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I wonder how much evolution pressure you must exert onto a living thing for it to start consuming something as complex as plastic. And how many generations past

I wonder how much evolution pressure you must exert onto a living thing for it to start consuming something as complex as plastic. And how many generations past time they are not in the lab anymore they figure out there’s simpler solutions to nutrition, especially in the gut.

ben-schaaf 4y ago
Not having any competition for a food source is a very strong pressure, so much so that multiple plastic eating bacteria have already been discovered.
Qem 4y ago
If we consider lignin as the first plastic (not man-made), it took about 60 million years. See https://www.nationalgeographic.com/science/article/the-fantastically-strange-origin-of-most-coal-on-earth https://www.nationalgeographic.com/science/article/the-fanta...
andai 4y ago
There was a story on HN today about a plastic-eating enzyme: >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. https://news.ycombinator.com/item?id=31427011 https://news.ycombinator.com/item?id=31427011 Maybe one of the human gut bacteria could be modified to also produce this enzyme? Though presumably it would be outcompeted by the natural variant (assuming dissolving plastic confers it no advantage). Also, I have to wonder if the monomers are more harmful than the plastic? Being smaller particles they might perhaps end up in the bloodstream?
- moffkalast 4y ago
  > Maybe one of the human gut bacteria could be modified to also produce this enzyme? Fantastic, now I can not only eat the food, but also the packaging! Can we get one for cellulose too? Then we can eat pizza while it's still in the box.
  - sp332 4y ago
    You can, there are cellulase enzymes sold for human consumption. I don't know how much cellulose you'd be able to eat in one sitting, though. Cellulase is pretty slow.
  - krageon 4y ago
    And for keratin, so nail biting becomes a type of recycling.
- joshspankit 4y ago
  We’d have to have a huge array of enzymes to deal with the dizzying array of chemicals we group in under “plastic”. For example, the linked article specifically targets polyethylene terephthalate which they say is a huge target because it accounts for 12% of all plastic waste.

ben-schaaf 4y ago

Not having any competition for a food source is a very strong pressure, so much so that multiple plastic eating bacteria have already been discovered.

Qem 4y ago

If we consider lignin as the first plastic (not man-made), it took about 60 million years. See https://www.nationalgeographic.com/science/article/the-fantastically-strange-origin-of-most-coal-on-earth https://www.nationalgeographic.com/science/article/the-fanta...

andai 4y ago

There was a story on HN today about a plastic-eating enzyme: >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. https://news.ycombinator.com/item?id=31427011 https://news.ycombinator.com/item?id=31427011 Maybe one of the human gut bacteria could be modified to also produce this enzyme? Though presumably it would be outcompeted by the natural variant (assuming dissolving plastic confers it no advantage). Also, I have to wonder if the monomers are more harmful than the plastic? Being smaller particles they might perhaps end up in the bloodstream?

moffkalast 4y ago
> Maybe one of the human gut bacteria could be modified to also produce this enzyme? Fantastic, now I can not only eat the food, but also the packaging! Can we get one for cellulose too? Then we can eat pizza while it's still in the box.
- sp332 4y ago
  You can, there are cellulase enzymes sold for human consumption. I don't know how much cellulose you'd be able to eat in one sitting, though. Cellulase is pretty slow.
- krageon 4y ago
  And for keratin, so nail biting becomes a type of recycling.
joshspankit 4y ago
We’d have to have a huge array of enzymes to deal with the dizzying array of chemicals we group in under “plastic”. For example, the linked article specifically targets polyethylene terephthalate which they say is a huge target because it accounts for 12% of all plastic waste.