinct before having any
chance at adaption.

~~~
Houshalter
Well that's a very long time for animals yes. Bacteria reproduce as fast as
every half hour. In that 2000 years, that's 35 million generations of
bacteria. You can go through a thousand generations in 3 weeks. And every
landfill has hundreds of trillions of them. Constantly mutating and competing
for resources.

~~~
freeflight
If life on Earth would only consist of bacteria you would have a point, but
there's quite a bit more variety to it.

------
ajarmst
Oh, yeah, I know how this ends. A year from now, when we're chest-deep in
caterpillars, you're going to offer to sell us some caterpillar-eating
birds...

~~~
djsumdog
We already have troubled bee populations throughout the world too. I could
also see us getting rids of insane amounts of plastic bags (boo-yea!) and then
losing all bee pollinating crops (e.g. Almonds) as colonies collapse (boo-
nah?)

~~~
accountyaccount
If I have to choose one of these:

* almonds

* plastic bags

* bees

RIP the planet.

------
nnutter
Three orders of magnitude greater than previously known plastic eating
bacteria.

------
TeMPOraL
Would be good to have plastic waste broken down, but be careful not to take
down our whole civilization with it. Almost everything today is made out of
plastic...

~~~
nkrisc
In many post-apocalyptic works of fiction it's a disease that wipes out much
of humanity; what if instead it was a bacteria or pest that rapidly consumes
all our plastic that causes civilization to collapse?

~~~
Asooka
We've been building things out of wood for a long time and wood is a food
source to plenty of organisms. If that was going to make civilization
collapse, it wouldn't have risen in the first place.

~~~
castis
Yes but wood has a pre-existing cycle already in place. Plastic hasn't existed
for as long as wood has. If a new microbe or whatever evolves to feed on
plastic and becomes widespread, it would certainly be a new experience for us.

~~~
weberc2
I think material science has advanced enough that in 99% of cases, we could
find some other suitable replacement (e.g., glass, aluminum, cloth, leather),
albeit at a higher cost (although perhaps lower when you account for
environmental impact). I'm guessing the remaining 1% of cases are in medicine
or some other advanced science.

------
s0rce
What is new here compared to the linked paper from 3 years ago?
[https://phys.org/news/2014-12-gut-bacteria-worm-degrade-
plas...](https://phys.org/news/2014-12-gut-bacteria-worm-degrade-plastic.html)

------
chicob
Isn't this a terrible idea in the large scale? By allowing animals to eat
plastic, won't their metabolism release CO2 to the atmosphere through
respiration? Plastic has lots of carbon.

Isn't this the same as burning some plastic and saying 'plants can eat it
now', just without the direct emissions?

In the small scale, it can solve some local problems. But in the larger scale,
shouldn't we just bury plastic deep underground? Of convert it to fuel in
substitution of further fossil fuel extraction?

------
maverick_iceman
Link to the original paper: [http://www.cell.com/current-
biology/abstract/S0960-9822(17)3...](http://www.cell.com/current-
biology/abstract/S0960-9822\(17\)30231-2)

------
kangnkodos
What exactly comes out the other end? Small pieces of plastic?

~~~
Symbiote
"The analysis showed the worms transformed the polyethylene into ethylene
glycol, representing un-bonded 'monomer' molecules."

Moderately toxic, but breaks down in the air in about 10 days. Used in
antifreeze.

[https://en.wikipedia.org/wiki/Ethylene_glycol](https://en.wikipedia.org/wiki/Ethylene_glycol)

~~~
giarc
Interesting... is this why I've never heard any issues with the amount of
windshield washer fluid that is used? I got through many litres every winter.

~~~
Arizhel
Probably. The primary complaint I've heard about ethylene glycol is that it
smells sweet and it's poisonous, so it attracts animals (esp. dogs and cats)
and kills them. It's not highly concentrated in windshield washer fluid, but
it is in engine coolant, so sometimes people would leave it out and their dog
would drink it and die (and the death was awful IIRC due to the way the poison
worked). Years ago, there were some alternative antifreezes offered which used
propylene glycol instead: it doesn't attract animals the same way, and has
nearly the same (but not quite) antifreeze performance. It seems to have died
out though.

~~~
jacquesm
It kills people too. Kids, adults poisoning others (or themselves). Bad stuff,
better keep it locked away.

~~~
sithadmin
Kills people = bad stuff, keep it locked away is a pretty dangerous, slippery
slope.

~~~
jacquesm
How so? Sweet smelling liquids that kill and children are not compatible in
the same space. That's a pretty good reason to keep your various cleaning
stuff out of the reach of toddlers whose need to experiment exceeds their
capability to understand.

~~~
Arizhel
True, but isn't this basic common sense? We do exactly the same with other
poisonous chemicals in the house: drain cleaner, etc. Of course, most of them
aren't sweet-smelling like antifreeze, but you also don't use antifreeze in
the house, only in the car.

I think the real problem with antifreeze is when people drain their radiators
at home and then leave the old antifreeze out, either because they're too lazy
to put it in a sealed container right away, or because they're letting it
evaporate instead of figuring out how to dispose of it properly. Then,
usually, some animal comes across it (and is attracted by the smell).

------
myegorov
In my experience, common clothes moth[1] or its larvae is also capable of
eating through a plastic bag enclosing dry foodstuffs or cereal. Not sure if
they're actually digesting it or could survive on the polyethylene diet
though.

[1]
[https://en.wikipedia.org/wiki/Tineola_bisselliella](https://en.wikipedia.org/wiki/Tineola_bisselliella)

~~~
eric_h
This is somewhat orthogonal to your point, but my cats are also perfectly
capable of eating through a plastic bag enclosing dry foodstuffs (left a
sealed bag of cat treats on the counter one day, found it chewed through and
empty the next).

