I've often wondered about this. Does the chemistry imply the energetics of this would be less favourable than other organic decomposition?
This could be bad too I suppose? Pipes and other chemical containment vessels might come under attack.
I think this does mean that plastic things could soon rot. It could be pretty interesting based on how it spreads. Call a remediation company because you noticed the plastic-mold growing in your house somewhere.
"Dammit the TV's rotting!"
I remember reading an old SciFi book many years ago (decades?) about the scenario where a rapid plastic eating bacteria gets into the world.
Wish I could remember the name of it, as I roughly remember the book as being pretty good too. :)
Do you mean the Andromeda Strain by Michael Crichton [1] (also a movie) and I seem to remember it being a good watch when I last watched though that might be a good 15 years ago. The idea was novel enough it's stuck with me since and I do often joke with people about it, especially given from what I gather that certain types of funghi can now digest certain types of plastic [2].
[1] https://en.wikipedia.org/wiki/The_Andromeda_Strain
[2] https://www.shroomer.com/mycoremediation-plastic-eating-mush...
Nah, it was definitely a different book. Thanks for trying though. :)
> I think this does mean that plastic things could soon rot.
In the presence of moisture, maybe. The are plenty of microorganisms that can break down wood and paper, yet they can still stay intact for centuries.
Time to invent a type of plastic that's poisonous to these bacteria!
> Is it harmful to humans?
> Not at all! You can definitely trust that my company has studied this in depth. I'm sure it isn't going to make it into everyone's bloodstreams before we learn it's actually terrible.
> before we learn it's actually terrible.
Before you learn it's actually terrible if I may.
[Busy covering up the 3000% cancer rates of the production line workers]
The paper frames this as microorganisms "exploring novel ecological niches." More accurate framing: we accidentally created a massive evolutionary pressure toward undoing one of our primary material technologies. And we can't stop it. Oops?
Polyethylene terephthalate is a little unique. Part of its popularity comes from recycling, because it is "easy" to break down. For other polymers like polystyrene or PVC it's not so easy.
But any plastic is going to be harder to break down than cellulose because life depends on water and plastics are usually hydrophobic. So non-porous things will always break down pretty slowly. Plenty of plants grow in the water, after all, and aren't immediately consumed by bacteria. Microplastics should, in principle, be the first things to go.
Robes are probably a big one as well - in the olden days (before plastics) any ropes you used in the sea would rot fairly quickly. Nowadays that obviously isn't a problem - we have really good fairly cheap robes made of plastic, but maybe in the future it will become a problem again
If life found a way to eat wood, surely it will find one of our plastics appetizing? Turns out, yes.
https://medium.com/@datavector/why-plastic-eating-bacteria-e...
It’s wild to me that for tens of millions of years, wood didn’t rot. It just sat there, piling up and occasionally burning.
Curiously near Chernobyl, decomposition microbes are suppressed, so things can hang around longer: https://www.smithsonianmag.com/science-nature/forests-around...
> for tens of millions of years, wood didn’t rot.
I love this story and have repeated it to many people because of how wonderfully it sparks the imagination. Unfortunately, this theory simply doesn't hold up to modern evidence. It turns out we've had white rot fungi as long as we've had lignin
> Throughout the fossil record, evidence of decay is pervasive in all organic matter exposed subaerially during deposition, and high coal accumulation rates have continued to the present wherever environmental conditions permit.
> Rather than a consequence of a temporal decoupling of evolutionary innovations between fungi and plants, Paleozoic coal abundance was likely the result of a unique combination of everwet tropical conditions and extensive depositional systems during the assembly of Pangea.
For this reason, Earth will never make new coal. New oil will be formed, but coal is mostly compressed cellulose. Today it would be digested instead.
Wood and other plant matter is still turning into peat under the right circumstances to this day. And peat is still slowly turning into various kinds of coal. It's true that the majority of coal (about 90%) originates from the carboniferous period, but microorganisms today does still not manage to break down all cellulose under all circumstances.
