8 ms·

Plastic-eating caterpillars: An escape from a shopping bag triggers an idea

139 points by rahulshiv 9y ago

sillysaurus3 9y ago
Non-paywalled article: http://archive.is/0Ja6H http://archive.is/0Ja6H
userbinator 9y ago
This actually sounds a bit scary, and I hope doesn't become reality, since it might turn out to be like termites --- given how much we rely on plastics, the damage caused by an inadvertent release or application could be severe. Also, polyethylene is one of the simplest plastics and can be recycled quite effectively; so the real problem is getting people to reuse and recycle, and not disposal. Much of it comes from petroleum sources so a nontrivial amount of energy was already spent in its production too.
- thatcat 9y ago
  "If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable." It seems like the intent is to find the mechanism of action and transfer it to a microbe. Could be super useful in oceans and other places that micro plastics are common.
  - dx034 9y ago
    I'd still keep them in a filter rather than releasing those microbes to the ocean. We don't know what other effects this could have on life.
    - lostlogin 9y ago
      As far as I’m aware, rubbish dumps are lined with a membrane to help control leaching. Having this membrane attacked would be fairly unhelpful. https://en.m.wikipedia.org/wiki/Composite_liner https://en.m.wikipedia.org/wiki/Composite_liner
- 52-6F-62 9y ago
  I think your second point is the most pertinent. I recall hearing about this subject a while back. Frankly, I wonder why (besides the loud sound of the Sunchip bags[0]) that cellulose and other bioplastics aren't utilized more—at least for common and commonly-dispensed items like beer-can rings, food wrappers, and other short-term packaging. --- [0] https://vimeo.com/9664621 https://vimeo.com/9664621
  - userbinator 9y ago
    and other short-term packaging The main problem with biodegradable plastics is that they have an inherent "expiry date", the countdown to which begins basically upon manufacturing. Product which could be stored for an unexpectedly long time may start degrading too early and thus become prematurely unusable. Trying to avoid waste myself, I've had a few times where I reused plastic bags which were biodegradable, without being too aware of it, and had some bad surprises when they functioned exactly as designed and disintegrated at the worst of times. Personally, I'm not a fan of biodegradables --- they seem to be a way for the manufacturers to keep making things which don't last as long, a sort of forced obolescence, under the guise of being "green". Also, overall it probably takes more energy to produce these materials than recycling existing plastics.
    - 52-6F-62 9y ago
      > a sort of forced obsolescence, That's a good point I hadn't considered. I was referring more specifically to really temporary storage. For instance, those baby spinach containers are usually made of bioplastics because the contents expire rapidly no matter your intentions. There are often other vegetable or grocery-shelf products that might not have long shelf-lives or delayed uses that could utilize the plastics. Surely we could divide the products into long-life and short-life? I'm speaking mainly to food products here. I don't see the immediate need to eradicate all plastics from use! I regularly keep my grocery plastic bags and reuse them time and time again. I should have been more specific! That said, it looks like the costs required to manufacture bioplastics are reducing[0]. The problem with non-bioplastics being that many of the refuse that people don't properly recycle will be here maybe long after you and me, or we can just punt it on down the generational-line, but as we've been witness to more recently that doesn't seem to be a great strategy. --- [0] https://phys.org/news/2015-07-biodegradable-plastic-cheaper-greener.html https://phys.org/news/2015-07-biodegradable-plastic-cheaper-...
