Environmental Pollution: Plastics

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Plastic bottles litter most of the world. There have been ongoing efforts to find methods to biodegrade PET, a very common plastic used for bottled water. British scientists have discovered an efficient way to get bacteria to "eat" PET plastic. A group at the Kyoto Institute of Technology in Japan that identified a new bacterium that was capable of "eating" polyethylene terephthalate, aka PET— the polyester plastic that is used for bottled water and other drinks. The Kyoto scientists named the bug Ideonella sakaiensis.

Perhaps most interesting was that Ideonella sakaiensis wasn't some ancient species that just happened to have some freakish properties that, by some amazing coincidence, was capable of breaking down a plastic first discovered in the 1940s. No – Ideonella was isolated from water near a recycling plant. Humans had inadvertently created it by supplying a bazillion water bottles. Bacteria in those waters evolved so that they could metabolize PET and use it for a food source, giving them an adaptive advantage over other bugs in the area.

Source: How Do Bacteria Eat Plastic?

Yes, those bacterium exist now thanks to both evolution and human help. The catch is that they can only eat certain types of plastic, not all plastics, yet. One also has to be careful what one wishs for though. Some plastic (like polystyrene or its trade name Styrofoam) contain rather toxic byproducts when broken down. If the bacteria evolve further to consume those types of plastics, it will create a much bigger pollution problem: carcinogens.

Mind blown! That a bacteria has evolved to eat any kind of plastic ...in my lifetime.

It eats only polyethylene terephthalate, aka PET— the polyester plastic that is used for bottled water and other drinks.

I obviously know that... you hockey puck! Jeez!

I meant "any" as in "of the many kinds of plastic it is a miracle that it can eat any AT ALL", as opposed to what you would expect: which is that it would "not be able to eat any of the many kinds kind plastic at all- not even one kind".

If a bacteria can evolve to eat PET, it potentially can evolve to eat other types also. The key is in the development of the specific enzymes that catalyze the breakage of the chemical bonds in the plastic. In a nutshell, the enzymes lower the activation energy for the reaction to take place in the polymer chain. This is something that can be genetically engineered, for both good or bad consequences.

BTW - There exists a modified bacteria strain that can turn cellulose from wood into a form of jet fuel. It would not be too much of a stretch to do the same with certain types of waste plastic sitting in the landfills. Currently, microwave energy can do this conversion somewhat, but it is not clean nor cheap to do. The right enzyme combination would change all of that.

We could breed bacteria to digest plastics. Then use them to "eat up" plastic in landfills. But then they might escape into the environment and attack stuff that isnt YET garbage. Eat the bushings in your car, and your plastic stuff that you're using, devour your computer, etc. Then we would be screwed!

With some modern cars, there would not be much left except a shell of metal. The bacteria would need to be contained by putting environmental locks on their ability to find plastic. We live in a mostly plastic world, so it would be an all you can eat buffet to them.

I could see genetically modified bacteria used in a chemical reactor vat digesting waste plastic from industrial sources. There might be some heat energy that can be captured and transformed into electrical energy during the process in bulk, but unlikely overall.

There's also a species of caterpillar larvae which can eat plastic, sound safer and more controllable than bacteria.

Really? Butterfly larvae? Or moth larvae?

If we decide breed bacteria we could breed them from anaerobic bacteria maybe. So if they escape then they will die from the (to them) toxic oxygen in the air of the outside world.

Two stories on companies repurposing plastic wastes:

- The Company Turning Plastics Back to Fuel:
https://www.bbc.co.uk/programmes/p063hj7c

- Story on companies incorporating plastic wastes into road pavement:
https://www.plasticstoday.com/building- ... good-thing