The Paleozoic peak in coal deposition was not due to white rot fungi evolution lagging behind lignin evolution. In fact we have plenty of evidence that fungi were pretty much always able to decompose lignin
https://www.pnas.org/doi/10.1073/pnas.1517943113
> Here, we demonstrate that lignin was of secondary importance in many floras and that shifts in lignin abundance had no obvious impact on coal formation. Evidence for lignin degradation—including fungal—was ubiquitous, and absence of lignin decay would have profoundly disrupted the carbon cycle. Instead, coal accumulation patterns implicate a unique combination of climate and tectonics during Pangea formation.
Wood has always been decomposable by fungi. The idea that there was a lag in evolution is a once-prominant myth that has since been disproven.
Plastics are not a single chemical. If anything it's more of a characteristic of a wide variety of polymers which are typically synthetically derived from petroleum are extremely varied. Even if fungi/bacteria eventually evolve the correct enzymes to break down some of the plastics, it's foolish to think all plastics will be solved by evolution. Especially since many of these enzymes result in other microplastic compounds instead of full decomposition.
It's also a little rash to hope for it given how much of the world's infrastructure would be threatened by such a development.
It's no surprise that microorganisms evolve quicker to adapt to environmental changes. (At least for evolutionary / genetic changes).
That makes me wonder if we'll soon see mammals with gut microbiomes that can digest microplastics.
Makes me wonder if we're building towards another extinction/oxygen catastrophe type of event. Not one where the microplastics themselves are the primary driver, but because microplastics are not renewable in the environment without humans. With solar energy transitions, greater pollution awareness, and a population that's shrinking or leveling off, what will happen to all of the microorganisms which spent a great deal of energy evolving ways to metabolize plastics that suddenly lose that source of energy? They're suddenly less fit for their niche.
Or in a different area of concern, what happens to the plastic economy when plastics are no longer useful because they'll be decomposed too quickly? Sanitary packaging for medical supplies come to mind.
That seems very far away. My understanding is that these PETases digest plastic VERY slowly and need human engineering efforts to digest it in any appreciable amount of time (hours to days rather than years). And human bioengineering of these enzymes is still not to the point where it's actually usable at industrial scale. The paper just says they've discovered the variants, not "oh no all animal life on earth is now dependent on microplastics" :D
> What happens to the plastic economy when plastics are no longer useful because they'll be decomposed too quickly?
We already use lots of biodegradable things for crucial applications, such as the wood used in framing houses. Just because wood can rot in a damp forest doesn't mean that the wood inside your walls will rot away just because. There are conditions where it can start rotting, and we're aware of those conditions and how to prevent them, at least enough for a house to last for decades.
Just because they can digest PET does not mean they cannot digest other things. Being able to switch between food sources as they become more or less abundant is a very common adaptation.
The lifespan of microorganisms is sufficiently short (in most cases) that you’re turning over the entire population regularly - the reason you see such rapid evolution in microorganisms is because they do an enormous amount of dying and procreating anyway. As such, it’s hard to really quantify what a microorganism extinction event would look like in a way that meaningfully distinguishes it from any random Tuesday.
I don't think they are unlearning how to eat other things. It's humans who will have to find a new way to build cars, planes, boxes, bottles and electronics. Think how expensive it will be once car tire or fiber-optic cable eating bacteria hits a major city. Your access to fresh food will be limited and you don't even have a single apple tree.
It turns out there are a lot of microorganisms (and bigger) that attack your apple trees. Nothing is easy.
>what will happen to all of the microorganisms which spent a great deal of energy evolving ways to metabolize plastics that suddenly lose that source of energy?
As the article implies, microorganisms evolve relatively quickly. So the answer is, they would evolve to consume another source of energy. (As has happened for the subjects of the article in the opposite direction.)
I think environmental conservation efforts would have to be fairly successful for your concern.