- legulere 9y ago
  Reduce comes before reuse and recycle. There are several countries with 0 landfill rates and high recycling rates in Europe, but that doesn’t solve the problem. We actually need to re-evaluate our use of plastic.
  - smhost 9y ago
    https://www.youtube.com/watch?v=nYDQcBQUDpw https://www.youtube.com/watch?v=nYDQcBQUDpw For some ideas about how to cut waste. A different approach, with emphasis on recycling: https://www.youtube.com/watch?v=eym10GGidQU https://www.youtube.com/watch?v=eym10GGidQU As much as the internet likes to make fun of people like this, I honestly don't see anything wrong with what they're doing. And they look happy and healthy.
  - icc97 9y ago
    I'm not sure how true that is [0]: > What the “0” landfill means is that no waste is landfilled without pre-treatment… In 2014 there was only Germany that claims 0 landfill (subject to the above disclaimer) and there's 6 self reported countries that claim below 10%. [0]: https://www.zerowasteeurope.eu/2014/04/and-the-best-waste-performing-country-in-europe-is-estonia/ https://www.zerowasteeurope.eu/2014/04/and-the-best-waste-pe...
- jobu 9y ago
  > Also, polyethylene is one of the simplest plastics and can be recycled quite effectively Polyethylene can be recycled, but depending on the price of oil it's often cheaper to make new things than try to recycle them. Planet money did an episode a few years back that talked about this: https://www.npr.org/sections/money/2015/03/27/395815221/episode-613-trash https://www.npr.org/sections/money/2015/03/27/395815221/epis... "One day it's profitable to recycle a bottle. The next day, some number in the global economy changes and that bottle suddenly becomes trash."
  - ZeroGravitas 9y ago
    Just because something is cheaper, or more profitable, doesn't make it the right thing to do. You'd ideally include externalties that are not captured by the price. To give one related example, just dumping your trash in the street is cheaper than paying people to come and haul it away but no one seems to make the argument all about cost in that case. Particularly in the US, propaganda campaigns against the entire concept of recycling seem to have been very succesful. Often these are pushed by libertarians and you can trace the funding back to the Koch brothers who (entirely coincidentally of course) are invested in companies that supply the virgin feedstock materials to make new plastic bags or whatever. They've also spend millions on anti-EV and anti-solar campaigns two other rival industries where their product is only "better" if you totally ignore externalities.
  - DigitalJack 9y ago
    If you are of the belief that we have reached or will soon reach peak oil, then this sounds like a business opportunity for temporal recycling in the form of stockpiling the plastic until recycling it is valuable.
voiper1 9y ago
>Another question is the composition of their faeces. If these turn out to be toxic, then there will be little point in pursuing the matter. In other words, we don't even know if they _digest_ the plastic, or just eat it. If they don't digest it, there's no utility....
- astura 9y ago
  No, they digest them. Here's another article with more information. https://phys.org/news/2017-04-caterpillar-bags-biodegradable-solution-plastic.html https://phys.org/news/2017-04-caterpillar-bags-biodegradable... >To confirm it wasn't just the chewing mechanism of the caterpillars degrading the plastic, the team mashed up some of the worms and smeared them on polyethylene bags, with similar results
  - setr 9y ago
    Thats one hell of a test..
    - pbhjpbhj 9y ago
