So in less than a 100 years we’ve seen most of the antibiotics that were first invented now almost useless due to the bacteria they were designed for now being immune.
eg see:
so what’s the likelihood that a bacteria or algae will evolve to be able to breakdown the vast amounts of non degradable PET type plastic which is now littered all through the biosphere? is it not possible because that type of plastic just doesn’t contain anything thats a feasible food source for any type of organism?
if a plastic eating bactera/algae did spread widely and plastic bottles etc couldn’t be used for long term storage and shipping (as they’d get eaten and spoil) would that be a good thing for the environment overall or a bad thing?
edit: arghh typo, can a mod change the title to “bacteria or algae will evolve?”
plastic bags in the sea eventually breakdown to tiny microscopic particles but I don’t think they degrade back into things that can be taken up by the ecosystem.
according to what i’ve read PET bottles and plastic bags that are buried never degrade, I’ve seen estimates of thousands of years, and it’s not breaking down by biological action but essentially by geological action (eg water erosion)
There are already known bacteria that break down some plastics.
Given that plastics are a significant concentration of energy, we might regard them as providing a mostly unoccupied ecological niche waiting for evolution to fill. So, on that basis we might regard the evolution of somewhat more aggressive organisms that eat plastic as inevitable.
However its isn’t going to be all that quick I suspect. Bacteria don’t exactly work well when dry, and the plastic would really need to be permanently wet, or at least keep a film of water on it. (Of course bacteria already form sheets than can do this in damp environments.) Other useful materials that are subject to attack might form a useful guide as to what to expect. Wood for instance. Keep it dry and it will last for centuries. Plastics are unlikey to be worse than wood, and most likely significantly better.
Plastic is a very broad term. It covers essentially any useful polymer. Some are going to be much more resistant to attack than others. PTFE is probably going to be pretty immune.
So, evolution of organisms that eat a wider range of plastics, and probably do it more agressively when they can is probably a given. But the evolution of organisms that wreck our ability to use plastics in much the manner we currently do, is rather unlikely.
Many years ago there was an April 1st article in a local boating magazine, about a new species of microscopic marine shrimp that ate polyester. A fiberglass boat could be infested and reduced to a worthless pile of unsound junk in a matter of days. It was a nice bit of writing, with just enough ring of plausibility to it to make one pause for thought.
I write “organism” rather than bacteria above because I suspect that fungi may turn out to be an even more important agent of plastic degradation. Possibly in symbiosis with bacteria.
well maybe, but the question is, does non biodegradeable (eg PET) plastic contain substances which are feasible as energy sources for any organism? Maybe the leap required for something to metabolise PET plastic is so far from any current organism that it can’t happen…
This kid is using bacteria to degrade plastic bags. Link. The bacteria he is using are already being used or researched for use to clean up petroleum wastes. There is a huge amount of research towards using bacteria to clean up tar sands waste. Bacteria are pulled from contaminated sites, and tested to see which chemicals they can degrade. The best degrading bacteria produce a lot of surfactants that dissolve the hydrocarbons and allow the hydrocarbons to diffuse more rapidly to the bacteria, resulting in more growth and more surfactants. Ultimately, a biological consortium (BC) will be found that can degrade everything; if you do it you can call it Your_Name Your_Favourite_Animal :). I’m not joking, there is a product out already called BioTiger!
It would be interesting to see what a tar sands BC could do to PETs and other plastics. However, I think it would be much cheaper, faster, and have an equal environmental impact to just burn the plastic. This sort of biodegradation would take place in a plant like a water treatment facility. If it could happen reliably in the wild, it would be happening already in the wild. After the plastic is biodegraded, the carbon is released to the environment. Fire would release the carbon to the environment much more cheaply than biodegradation.
The problem with burning the plastics is the nasty side chemicals associated with that process. That, and the carbon being released into the atmosphere is probably something hopefully to be avoided, rather than the carbon being ingested, then deposited on/in the ground when the organism eating it dies.