Fortunately, the US will see that possibility isn't very likely. In the 1980s, there was growing concern about the use of plastic and styrofoam one-time packaging. Both still widely used today…
On an evolutionary timescale, our plastic era probably won’t last very long, right? The byproducts might, but I guess if something learns to eat them, not so much.
Actually it seems pretty crazy that they are figuring it out so quickly (guess there’s lots of energy bound up in those molecules).
I guess we’ll have to go back to our old friends glass and copper. Petrochemicals were a fad anyway; glass and copper have been with us the whole time.
Though sand is actually becoming a problem commodity to source now, too:
https://www.clarknexsen.com/the-global-sand-crisis-examining...
https://scitechdaily.com/the-sand-crisis-no-one-is-talking-a...
https://www.bbc.com/future/article/20191108-why-the-world-is...
That's mostly a type of sand needed for concrete, sand which is relatively "young" and has not yet had the sharp edges ground off by wind and water. You need sharp sand in construction, because "round" sand leads to weaker concrete.
Sand for glassmaking is more than abundant enough for all but the most distant futures, and even then glass is extremely recyclable.
There was an article on here (sometime in the last year?) claiming that the concrete strength issue is a myth. Apparently it's based on a very narrow claim in a single academic paper that's been wildly extrapolated.
Well yeah, if we insist on continuing to burn our limited supply of hydrocarbons, soon(ish) we won't have enough for making plastics either. Or plastics will become prohibitively expensive...
This is not true in a practical sense. There is a lot of petrochemicals still out there and our ability to recover marginal reserves keeps improving. I was really into the idea of peak oil when I was younger but it really hasn't panned out. Rather, if we continue to using oil, we'll cook ourselves and drown ourselves in plastic.
The eventual end goal should probably be production of hydrocarbons using solar power and CO2/water. In other words, synthetic photosynthesis.
Yep, there isn't exactly a shortage of hydrogen, carbon or energy in the world. Currently we get all three from the same place, but there are other approaches
Copper is expensive. If I were looking for a plastic alternative, I would follow the beaten path and start with aluminum.
Yeah, I really look forward to seeing more research on the ability of these PETase genes to spread. The article touched on it briefly, but it’d be great to have more insight on how much of this is due to HGT vs. something likely to originate de novo across species.
> That makes me wonder if we'll soon see mammals with gut microbiomes that can digest microplastics.
On a less serious note, my cat is deadset on this accomplishment.
It might be a bad idea to digest plastics. If they get broken down in the gut, they'll release all those plasticisers and things into the body.
Evolution would figure that out over time with trial and error. We could instead get mammals with plastic nails/claws/hooves instead of keratin
e.g. keratin and cellulose are structural polymers not too different from materials like PET.
Can somebody do the napkin math on an estimate for how long for us to get plasticized hair and nails and teeth?
- [deleted]
If you're interested in this topic, I'd highly recommend checking out Michigan State's E coli Long-term Evolution Experiment: https://lenski.mmg.msu.edu/ecoli/index.html
I'm guessing evolution of these is driven more by microfibers from polyester cloth (which is also PET) rather than plastic bottles. The fibers have much higher surface area for bacteria to attack.
This is fascinating! Is this on-net good or bad for humans? On one hand, bacteria that consume plastics can help clean up the mess humans have produced, keeping the world somewhat more balanced. On the other, plastics are very useful to humans, so if they start "rotting" away this could cause lots of problems for society.
My guess is that this is on-net good for humanity. Curious what more qualified folks think.
Plastic is a hydrocarbon. If bacteria can metabolize it, we have a whole new source of GHG on our hands. It looks like 5–10% of petroleum ends up as plastic, which seems like a decently sized new supply of GHG to worry about. Even if we switched entirely to renewables tomorrow, we'd still have 5–10% of all of our emissions ever just sitting there waiting to eventually be released by bacteria. (Over what time span, I have no idea.)
Plastic was easy mode. Whatever we come up with to replace it is going to make things shittier somehow. In the form of more expensive processing and probably more exotically produced (harmful to humans working the plant).