      Scientist 1: it may be an enzyme in the caterpillars, how we can we test for that Scientist 2: well how about we anaestetise the caterpillar and use a microfilament to extract the gut contents, then we can ... Scientist 1: <splat>
      - logfromblammo 9y ago
        I'd just put them in the centrifuge that they use to liquefy mice.
        codeisawesome 9y ago
        Oh God. There is a centrifuge to liquify mice?!
        9y ago
astura 9y ago
Previous discussion: https://news.ycombinator.com/item?id=14185891 https://news.ycombinator.com/item?id=14185891
partycoder 9y ago
There is also nylonase, or the nylon eating bacteria https://en.wikipedia.org/wiki/Nylon-eating_bacteria https://en.wikipedia.org/wiki/Nylon-eating_bacteria
doitLP 9y ago
Potential downsides to consider: 1. What happens when we remove the "negative" side of using plastic products? Why use less if the worms can eat it all? I'm guessing production and consumption of single use polyethylene products will increase. 2. What if the worms escape control, (like the possums in New Zealand, the farmed salmon in the pacific etc etc) then what sort of new disaster do we have on our hands?
- setzer22 9y ago
  Even if the worms turn out to be good for plastic disposal, I still don't see how that implies your first point. The products with which plastic is made are still a limited resource.
- dx034 9y ago
  To your first point, I don't think we currently reduce plastic at all. There are some people who want to reuse and switch to alternatives but in general, plastic usage is not limited by environmental factors currently. So I doubt we'd use more plastics if we can safely recycle it all.
merraksh 9y ago
See also https://news.ycombinator.com/item?id=14185891 https://news.ycombinator.com/item?id=14185891
_pmf_ 9y ago
What could possibly go wrong?
aaron695 9y ago
This is pointless. Once you have collected it bury it, burn it or recycle. If anything this will just release CO2? or Methane?
- dx034 9y ago
  Harvesting methane in a controlled environment could be used to generate electricity. And even if it's pure CO2 it would be cleaner than current methods.
YokoZar 9y ago
The waxworms in the article eat polyethylene. Common meal worms are capable of eating another plastic, polystyrene -- you can observe this yourself by just grabbing some from a pet store and putting them in a styrofoam container for a few days. In the case of the mealworms, the digestion is coming from gut bacteria, but it remains unclear how waxworms are able to do it with polyethylene.
Cthulhu_ 9y ago
Looks like instead of worms, they should focus on the enzymes that can break down the plastics. Apply gratuitously during waste processing and add them to landfills.
andreasley 9y ago
This was in April 2017. A more recent report questions the previous publication: "Although the biochemical decomposition has not yet been disproven, the sensational report of plastic eating caterpillars at least appears highly doubtful in the light of these results." [1] [1] https://www.sciencedaily.com/releases/2017/09/170915144156.htm https://www.sciencedaily.com/releases/2017/09/170915144156.h...
- vorotato 9y ago
  what about this? "To confirm it wasn't just the chewing mechanism of the caterpillars degrading the plastic, the team mashed up some of the worms and smeared them on polyethylene bags, with similar results. Read more at: https://phys.org/news/2017-04-caterpillar-bags-biodegradable-solution-plastic.html#jCp" https://phys.org/news/2017-04-caterpillar-bags-biodegradable...
Coincoin 9y ago
>Article title: Plastic-eating caterpillars could save the planet Wait, since when is plastic the main menace to our planet? >Another question is the composition of their faeces. Yeah, it would suck if it produced even more CO2 and methane. Even if we can catch the methane to make energy, that's more CO2 that would have been otherwise sequestered.

