Before the yeast can start feasting, the PET plastics are subjected to a process called oxidative hydrothermal dissolution to break them down into smaller bits that the microbes can digest.
Sensationalism aside, this could actually be a big deal. We use a lot of PET (polyethylene). Plastic drink bottles, plastic bags, plastic wrap, tape, fabrics, even some car parts. PET is a huge market segment of consumer products that are difficult to replace with environmentally friendly alternatives.
If we can boil it and then feed it to a vat of yeast to break down, that would be fantastic. Even better, it could remove some of the difficulty of plastic sorting which is a major part of the recycling problem. Basically, if you dump some plastic into the vat that the yeast can't eat, well it just won't eat it, so just sift it out of the vat later for a different disposal process, no big deal.
Even if humans can't directly consume the byproduct, I'm sure we can use it for something else.
My biggest question is how long this takes, which they don't address in the article. How long do you have to boil the material (how much energy, how much water, how much oxygen, how big a facility to process X volume of waste), and how long does it take the yeast to break it down? If it can be done in hours or days that's well worth spending some resources to build a processing center. If it takes months or years it will require more planning and analysis.
top 89 comments