I wonder if we really will come up with a replacement at all. Even if the bacteria can digest plastics, I can imagine that it may take N years to fully degrade a 0.125" piece. If N is 10 years, then maybe we just accept that plastics become unusable after 10 years for most applications -- For most of the things I use, I think this would be fine. Plumbing would be a disaster though. But if N is 1 year then ya, I think we'll need something totally new.
Plastics as in "polymers made of small organic monomers" are sort of a universal solution. Nature uses them a lot as well. For the same reasons we do, too.
So we could end up in a situation where we do ecological harm if we stop using plastics.
Probably not. All these critters definitely eat other stuff as well. And their non-plastic-eating cousins are probably still around anyway, and would just resume their former role if the plastic eaters died off.
As George Carlin suggested, maybe the only reason why the planet allowed us to evolve was to that it could have plastic: https://youtu.be/rld0KDcan_w?si=0h4qZFzO4S9ijwT0&t=204
This implies in the future plastic will rot like wood.
Yup. In most cases, not a big deal. Plumbing, however, is going to be a nightmare.
A lot of cities are in the process of replacing lead pipes with plastic. Replacing them again is going to be a huge burden, especially with an increasingly aging population and fewer people to do manual labor unless we have some sort of good automation for manual labor.
The replacement in some cases is to install a plastic liner rather than remove the pipe.
Protect your plastics with aluminum foil
the prophecy is true - https://youtu.be/rld0KDcan_w?si=WZkF45Ct-wsVCUWq&t=188
Life finds a way. Add a potentially usable food source in big enough numbers and the ones that take advantage of that will thrive.
But is PET their first and preferred energy source, or is it secondary when their primary energy sources are scarce?
algae eats jet fuel, fast enough that there are algasides added to discourage them.
plastcics are more or less like liquid hydrocarbons, with there lack of porosity as the thing that keeps them from bieng eaten, so that unlike most things plastics present a 2 dimensional surface where engulfing single or small groups of molecules is impossible, so other sort of feedingmechanism* must be at play to eat plastics.*
*off the cuff conjecture from a non specialist
Okay bacteria now do nuclear waste
We already have radiotrophic fungus, found near Chernobyl. Interestingly they appear to use melanin to absorb and utilise energy from the radiation.
It doesn't really eat the nuclear waste, it "just" feeds on the radioactive energi, so it doesn't speed up the decay. But you can use them as a radiation shield.
As far as I know you cannot speed up the decay, unless you put it in a particle accelerator and bombard it into something with a much faster half life?
Not exactly a scalable solution.
We just need particle accelerator mushrooms
That just gives you radioactive bacteria who might crawl around a bit and spread the radioactivity. You can't get rid of a nuclear problem by chemistry.
You are correct, of course, but in a sci-fi scenario maybe you could have a colony of fungi that move nuclear material around internally to keep it 'hot', thus 'burn it off' faster to extract energy. It might collect material from a wide area.
Heat doesn't impact radioactive decay, though the sci-fi fungi could have some internal neutron reflectors that may make something interesting happen
Well you misunderstood but also you aren't correct.
Hot is commonly used to mean radioactive. https://en.wikipedia.org/wiki/Hot_particle
One mode of radioactive decay is electron capture, which is absolutely impacted by temperature (just mentioning this as trivia, I meant hot-as-in-radioactive).
Moving around radioactive material doesn't affect its activity, unless you're specifically talking about collecting it into a near-critical mass or something like that. Presumably that's what GP was thinking about wrt neutron reflectors. And I'm pretty sure that only works even in principle if the isotope in question can be stimulated into activity by absorbing neutrons (or other radiation I suppose), which is not the case for all of them. Bio-accumulating a critical mass of radioactive material ion by ion... well, it sure is sci-fi.
Things happily eat nuclear waste. This is one of the big problems with nuclear waste, your body will happily integrate radioactive isotopes or heavy metals, which then slowly kill you.
Devastated there's a possible future where my game boy rots.
can PETases attack ABS? I think gameboys/legos are safe for now.