139 points by rahulshiv 9y ago

Non-paywalled article: http://archive.is/0Ja6H http://archive.is/0Ja6H

This actually sounds a bit scary, and I hope doesn't become reality, since it might turn out to be like termites --- given how much we rely on plastics, the damage caused by an inadvertent release or application could be severe. Also, polyethylene is one of the simplest plastics and can be recycled quite effectively; so the real problem is getting people to reuse and recycle, and not disposal. Much of it comes from petroleum sources so a nontrivial amount of energy was already spent in its production too.

thatcat 9y ago
"If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable." It seems like the intent is to find the mechanism of action and transfer it to a microbe. Could be super useful in oceans and other places that micro plastics are common.
- dx034 9y ago
  I'd still keep them in a filter rather than releasing those microbes to the ocean. We don't know what other effects this could have on life.
  - lostlogin 9y ago
    As far as I’m aware, rubbish dumps are lined with a membrane to help control leaching. Having this membrane attacked would be fairly unhelpful. https://en.m.wikipedia.org/wiki/Composite_liner https://en.m.wikipedia.org/wiki/Composite_liner
52-6F-62 9y ago
I think your second point is the most pertinent. I recall hearing about this subject a while back. Frankly, I wonder why (besides the loud sound of the Sunchip bags[0]) that cellulose and other bioplastics aren't utilized more—at least for common and commonly-dispensed items like beer-can rings, food wrappers, and other short-term packaging. --- [0] https://vimeo.com/9664621 https://vimeo.com/9664621
- userbinator 9y ago
  and other short-term packaging The main problem with biodegradable plastics is that they have an inherent "expiry date", the countdown to which begins basically upon manufacturing. Product which could be stored for an unexpectedly long time may start degrading too early and thus become prematurely unusable. Trying to avoid waste myself, I've had a few times where I reused plastic bags which were biodegradable, without being too aware of it, and had some bad surprises when they functioned exactly as designed and disintegrated at the worst of times. Personally, I'm not a fan of biodegradables --- they seem to be a way for the manufacturers to keep making things which don't last as long, a sort of forced obolescence, under the guise of being "green". Also, overall it probably takes more energy to produce these materials than recycling existing plastics.
  - 52-6F-62 9y ago
    > a sort of forced obsolescence, That's a good point I hadn't considered. I was referring more specifically to really temporary storage. For instance, those baby spinach containers are usually made of bioplastics because the contents expire rapidly no matter your intentions. There are often other vegetable or grocery-shelf products that might not have long shelf-lives or delayed uses that could utilize the plastics. Surely we could divide the products into long-life and short-life? I'm speaking mainly to food products here. I don't see the immediate need to eradicate all plastics from use! I regularly keep my grocery plastic bags and reuse them time and time again. I should have been more specific! That said, it looks like the costs required to manufacture bioplastics are reducing[0]. The problem with non-bioplastics being that many of the refuse that people don't properly recycle will be here maybe long after you and me, or we can just punt it on down the generational-line, but as we've been witness to more recently that doesn't seem to be a great strategy. --- [0] https://phys.org/news/2015-07-biodegradable-plastic-cheaper-greener.html https://phys.org/news/2015-07-biodegradable-plastic-cheaper-...
legulere 9y ago
Reduce comes before reuse and recycle. There are several countries with 0 landfill rates and high recycling rates in Europe, but that doesn’t solve the problem. We actually need to re-evaluate our use of plastic.
- smhost 9y ago
  https://www.youtube.com/watch?v=nYDQcBQUDpw https://www.youtube.com/watch?v=nYDQcBQUDpw For some ideas about how to cut waste. A different approach, with emphasis on recycling: https://www.youtube.com/watch?v=eym10GGidQU https://www.youtube.com/watch?v=eym10GGidQU As much as the internet likes to make fun of people like this, I honestly don't see anything wrong with what they're doing. And they look happy and healthy.
- icc97 9y ago
  I'm not sure how true that is [0]: > What the “0” landfill means is that no waste is landfilled without pre-treatment… In 2014 there was only Germany that claims 0 landfill (subject to the above disclaimer) and there's 6 self reported countries that claim below 10%. [0]: https://www.zerowasteeurope.eu/2014/04/and-the-best-waste-performing-country-in-europe-is-estonia/ https://www.zerowasteeurope.eu/2014/04/and-the-best-waste-pe...
jobu 9y ago
> Also, polyethylene is one of the simplest plastics and can be recycled quite effectively Polyethylene can be recycled, but depending on the price of oil it's often cheaper to make new things than try to recycle them. Planet money did an episode a few years back that talked about this: https://www.npr.org/sections/money/2015/03/27/395815221/episode-613-trash https://www.npr.org/sections/money/2015/03/27/395815221/epis... "One day it's profitable to recycle a bottle. The next day, some number in the global economy changes and that bottle suddenly becomes trash."
- ZeroGravitas 9y ago
  Just because something is cheaper, or more profitable, doesn't make it the right thing to do. You'd ideally include externalties that are not captured by the price. To give one related example, just dumping your trash in the street is cheaper than paying people to come and haul it away but no one seems to make the argument all about cost in that case. Particularly in the US, propaganda campaigns against the entire concept of recycling seem to have been very succesful. Often these are pushed by libertarians and you can trace the funding back to the Koch brothers who (entirely coincidentally of course) are invested in companies that supply the virgin feedstock materials to make new plastic bags or whatever. They've also spend millions on anti-EV and anti-solar campaigns two other rival industries where their product is only "better" if you totally ignore externalities.
- DigitalJack 9y ago
  If you are of the belief that we have reached or will soon reach peak oil, then this sounds like a business opportunity for temporal recycling in the form of stockpiling the plastic until recycling it is valuable.

voiper1 9y ago

>Another question is the composition of their faeces. If these turn out to be toxic, then there will be little point in pursuing the matter. In other words, we don't even know if they _digest_ the plastic, or just eat it. If they don't digest it, there's no utility....

