Plastic-Eating Enzyme Could Eliminate Billions of Tons of Landfill Waste 89
An enzyme variant created by engineers and scientists at The University of Texas at Austin can break down environment-throttling plastics that typically take centuries to degrade in just a matter of hours to days. Phys.Org reports: This discovery, published today in Nature, could help solve one of the world's most pressing environmental problems: what to do with the billions of tons of plastic waste piling up in landfills and polluting our natural lands and water. The enzyme has the potential to supercharge recycling on a large scale that would allow major industries to reduce their environmental impact by recovering and reusing plastics at the molecular level. [...] The project focuses on polyethylene terephthalate (PET), a significant polymer found in most consumer packaging, including cookie containers, soda bottles, fruit and salad packaging, and certain fibers and textiles. It makes up 12% of all global waste. The enzyme was able to complete a "circular process" of breaking down the plastic into smaller parts (depolymerization) and then chemically putting it back together (repolymerization). In some cases, these plastics can be fully broken down to monomers in as little as 24 hours.
Researchers at the Cockrell School of Engineering and College of Natural Sciences used a machine learning model to generate novel mutations to a natural enzyme called PETase that allows bacteria to degrade PET plastics. The model predicts which mutations in these enzymes would accomplish the goal of quickly depolymerizing post-consumer waste plastic at low temperatures. Through this process, which included studying 51 different post-consumer plastic containers, five different polyester fibers and fabrics and water bottles all made from PET, the researchers proved the effectiveness of the enzyme, which they are calling FAST-PETase (functional, active, stable and tolerant PETase). [...] Up next, the team plans to work on scaling up enzyme production to prepare for industrial and environmental application. The researchers have filed a patent application for the technology and are eying several different uses. Cleaning up landfills and greening high waste-producing industries are the most obvious. But another key potential use is environmental remediation. The team is looking at a number of ways to get the enzymes out into the field to clean up polluted sites.
Researchers at the Cockrell School of Engineering and College of Natural Sciences used a machine learning model to generate novel mutations to a natural enzyme called PETase that allows bacteria to degrade PET plastics. The model predicts which mutations in these enzymes would accomplish the goal of quickly depolymerizing post-consumer waste plastic at low temperatures. Through this process, which included studying 51 different post-consumer plastic containers, five different polyester fibers and fabrics and water bottles all made from PET, the researchers proved the effectiveness of the enzyme, which they are calling FAST-PETase (functional, active, stable and tolerant PETase). [...] Up next, the team plans to work on scaling up enzyme production to prepare for industrial and environmental application. The researchers have filed a patent application for the technology and are eying several different uses. Cleaning up landfills and greening high waste-producing industries are the most obvious. But another key potential use is environmental remediation. The team is looking at a number of ways to get the enzymes out into the field to clean up polluted sites.
Plastic-eating bacteria invented (Score:5, Insightful)
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I saw no indication that bacteria were in involved. The two links do not mention bacteria but neither do they say how the researchers produced the enzyme. Maybe it is buried in paper but that is behind a paywall.
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Researchers at the Cockrell School of Engineering and College of Natural Sciences used a machine learning model to generate novel mutations to a natural enzyme called PETase that allows bacteria to degrade PET plastics
Re:Plastic-eating bacteria invented (Score:5, Informative)
I saw no indication that bacteria were in involved. The two links do not mention bacteria but neither do they say how the researchers produced the enzyme. Maybe it is buried in paper but that is behind a paywall.
AFAICT there ARE bacteria involved - the bacteria manufacture the enzyme that breaks down the plastic. I couldn't find a substitute for the paywalled article, but I did find this:
https://www.frontiersin.org/articles/10.3389/fmicb.2020.571265/full
I bet it provides a lot of the context and background that might be gleaned from the paywalled publication.
Because the bacteria directly create compounds that can degrade plastic, I share GP's concern regarding genetic engineering. Unintended consequences and all that...
Re:Plastic-eating bacteria invented (Score:5, Interesting)
That bacteria getting out into the world and thriving might be more disruptive to human life than a nuclear winter.
Look around you, and think about everything that you can see that's made of plastic. It's all potentially digestable by bacteria in just a few months. Electronics, writing utensils, clothing and furniture, all our most common food storage methods, tooth brushes, tools, handles, everything in transportation, the coating on all of the wires everywhere, etc.
If this thing gets out into the wild and takes off, we'll be back to the 1800s in the blink of an eye, subsistance farming with metal tools and cooking in metal pans over wood fires. It's going to take decades to retool everything in modern life to use non-edible materials.
Re:Plastic-eating bacteria invented (Score:5, Insightful)
Maybe you hadn't noticed, but wood, cloth, and other natural substances are also broken down by bacteria/fungi and are heavily used by human beings. Like with any living things- they need certain conditions to thrive- moisture chief among them. I wouldn't hold my breath that somehow these will be "special" organisms that somehow don't require living in a damp environment to break down plastics.
