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Newly discovered deep-sea enzyme breaks down PET plastic

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

#61

Post by m463 »

dzdt wrote: post #47

The way to understand the origin of fossil fuel deposits is that hundreds of millions of years ago trees were made of plastic. Thats not quite literally true but it gives the right sense. In the Carboniferous period trees grew abundently but there were not yet bacteria that could break down the lignins composing the woody structure. Its very similar to what you'd get with plastic trees today: they would fall and pile…

It's interesting to read about thomas gold's theories about hydrocarbons.

https://en.wikipedia.org/wiki/Abiogenic_petroleum_origin

To me it makes sense that some or all hydrocarbons are or at least started like the hydrocarbons found on other planets in our solar system.

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

#64

Post by testfoobar »

gilleain wrote: post #51
testfoobar wrote: post #34

Earlier quoted context omitted.

"this is a feruloyl esterase with a conserved alpha/beta-hydrolase fold but with an additional flexible 'lid' domain that covers the active site" As educated as I think I am, it is always humbling to read a hacker news comment that I cannot understand. ELI5?

Apologies, that was meant for the specialists :) It is mostly just technical jargon so do not feel too humble ... So I'll break it down: - "feruloyl esterase" : an 'esterase' is an enzyme that makes or breaks ester bonds. In this case, 'feruloyl' which I've never heard of but apparently is some small molecule that is normally attached to a sugar. https://en.wikipedia.org/wiki/Feruloyl_esterase - "conserved alpha/beta…

Thank you.

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

#65

Post by digging »

Intralexical wrote: post #56
digging wrote: post #38

Earlier quoted context omitted.

More reason to be furious at plastic peddling billionaires. They made us hostages. We still have to stop them, but it's going to hurt even more.

Eh. Thinking plastic would last forever was probably a reasonable assumption at the time. I doubt it was the billionaires making that design call. Though in hindsight maybe we should have known better, given the history of lignin and natural waxes. Though especially given the history of lignin, we probably have millions of years before medical devices being eaten by microbes becomes a widespread problem that anyone s…

> Thinking plastic would last forever was probably a reasonable assumption at the time

That's... not what I'm mad about at all.

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

#66

Post by anon84873628 »

testfoobar wrote: post #34
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…

"this is a feruloyl esterase with a conserved alpha/beta-hydrolase fold but with an additional flexible 'lid' domain that covers the active site" As educated as I think I am, it is always humbling to read a hacker news comment that I cannot understand. ELI5?

I don't think there's much to say besides "slightly different chemical structure makes it better". At some point you hit jargon rock bottom.

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

#67

Post by Gibbon1 »

neftaly wrote: post #57
testfoobar wrote: post #34

Earlier quoted context omitted.

"this is a feruloyl esterase with a conserved alpha/beta-hydrolase fold but with an additional flexible 'lid' domain that covers the active site" As educated as I think I am, it is always humbling to read a hacker news comment that I cannot understand. ELI5?

Enzymes are kind of like a tool for breaking apart lego blocks, or a jig for assembling them. This sounds like a moving part that covers the "teeth" and makes it more effective (or less likely to get jammed by the wrong molecules?).

Two things.

Lot of reactions are energetically favorable. But the reactants are stuck in a local minima. So either doesn't happen or is too slow. Enzymes mediate the reaction so it can happen or happen faster.

Lot of reactions there are side reactions that produce stuff you don't want. Resulting a terrible yield or maybe none. Enzymes can promote the reaction you want increasing the yield.

Interesting thing to watch for is eletrocatalysts. Where you use electricity and a catalist to push a reaction that is energetically unfavorable. Like CO2 + H2O --> methanol. These may become very important as we stop pumping oil and gas out of the ground.

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

#68

Post by dzdt »

morsch wrote: post #54
dzdt wrote: post #47

The way to understand the origin of fossil fuel deposits is that hundreds of millions of years ago trees were made of plastic. Thats not quite literally true but it gives the right sense. In the Carboniferous period trees grew abundently but there were not yet bacteria that could break down the lignins composing the woody structure. Its very similar to what you'd get with plastic trees today: they would fall and pile…

When I searched for this, I found there to be some debate on it (isn't there always?): https://www.pnas.org/doi/10.1073/pnas.1517943113 https://arstechnica.com/science/2016/01/why-was-most-of-the-...

Thanks! Your newer research is pretty convincing. Makes me a bit sad: I really like the 'plastic tree' analogy. Ah, well.

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

#69

Post by coffeebeqn »

Kerb_ wrote: post #21
kzrdude wrote: post #7

Earlier quoted context omitted.

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 impl…

It would still be difficult for bugs to gnaw on solid plastic

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

#70

Post by bno1 »

dzdt wrote: post #47

The way to understand the origin of fossil fuel deposits is that hundreds of millions of years ago trees were made of plastic. Thats not quite literally true but it gives the right sense. In the Carboniferous period trees grew abundently but there were not yet bacteria that could break down the lignins composing the woody structure. Its very similar to what you'd get with plastic trees today: they would fall and pile…

I wonder what forests looked back then. Trees going through and on piles of dead trees?
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