In a practical sense there are lots of things here that run in the face of this. Plastics aren’t necessarily a good source of energy, for example, so whether plastivore bacteria could ever practically decay plastics in the way you’re imagining self sufficiently is dubious. The main purpose of the wild modifications is to provide a means to digest, but that comes at the cost of energy in the enzymes being produced to do that. We see an overall economic benefit, but it may mutate out rapidly if it’s not actually providing a singular benefit to the organism.
Plastic generally already corrodes outdoors very readily. That’s the primary source of micro plastic is that exact corrosion. Those that don’t would be equivalently hard to digest.
I mean sure, if you’re talking just manipulating some cell mechanisms to produce the enzymes required for digestion like we manipulate yeasts and e. coli to make drugs - the bugs don’t actually use those for anything and they’d lose the trait out in the wild or just keep it as a vestigial mechanism in limited populations.
But I was thinking more in a sense of what happened to lignin digestion. In the end, it’s still a source of carbon that can be used as a building block and the chemical bonds can be broken up for energy, so there’s no reason to think there would be no pressure to evolve to eat the monomers once they’re there and to adapt the gene for the enzymes from ‘professional use’ to ‘personal use’ by the bugs.
Case in point - mushrooms eating fallen logs and strains of S. cerevisiae producing amylase. At some point it made ‘sense’ to just keep those and that gave them an evolutionary edge, so the trait remained. And now we have another pest on our hands - S. cerevisiae var. diastaticus, a pox on non-belgian breweries everywhere. And critters that eat improperly treated wood beams and cause unpleasantness in wood framed houses.
there’s no reason to think there would be no pressure to evolve to eat the monomers once they’re there and to adapt the gene for the enzymes from ‘professional use’ to ‘personal use’ by the bugs.
I directly address this evolutionary pressure and why there are, in fact, reasons to think it won’t behave like lignin digestion in the very comment youre responding to friend.
Lignin digestion is at the end of the day just a random set of mutations that stuck because they were useful. If they weren’t useful, to an individual organisms survival, they likely wouldn’t stick around, as might be the case with plastic digestion, and would be different fur every single plastic.
The same exact method would be used for adding enzymes to their genome in yeasts as you mention or in various organisms for plastic digestion.
It’s a fair view that something forcefully introduced by us would be more of an appendix than a fully integrated digestion-feeding system, I’ll agree to that. I guess I’m being overly optimistic in my assessment regarding the integration of such a mutation in stable populations and the link from digestion to feeding.
Practically, we would try to predict this for each enzyme we introduce, and wed get it wrong sometimes and right other times, some plastics might prove to be very tasty others might not. But in general I’d lean towards most plastic probably not getting natural decomposers, personally, but maybe!
In a practical sense there are lots of things here that run in the face of this. Plastics aren’t necessarily a good source of energy, for example, so whether plastivore bacteria could ever practically decay plastics in the way you’re imagining self sufficiently is dubious. The main purpose of the wild modifications is to provide a means to digest, but that comes at the cost of energy in the enzymes being produced to do that. We see an overall economic benefit, but it may mutate out rapidly if it’s not actually providing a singular benefit to the organism.
Plastic generally already corrodes outdoors very readily. That’s the primary source of micro plastic is that exact corrosion. Those that don’t would be equivalently hard to digest.
I mean sure, if you’re talking just manipulating some cell mechanisms to produce the enzymes required for digestion like we manipulate yeasts and e. coli to make drugs - the bugs don’t actually use those for anything and they’d lose the trait out in the wild or just keep it as a vestigial mechanism in limited populations.
But I was thinking more in a sense of what happened to lignin digestion. In the end, it’s still a source of carbon that can be used as a building block and the chemical bonds can be broken up for energy, so there’s no reason to think there would be no pressure to evolve to eat the monomers once they’re there and to adapt the gene for the enzymes from ‘professional use’ to ‘personal use’ by the bugs.
Case in point - mushrooms eating fallen logs and strains of S. cerevisiae producing amylase. At some point it made ‘sense’ to just keep those and that gave them an evolutionary edge, so the trait remained. And now we have another pest on our hands - S. cerevisiae var. diastaticus, a pox on non-belgian breweries everywhere. And critters that eat improperly treated wood beams and cause unpleasantness in wood framed houses.
I directly address this evolutionary pressure and why there are, in fact, reasons to think it won’t behave like lignin digestion in the very comment youre responding to friend.
Lignin digestion is at the end of the day just a random set of mutations that stuck because they were useful. If they weren’t useful, to an individual organisms survival, they likely wouldn’t stick around, as might be the case with plastic digestion, and would be different fur every single plastic. The same exact method would be used for adding enzymes to their genome in yeasts as you mention or in various organisms for plastic digestion.
It’s a fair view that something forcefully introduced by us would be more of an appendix than a fully integrated digestion-feeding system, I’ll agree to that. I guess I’m being overly optimistic in my assessment regarding the integration of such a mutation in stable populations and the link from digestion to feeding.
Practically, we would try to predict this for each enzyme we introduce, and wed get it wrong sometimes and right other times, some plastics might prove to be very tasty others might not. But in general I’d lean towards most plastic probably not getting natural decomposers, personally, but maybe!