Re: Plastic-eating bacteria invented (Score:2)
We use plastics in a lot of damp environments because of exactly this, wood and cloth break down. If we lose control, the areas where we rely on plastic - like water hoses, warm and wet, will be targets
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There is no way a bacteria can evolve or even be engineered to eat up all the world's plastic. It is physically and scientifically impossible. I mean, there are things already today that bacteria love and can efficiently metabolize but haven't depleted. If there is a bacteria that can eat plastic, in order for it to do maximum damage the plastic would have to be provided in wet form with a bunch of nutrients, ideally with a supply of amino acids. I mean, I routinely grow bacteria in my lab .. sometimes we h
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Re:Plastic-eating bacteria invented (Score:4, Insightful)
Question: What does the enzyme break the plastic down into? Anything useful? Something bad?
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Were I to guess, I'd guess something that is rapidly degraded into CO2. Unless it's done in an anaerobic environment, in which case I'd guess methane.
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I understand that the end product of depolymerisation is the monomer. I have read about this elsewhere. The monomer recovered from the digested plastic can be used to make new plastic. I don't know if the quality is good enough to use instead of freshly made monomer. The recycled stuff might have a lot of impurities.
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So the landfills will be toxic but they'll smell nice?
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Some of these monomers are indeed toxic. They tend to be highly reactive chemicals. I think the idea is to segregate the PET waste first, before digesting it with the enzyme. The (possibly toxic) monomers are extracted for recycling, leaving the less toxic waste for further processing or landfill. I don't think the intention is to add the magic enzyme to unsorted waste, which would have the effect you suggest.
Re:Plastic-eating bacteria invented (Score:5, Informative)
This is just an enzyme, they don't seem to have engineered a microbe to generate it. But yes, if they did and if it escaped to the wild, that would be a concern for anyone who uses PET in a container or for clothing (where it's more commonly called polyester) or whatever else.
Re: Plastic-eating bacteria invented (Score:3)
Re:Plastic-eating bacteria invented (Score:5, Informative)
This is just an enzyme, they don't seem to have engineered a microbe to generate it. But yes, if they did and if it escaped to the wild, that would be a concern for anyone who uses PET in a container or for clothing (where it's more commonly called polyester) or whatever else.
Except, pretty much all of large-scale synthesis of complicated proteins (such as enzymes) is done by splicing gene encoding it into some microbe, and letting it do its thing in a bioreactor. I'm not sure, but I think it'd be a pretty safe bet to say that such a microbe already exists.
Still, just being able to break the plastic up does not automatically mean being able to derive sustenance from it.
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Yep, a worrisome concept if it got into the wild. There was an interesting series of Science Fiction stories, about a post-WW III era where a Soviet-designed enzyme that ate petroleum got into the wild. Very bad news indeed. The story tracked a Soviet engineer outfit trying to escape the KGB-ruled USSR in a giant steam locomotive.
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What could possibly go wrong?
Is there anyone who did not wonder this? It has the potential to be either the saviour of the world or the destroyer of modern civilisation.
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Merely tweaked (Score:5, Interesting)
From a chemical energy point of view, all the plastic that we release is a juicy chunk of energy that one could recover.
(Plastic burns. Means that there's energy that could be harvested).
That means that a bacteria that has evolved to harvest it is bound to happen.
In fact it has already happened. There are Aeruginas which can digest plastic.
Pay attention to the summary above:
the scientist haven't invented a brand new enzyme de Novo.
the scientists have tweaked the already existing PETase, to produce a variant with a few tweaked more desirable characteristics (regarding speed, thermal range, etc.): FAST-PETase.
i.e.: such bacteria are already in the wild (e.g. reported detect in the Sargasso ocean gyre)
What could possibly go wrong?
Well, bacteria able to digest PET are going to use it and burn it as an energy source. Given the vaste amount of plastic that we've released into the nature, if a lot bacteria are doing it, we could expect it to have some impact on the CO2 released into the atmosphere.
(But I am completely unqualified to make even back-of-napkin estimates of whether this impact will be noticeable or drowned into our own release of CO2 through burning of foccile fuels.
Dr "Bones" McCoy's voice: I am a doctor, Jim! Not a climate scientist!)
Re:Plastic-eating bacteria invented (Score:5, Funny)
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And the beauty of it is that the gorillas die off over the winter!
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No worries. Once it escapes into the wild and starts eating the coating of electricity cables, we simply release another strain of bacteria that is trained to eat this one. Simples.
It's bacteria all the way down ...