astura 9y ago
No, they digest them. Here's another article with more information. https://phys.org/news/2017-04-caterpillar-bags-biodegradable-solution-plastic.html https://phys.org/news/2017-04-caterpillar-bags-biodegradable... >To confirm it wasn't just the chewing mechanism of the caterpillars degrading the plastic, the team mashed up some of the worms and smeared them on polyethylene bags, with similar results
- setr 9y ago
  Thats one hell of a test..
  - pbhjpbhj 9y ago
    Scientist 1: it may be an enzyme in the caterpillars, how we can we test for that Scientist 2: well how about we anaestetise the caterpillar and use a microfilament to extract the gut contents, then we can ... Scientist 1: <splat>
    - logfromblammo 9y ago
      I'd just put them in the centrifuge that they use to liquefy mice.
      - codeisawesome 9y ago
        Oh God. There is a centrifuge to liquify mice?!
        9y ago

astura 9y ago

Previous discussion: https://news.ycombinator.com/item?id=14185891 https://news.ycombinator.com/item?id=14185891

partycoder 9y ago

There is also nylonase, or the nylon eating bacteria https://en.wikipedia.org/wiki/Nylon-eating_bacteria https://en.wikipedia.org/wiki/Nylon-eating_bacteria

doitLP 9y ago

Potential downsides to consider: 1. What happens when we remove the "negative" side of using plastic products? Why use less if the worms can eat it all? I'm guessing production and consumption of single use polyethylene products will increase. 2. What if the worms escape control, (like the possums in New Zealand, the farmed salmon in the pacific etc etc) then what sort of new disaster do we have on our hands?

setzer22 9y ago
Even if the worms turn out to be good for plastic disposal, I still don't see how that implies your first point. The products with which plastic is made are still a limited resource.
dx034 9y ago
To your first point, I don't think we currently reduce plastic at all. There are some people who want to reuse and switch to alternatives but in general, plastic usage is not limited by environmental factors currently. So I doubt we'd use more plastics if we can safely recycle it all.

merraksh 9y ago

See also https://news.ycombinator.com/item?id=14185891 https://news.ycombinator.com/item?id=14185891

_pmf_ 9y ago

What could possibly go wrong?

aaron695 9y ago

This is pointless. Once you have collected it bury it, burn it or recycle. If anything this will just release CO2? or Methane?

dx034 9y ago
Harvesting methane in a controlled environment could be used to generate electricity. And even if it's pure CO2 it would be cleaner than current methods.

YokoZar 9y ago

The waxworms in the article eat polyethylene. Common meal worms are capable of eating another plastic, polystyrene -- you can observe this yourself by just grabbing some from a pet store and putting them in a styrofoam container for a few days. In the case of the mealworms, the digestion is coming from gut bacteria, but it remains unclear how waxworms are able to do it with polyethylene.

Cthulhu_ 9y ago

Looks like instead of worms, they should focus on the enzymes that can break down the plastics. Apply gratuitously during waste processing and add them to landfills.

andreasley 9y ago

This was in April 2017. A more recent report questions the previous publication: "Although the biochemical decomposition has not yet been disproven, the sensational report of plastic eating caterpillars at least appears highly doubtful in the light of these results." [1] [1] https://www.sciencedaily.com/releases/2017/09/170915144156.htm https://www.sciencedaily.com/releases/2017/09/170915144156.h...

vorotato 9y ago
what about this? "To confirm it wasn't just the chewing mechanism of the caterpillars degrading the plastic, the team mashed up some of the worms and smeared them on polyethylene bags, with similar results. Read more at: https://phys.org/news/2017-04-caterpillar-bags-biodegradable-solution-plastic.html#jCp" https://phys.org/news/2017-04-caterpillar-bags-biodegradable...

Coincoin 9y ago

>Article title: Plastic-eating caterpillars could save the planet Wait, since when is plastic the main menace to our planet? >Another question is the composition of their faeces. Yeah, it would suck if it produced even more CO2 and methane. Even if we can catch the methane to make energy, that's more CO2 that would have been otherwise sequestered.