It does seem likely to me, however, that the number of insect species capable
of eating through plastics and also breaking the plastic molecules down must
surely number greater than one.

------
jogjayr
This is the best news I've heard all month!

The levels of abraded plastic in our water have gone up steadily over the past
half century. While not so much of an immediate threat as rising CO2 levels,
it's still something we'll have to contend with eventually. Not to mention the
eyesore that is plastic waste. If they can make this work at industrial scale
it will really be something!

------
pehtis
Looks like this has been know for years...

[http://pubs.acs.org/doi/abs/10.1021/es504038a](http://pubs.acs.org/doi/abs/10.1021/es504038a)
[http://www.smithsonianmag.com/smart-news/plastic-loving-
bact...](http://www.smithsonianmag.com/smart-news/plastic-loving-bacteria-
worms-gut-could-help-break-down-our-pollution-problem-180953528/)
[http://news.stanford.edu/pr/2015/pr-worms-digest-
plastics-09...](http://news.stanford.edu/pr/2015/pr-worms-digest-
plastics-092915.html)

------
titojankowski
I bet YC or IndieBio would jump at a project like this, great startup
potential.

Scaling up enzymes ftw! Anyone interested?

IndieBio, $250k seed investment:
[http://indiebio.co/companies/](http://indiebio.co/companies/)

~~~
dmix
Sounds like something littered with government regulations and patents. I stay
away from anything bio for that reason. Hopefully this one finds some
motivated individuals who can take it to industrial scale though.

~~~
titojankowski
I imagine most government regulations (i.e. FDA) would apply to
pharmaceuticals or medicines. Since this isn't being ingested (FDA) or grown
in a field (EPA), I would think it's ok. What did you have in mind?

------
egwynn
File under “Diet of Worms”

------
smithkl42
If there's so much plastic in the ocean, and if it's (obviously) possible for
something to evolve in such a way that it can use plastic for nutrition - it
seems like we just need to wait a bit, and we'll get some bacteria or weird
fish or something like that to solve our floating garbage problem for us. No?

~~~
virmundi
You're right. Unfortunately this also means our non garbage plastics are at
risk. For example there is a fungus that converts cloth and similar trash to
fuel. It also was a major problem in WWII.

[https://www.scientificamerican.com/podcast/episode/C8ED057F-...](https://www.scientificamerican.com/podcast/episode/C8ED057F-D32E-34B5-4DF78025550EB35B/)

------
partycoder
Reminds me of the nylon-eating bacteria discovered in the 70s in Japan.

It generates an enzyme that digests nylon (nylonase).

[https://en.wikipedia.org/wiki/Nylon-
eating_bacteria](https://en.wikipedia.org/wiki/Nylon-eating_bacteria)

------
DrScump
The paper:

[http://www.cell.com/current-
biology/fulltext/S0960-9822(17)3...](http://www.cell.com/current-
biology/fulltext/S0960-9822\(17\)30231-2)

------
jfoutz
Once a bacteria evolves that has a taste for plastics, we might have some
trouble. It's probably not a very energy dense food source, but abs burns
pretty well. There's some power there

------
tossaway322
Yet another reason to buy a M1911 instead of a Glock:

Range Instructor: "Mr. Johnson, where's your sidearm?

Mr. Johnson: "I'm sorry sir, the caterpillars ate it!"

But seriously folks, this may turn out to be a problem. I already have ants
eating the plastic in my house's wiring.

"'Crazy' Ants, New Invasive Species, Destroys Electric Wiring, Unfazed By
Conventional Pesticides":

[http://www.huffingtonpost.com/2013/06/10/crazy-ants-
invasive...](http://www.huffingtonpost.com/2013/06/10/crazy-ants-invasive-
species-destroys-electric-wiring_n_3415153.html)

This situation is getting out of hand. We need worm- and insect-resistant
plastics, obviously!

------
buschtoens
I'm not a chemist, but I find it really interesting that some enzymes seem to
be so versatile that they can destroy chemical bonds they did not originally
evolve for.

------
ourmandave
There's a new Godzilla movie coming in 2019 which is supposed to be a series
that revisits all the classic monsters.

Perhaps this could be the new Mothra original story.

------
namuol
Are there any efforts to use computation to discover possible enzymes to solve
problems like this?

------
dghughes
Now we're going to end up with plastic butterflies.

~~~
pcrh
From Very Hungry Caterpillars.

------
macawfish
These kinds of things give me tremendous hope.

------
notadoc
Sooo, cover garbage dumps in caterpillars?

------
accountyaccount
i have traveled back in time to warn you that in the future we have too many
caterpillars

------
olleromam91
So what do they poop it out as? Something less pollutant than plastic?

------
ams6110
The caterpillars are infected with the Andromeda strain, evidently.

------
jayeshsalvi
Are they sure it doesn't shit plastic back?

------
snappyTertle
Next story: Caterpillars die from plastic poisoning :(

------
ensiferum
A typical round about way for human civilization. Since plastic is an
environmental problem a logical solution would have been not to produce and
use it. Or at least manage its lifetime better. But of course the industry
doesn't care about cleaning up since there's no money there.

~~~
jeffdavis
On what basis do you claim that your solution is logical, but using a
caterpillar is not?

~~~
ensiferum
If something is a an environmental problem which do you think is better.

a) not create the problem in the first place

b) start creating a solution to the environmental problem you created

~~~
cokeandsympathy
Is the problem posed to the environment from plastics greater than the human
benefit from their use?