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PET is made from Terephthalic acid and Ethylene glycol. Where wires are insulated with just about anything except PET. The closest and most common would be PE, which is made from ethylene. Another popular wire insulation is nylon which is amine and carboxylic acid. And PVC which is chloroethene / vinyl chloride. None of these are things the enzyme is likely to act on.
Now making an enzyme that can act on some of these others plastics is definitely possible. And one way to make enzymes on an industrial scale
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As others have pointed out electric wires are insulated with a different plastic. However your concern is very warranted. After all, the Puppetiers did something very similar on Ringworld causing the Fall Of Cities.
Trying to use knob and tube wiring in a modern house would be a challenge to say the least.
Diesel cars and trucks could still work, and they would have to use the old acetylene lanterns at night.
I wonder if the liquified plastic would make good lantern fuel?
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You just failed Chemistry 101. Enzyme = chemical != bakterium.
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So, scientific facts moderated down? Nice! I guess that "moderator" also does not understand the very basics.
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Agree to both of your statements.
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Sorry, but at least from the summary that's not clear. How is the altered enzyme made? If they grow bacteria, extract the enzyme, and modify it, or go for total synthesis (as *may* be implied) then your analysis is correct. If they modified the bacteria to produce the modified enzyme, then it's wrong.
OTOH, I've got a strong suspicion that it will only work on plastic surfaces in contact with either water or oil (not either one, I just don't know whether it's hydrophobic or hydrophilic), so it's probably
Remember "Doomwatch" from the 70s (Score:2)
An excellent TV series (though sadly many of the episodes are lost as their recordings were wiped in the name of cost saving).
One episode was expanded into a book (Mutant 59 - The Plastic Eater -- by Kit Peddler). I read it [too many] years ago -- I must re-read it sometime.
https://www.fantasticfiction.c... [fantasticfiction.com]
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They don't eat bacteria; they produce an enzyme that breaks it down, but they do not derive nutritional value from it, which is quite important and reduces any real threat.
Since the production of this enzyme is of no benefit to the bacterion, it will quickly evolve it away if it somehow escapes and it also produces it in quite smal dosages.
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Uh, bacteria can't live possibly ever live off plastic. Plastic lacks essential elements for reproduction. Like, I don't know .. phosphorous for example. In the same way, it can't live off sugar either. I mean, bacteria love sugar, but you can leave a mound of sugar on the table for a decade nothing will happen to it. Bacteria can't do anything to it. Ever seen mold growing on pure sugar?
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What could possibly go wrong?
Someone thought of that -- back in 1971: Mutant 59: The Plastic-Eaters [amazon.com]
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What could possibly go wrong?
Already covered in a sci-fi story I read around 1972.
Mutant 59: The Plastic Eaters. Great read!
https://www.goodreads.com/book... [goodreads.com]
https://www.amazon.com/Mutant-... [amazon.com]
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Can bacteria be engineered to produce this enzyme? (Score:2)
Re:Can bacteria be engineered to produce this enzy (Score:4, Insightful)
Ya, but more testing is required to make sure that enzyme doesn't attack creatures or other necessary ingredients for life. But like you, I am hopeful.
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The real question is, what would be annual PET -> CO2 (via MHET) conversion rate be? Instead of slowly crawling to the edge of no return, do we end up fucking punting ourselves over?
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This enzyme would be useful in controlled recycling environments. Where we could capture the gaseous effluent and use it in manufacturing of CNTs or synthetic fuels.
Re: Can bacteria be engineered to produce this enz (Score:2)
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If CO2 can be used as a feed stock, then . . . maybe? Remember that, at least as far as the article goes, we haven't been given much information as to how the enzyme behaves or what are the potential outputs from facilitated reactions. CO2 in-and-of-itself is a stable compound. Cracking it requires energy input. There is a modified Fischer-Tropsch process that can use CO2 as a feedstock, and I believe something similar to that is used in "green" fuel synthesis plants that absorb atmospheric CO2:
https://w [weforum.org]
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Well, sure, but then you go from environments contaminated with solid chunks of polyethylene terephthalate to environments contaminated with terepthalic acid molecules, along with copolymers like cyclohexanedimethanol. Sure those contaminated environments will *look* cleaner, but is that better?
There are only two way to eliminate waste: (1) transform it into something useful or (2) not generate it in the first place. If you transform waste into something *useless*, you're simply transforming it into anot
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You couldn't use this on landfill waste to "sort" out the plastics into waste forms that are storable in less space, or byproducts that you can reuse for other purposes? Is there something that makes it only suitable for pre-sorted plastic?
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Not to worry. This is just a small modification to an enzyme that a bacteria is already generating, and bacterial cultures evolve rapidly, so it's going to show up in the wild whatever we do. The problem is it only handles PET, do other plastic wastes will be untouched. (But perhaps there's a bacterium that has learned how to handle some of the others.)
