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Newly discovered deep-sea enzyme breaks down PET plastic

phys.org

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Re: Newly discovered deep-sea enzyme breaks down PET plastic

#21

Post by Kerb_ »

kzrdude wrote: post #7
multiplegeorges wrote: post #6

So dumping all our plastic in the sea will work out! /s It seems like these discoveries are coming quickly and in higher numbers. Maybe there's hope in recycling/processing plastics down simpler molecules after all. Currently, recycling plastic is a bit of a lie -- very little of it is actually recycled.

I'm fearing that degradable plastics is also a lie.. is it just turning it into microplastics small enough that the problem visually disappears?

It breaks them down into their atomic components and enables bacteria that can straight up digest plastic. The issue from this is that we rely on plastics not being degradable for a lot of the properties we use it for. Imagine if bugs got this enzyme in their gut bacteria, and started eating the food wrappers instead of just nibbling through them. Plastic used to seal sterile equipment in medical settings or for implants? Useless. The plastic waste would only last a few years relative to the decades+ now, but it would also ruin plastic's ability to seal stuff, which is why we use it.

Overall, probably a good thing to reduce our reliance on plastic, but it will come at a cost, it's not just "we can dump plastic in the ocean now"

Re: Newly discovered deep-sea enzyme breaks down PET plastic

#22

Post by titzer »

multiplegeorges wrote: post #6

So dumping all our plastic in the sea will work out! /s It seems like these discoveries are coming quickly and in higher numbers. Maybe there's hope in recycling/processing plastics down simpler molecules after all. Currently, recycling plastic is a bit of a lie -- very little of it is actually recycled.

I recognize the sarcasm in your first sentence, but I am not super hopeful. The question is always, "so now it breaks down...into what? And what happens to that?". If that gives rise to the equivalent of some kind of algal bloom that then kills off other life, it might actually be worse than the microplastics themselves.

I for one do not hold out hope for recycling plastics. We had more sustainable materials in the past, and in places we still do that. For example, reusing beer bottles with the Pfand system in Germany, or milk bottles, crates, durable packaging. We're still going backwards with this consumerist throwaway culture.

Re: Newly discovered deep-sea enzyme breaks down PET plastic

#23

Post by jamesjuicy55 »

pneumic wrote: post #8
gilleain wrote: post #3

Slightly misleading headline, as PET (polyethylene terephthalate) hydrolases were already known - see https://www.chm.bris.ac.uk/motm/PETase/PETaseh.htm This is a study of an archaeal enzyme (from the deep-sea) that can degrade both long-chain and short-chain polymers that is more efficient at 70 deg C than other enzymes. The details are that this is a feruloyl esterase with a conserved alpha/beta-hydrolase fold but…

Yeah, it's not bad news at all but it appears to be one of many that still require considerable heat, industrial infra, etc. Has anyone attempted to put these enzymes to the test in at some scale in an industrial setting, I wonder?

https://www.purecycle.com/who-we-are. ?

Re: Newly discovered deep-sea enzyme breaks down PET plastic

#24

Post by EGreg »

titzer wrote: post #22
multiplegeorges wrote: post #6

So dumping all our plastic in the sea will work out! /s It seems like these discoveries are coming quickly and in higher numbers. Maybe there's hope in recycling/processing plastics down simpler molecules after all. Currently, recycling plastic is a bit of a lie -- very little of it is actually recycled.

I recognize the sarcasm in your first sentence, but I am not super hopeful. The question is always, "so now it breaks down...into what? And what happens to that?". If that gives rise to the equivalent of some kind of algal bloom that then kills off other life, it might actually be worse than the microplastics themselves. I for one do not hold out hope for recycling plastics. We had more sustainable materials in the p…

Here here.

Unfortunately the government has teamed up with the corporations to continue to push it for decades:

https://magarshak.com/blog/?p=362

The recycling was a scam to keep the public distracted so their impulse to “do something” would lead to individuan action rather than lead to organizing to demand reforms!

Re: Newly discovered deep-sea enzyme breaks down PET plastic

#26

Post by BizarroLand »

hanniabu wrote: post #15
hansvm wrote: post #11

Earlier quoted context omitted.

Humans are pretty adaptable. If half our stuff did become useless do you think that might put a damper on rampant consumerism?

It would increase consumerism since everything would need to be replaced on a periodic basis

With new plastics full of chemicals that the bugs won't eat.

Re: Newly discovered deep-sea enzyme breaks down PET plastic

#29

Post by hutzlibu »

multiplegeorges wrote: post #6

So dumping all our plastic in the sea will work out! /s It seems like these discoveries are coming quickly and in higher numbers. Maybe there's hope in recycling/processing plastics down simpler molecules after all. Currently, recycling plastic is a bit of a lie -- very little of it is actually recycled.

"Currently, recycling plastic is a bit of a lie -- very little of it is actually recycled."

Depends where you live and what you consider recycling. If you mean, making new plastics out of the old, than the challenge is, that there are many, many different plastics you cannot just melt in and reuse if mixed together. A annoying, but working solution here in germany is a mandated bottle bill. Meaning you pay 25 cent extra per bottle, and get it back, if you return that bottle into a machine: but this results in actual reusable plastics as they are all of the same kind.

And for the rest, the most pragmatic solution is burning it for energy. If you use filters, it is not so bad and it is recycling, but it is the same as burning fossil fuels, so not a good long term solution.

Re: Newly discovered deep-sea enzyme breaks down PET plastic

#30

Post by Max-q »

As much plastic as we dump into nature now, we increase the chance for a mutation of a microbe being able to digest it.

If that microbe manage to multiply and spread, plastic can start to rot, just like wood is doing now. On a long term basis, that might be a good thing, but in the short term it would be a catastrophy. We are using plastic as a long lasting material, often with no surface treatment. Imagine if wire insulation, waterproof encapsulation, gaskets and other important parts of our infrastructure starts to rapidly degrade!

That alone should be motivation for cleaning up and stop spreading plastic waste in nature.

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