I don’t believe it works that way. If I chop down an acre of trees, and leave them there to rot (ie, being eaten by microorganisms), the vast bulk of that carbon is going into the atmosphere, not the ground. The same would be true of plastics.
Also, I reported the OP in hopes that a mod will come by and edit the title.
I think we’ll eventually find or engineer critters that can digest plastics. However, I see two significant hurdles
It must be harder than it seems. Natural tar and asphalt pits provide a place where we’d expect to see something able to eat hydrocarbons. There are microorganisms adapted to survive in the stuff, but they eat other stuff that falls in - nothing can actually break even naturally occurring hydrocarbons down in a way that fits what the OP hopes for.
Do we really want it? Imagine the hell in your household if some microorganism were able to digest the insulation on your wires, the washers in your faucets, the weather stripping around your doors, the frames of your windows, your car’s tires and your underwear. We could control this, I’m sure, but the effort and hazards involved would not be desirable.
I would think such evolution would take a while. It’s a different type of change than the one resulting in antibiotic-resistant bacteria.
Anti-biotic resistant bacteria are just the descendants of bacteria that happened to already have some resistance in their genes. They survived, while other bacteria died. So they can reproduce, thus each generation there are more of them around. Eventually, most of the common bacteria are resistant to the most common antibiotic medicines.
But to evolve to eat plastic, they would have to develop a new ability, that of eating & surviving on plastic. They don’t do that now, so it’s completely new. It would seem that this would require a spontaneous change in the genetics of some bacteria, to give them this new ability. Then, if it provides an evolutionary advantage*, they would tend to reproduce faster. But such a new ability is different, and harder, than just the survival of the fittest of bacteria that happen to be resistant to antibiotics.
And I’m not sure this would be an evolutionary advantage. The ‘food’ that current bacteria eat is probably more common on earth than plastics.
Wasn’t it the premise of the first episode of Sliders or some similar parallel-world-jumping TV series, that they jumped to a world where all the plastic AND petroleum had been eaten by bacteria, so they were back to horse-carts and hot-air ballons.
Aah, got it - it was GRR MArtin’s failed TV pilot, Doorways.
It sounds like the main barrier to plastic-eating bacteria is the physical composition and hydrophobic nature of polymers and hydrocarbons. Bacteria can’t eat plastic because they can’t break it down into small bits to take inside and work on with enzymes.
So it seems to me the real question is, how hard would it be for a species of beetle to develop with symbiotic plastic-eating bacteria? We already have beetles which eat wood, horn, hair, bone, and other tough and otherwise inedible materials, often using symbiotic bacteria to perform the final chemical breakdown. It would seem to me feasible to me to pair some novel species of beetle with hydrocarbon-digesting bacteria. I don’t know if such a thing is at all likely to evolve on its own, or if you’d need deliberate genetic engineering to develop it.
Plastic, as waste, is relatively harmless - certainly not more harmful than the hydrocarbons that it came from. Of course the locations are a bit different as Plastic is close to the surface and still interacting with the eco-system while petroleum is far below and interacting with a much smaller portion of the ecosystem and no one wants to spend the money to put the plastic back where we got it.
But consider this - we will, someday, run out of plastic. As we’ve discussed in other threads the mining of landfills will become very viable and profitable when the need for plastic continues beyond the ability too sustain petroleum extraction. We don’t want plastic eating bacteria to exist unless their waste product is something we would value more than Plastic.
This is true if it is safely sequestered in a landfill. But it’s likely inevitable that some plastic will escape into the ecosystem, where it harms fauna that think it resembles food, and continues to do so due to its persistence. Presumably this, along with aesthetics, constitute reason enough to wish for a plastic-eating-and-breaking-down bug of some type.
But this just isn’t true. Even if we use all available petroleum, we have the capability to create plastics from biomass feed stocks. I imagine we’d be way more likely to scale that up than go to landfill mining. That may be useful for recovering elements like metals, but unlikely to be so for complicated compounds like plastic that are hard to reuse without downcycling.