..then what? (Score:2)
This last is inevitable, in the long term - but, as a species, we seem to want to live fast, die young -
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We should use cellophane more (Score:2)
One of the original plastics and entirely biodegradable yet its only used for small amounts of wrapping (here in the UK anyway) even though its suitable for short term food storage and general wrapping. Yes making it uses CS2 which is a pretty nasty chemical but then frankly making other plastics requires something a bit more noxious than fresh spring water and moonbeams too.
what could possibly go wrong (Score:2)
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Fiction is fiction. You don't improve your understanding of things by pretending that it's real.
The end product isn't ideal... (Score:2)
Sadly converting plastic into monomers isn't a solution either, since monomers can cause serious issues. And given they are smaller than microplastics, they can get into and stay in the foodchain even easier. This means our body won't have the microplastics anymore, it'll have to deal with much more monomers, which can cause a wide variety of things.
As usual, this is trying to fix a problem that should be addressed not by fixing the outcome but by fixing the production process.
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Well, it's an incomplete solution that proposed for application. But if PETs are degraded into monomers in a controlled setting, though monomers can be extracted and reused. Or be further degraded until you end up with CO2 or methane.
"Nice!" (in onslow's voice) (Score:1)
So we finally will get rid of plastic in where-ever it is in use today. No more plastic at the hospitals, in planes, cars, toys, clothes.. Its all gonna become some gray goo... :D
Explain like I'm 5 (Score:2)
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Exactly. If plastics take centuries to break down, that's good. Someday my county landfill will be covered with grass and picnic benches and will become a lovely park. Who cares what's in it, as long as it stays there.
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It won't stay there.
OTOH, the time scale will be multiple decades, so perhaps you don't care.
How will they use it? (Score:2)
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Doomwatch (Score:2)
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No more than your wooden house instantly collapsing because there are wood-eating bugs and bacteria. There are countless organisms that eat wood, and yet, we have no problem building huge structures out of wood and using it for countless purposes.
I bet you're fun at parties...
If your idea of a party is standing around dreaming up doom-and-gloom scenarios, you should go to better parties.
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Not at the parties where people make the same joke that 20 of the other guests just made, at least, but that's not on him.
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Slashdot is slowly teaching me that scientific outcomes differ depending on political leanings.
And this is how we end up with Tay the racist chatbot.
But yes, that IS what's happening to people. The human brain eventually interprets continuous exposure as truth. Repetition is one of the most fundamental laws of propaganda, if not the most fundamental. More generally, it's possible to convince the mammalian brain that anything is 'normal' with sufficient exposure/repetition. It's part of how the mammalian brain works. Repetition is the primary way by which religions have propagated for tens of tho
So what is the end product? (Score:2)
Okay, so it breaks down plastic. Into what?
Thermal combustion breaks down plastic into nasty shit like dioxin. What is the end product of this process? More oil? Dioxin? Inert carbon?
Anime Plot (Score:2)
Ill wind (Score:2)
What could possibly go wrong? (Score:2)
Dumping tons of synthetic enzymes into a cauldron of "food" for them, and letting them swim around underground, mutating in the dark for a long time while they work....
I can't see that evolving into something that literally eats a substance used in nearly every facet of our modern civilization. Nope, not at all.
DUNE karma (Score:2)
Worms!
Just dissolve it inorganically (Score:2)
PET is highly soluble in trifluoro acetic acid and trichloro acetic acid. There is no need for the high tech engineering of bacteria to produce novel enzymes. Well, except the need to use your toys and get papers published.
https://www.sciencedirect.com/... [sciencedirect.com]
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PET is highly soluble in trifluoro acetic acid and trichloro acetic acid.
Giant vats of trifluoro and trichloro acetic acid. Do you want The Joker? Because that's how you get The Joker.
Building Materials (Score:2)
Steel rebar used in concrete structures and pour of slabs have this nasty habit of rusting out and falling apart over years when relief cuts are made into sidewalks or when pipes burst underground. Plastic rebar, on the other hand, doesn't have this issue and works great in standard home building, sidewalks, and other residential slab pours. This alone would reduce a huge amount of steel dependence from foreign countries.
The big issue w/ recycling is that there're so many different plastics out there and
Mutant 59 is real! (Score:1)
A true prophetic British show from the 70s...
Mutant 59: The Plastic Eaters (Score:2)
What could possibly go wrong?
https://www.amazon.com/Mutant-... [amazon.com]
I'm less worried about all this as time goes on. (Score:2)
Sure, in the short term we'll have our own problems. But even if we cause a true mass-extinction event, no biggie. Whatever emerges will eat whatever poison we introduced, and life will continue on its merry way. We can't permanently salt these fields. We can change the paradigm going forward, but we can't stop the process.