
An enzyme that digests plastic could boost recycling - dberhane
https://www.economist.com/news/science-and-technology/21740669-auf-wiedersehen-pet-enzyme-digests-plastic-could-boost-recycling
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fredley
I'm fascinated by this. It took 60 million years after trees evolved for
microbes to evolve that could digest them[1]. The resulting strata of
undigested tree are now most of our coal. Now of course, if a tree dies and is
left where it fell, it is usually digested entirely in a number of years by
microbial life.

What would happen if a microbe evolved that could feed itself from plastic?
And what if it got out of the lab? Imagine all the plastic items in the World
suddenly as susceptible to rot as wood. It would fundamentally change almost
every aspect our existence, in a very short amount of time.

[1]: [http://phenomena.nationalgeographic.com/2016/01/07/the-
fanta...](http://phenomena.nationalgeographic.com/2016/01/07/the-
fantastically-strange-origin-of-most-coal-on-earth/)

~~~
k_
It would be awesome if we could unleash something like this in our oceans
without doing harm to the ecosystem (would be hard to do more harm that what
we are already doing with plastic, but still).

~~~
endymi0n
I had the same exciting thought before it dawned on me that we usually choose
plastics _for a reason_. Imagine water bottles breaking down in the store.
Imagine protective coatings of ships breaking down. While I'd be happy for the
mess we created in the oceans, I'm unsure if this would just trigger another
arms race for more indestructible materials — that would clog the oceans once
again.

~~~
chiefalchemist
We chose plastics because it was cheaper. Yes, there are other benefits.
Unfortunately, no one asked, "If this stuff doesn't decompose, then what?" to
assess that risk vs the benefits.

Without that answer the use of plastics should have been mitigated a la
nuclear fission. Instead, micro bits of plastics are everywhere; the oceans
and their ecoayatem are compromised. Etc.

For what? Convenience and a few cents?

~~~
acdanger
I ask myself the same question about our current techno-commercial landscape.

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sytelus
I have been seeing articles on this topic for at least 5 years. What is
stopping this from becoming actual practical process than just PR release that
keeps poping up every now and then? Is there any real article on technical
problems in this area that are still unsolved?

~~~
Tepix
The article states that a 100-fold increase in efficiency is required before
it can be used.

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decebalus1
Can't help be reminded of this (awesome) book [1] where a bacterium is
engineered to eat PCBs and released in the wild without proper testing,
leading to very interesting side-effects.

I wonder what byproduct of this digestion would be. I don't want to sound like
a luddite but remember BPA?

[1]
[https://en.wikipedia.org/wiki/Zodiac_(novel)](https://en.wikipedia.org/wiki/Zodiac_\(novel\))

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rough-sea
Can someone link to a pdf of the actual paper?

Harry P. Austin el al., "Characterization and engineering of a plastic-
degrading aromatic polyesterase," PNAS (2018)

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Coincoin
> At the moment, a litre of a solution of even the improved enzyme would break
> down just a few milligrams of plastic per day. Its plastic-digesting ability
> must therefore be improved by a hundredfold or more to be commercially
> useful.

Good! The last thing we need right now is yet another source of CO2. I say
bury the thing, it's that much carbon sequestered for a few hundred years.

~~~
drdeadringer
What I have yet to understand is what happens in a few hundred years when all
this sequestered CO2 becomes not sequestered, and how this is not more "kick
the can".

~~~
Coincoin
It's pretty obvious what will happen; it will transform into CO2 into the
atmosphere. But at least it will have given us a few hundred years to figure
out instead of piling over the present mess.

~~~
drdeadringer
I'm all optimistic about technological innovation, but I have a doubt
regarding the will of the (at least politically) great and powerful. Is this
where the Free Market comes in a la Musk's future ilk?

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gadders
Don't forget the caterpillars that can do this as well:
[http://www.bbc.co.uk/news/science-
environment-39694553](http://www.bbc.co.uk/news/science-environment-39694553)

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JulianMorrison
We should engineer this into slime mold and release it into the wild to eat
litter.

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bawana
Anyone remember Andromeda strain? A bug that digests plastic was responsible
for the crash of a plane. Bacteria are too small to contain. They'll get out
somehow - on the worker's clothes, etc. And then they'll wreak havoc
(armageddon?) on this plastic world.

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kwhitefoot
Does anyone remember the first Doomwatch episode, the Plastic Eaters?

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mgeorgoulo
Life has an awesome way of turning disaster into opportunity!

~~~
spodek
Life made the disaster.

~~~
neolefty
There's a great song about that in the Lion King.

[https://www.youtube.com/watch?v=GibiNy4d4gc](https://www.youtube.com/watch?v=GibiNy4d4gc)

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jimjimjim
there was a judge dredd story way way back where the whole city was falling
apart because of something airborne that was eating plastic.

are we sure we want this?

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bcheung
George Carlin was right.

[https://www.youtube.com/watch?v=NBRquiS1pis](https://www.youtube.com/watch?v=NBRquiS1pis)

~~~
flarg
2000AD was at least as prophetic ...
[http://dreddalert.blogspot.co.ke/2014/01/judge-dredd-
great-p...](http://dreddalert.blogspot.co.ke/2014/01/judge-dredd-great-
plasteen-disaster.html?m=1)

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cooper12
We get an article like this every week. Wake me up when any of these miracle
solutions actually get put into practice. I'm still waiting for those graphite
batteries btw.

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dschuetz
"Digesting" enzymes? "Boost recycling"? That sound like a typical click bait.

It's actually an artificially engineered enzyme formerly discovered in certain
bacteria which is able to break PET molecules. Lots of potential, moving on.

~~~
Angostura
Nothing clickbaity there, that I can see. 'digest' is a very reasonable word
for enzyme-mediated breakdown, and it does have lots of potential in terms of
recycling, since the monomers can be reused.

~~~
43673232
Don’t have mission

