Scientists Just Discovered Plastic-Eating Bacteria That Can Break Down PET
Now a team at Kyoto University has, by rummaging around in piles of waste, found a plastic munching microbe. After five years of searching through 250 samples, they isolated a bacteria that could live on poly(ethylene terephthalate) (PET), a common plastic used in bottles and clothing. They named the new species of bacteria Ideonella sakaiensis.
You may think this is the rerun of an old story, as plastic-eating microbes have already been touted as saviours of the planet. But there are several important differences here.
First, previous reports were of tricky-to-cultivate fungi, where in this case the microbe is easily grown. The researchers more or less left the PET in a warm jar with the bacterial culture and some other nutrients, and a few weeks later all the plastic was gone.
Bottle breakdown. Illustration: P. Huey. Reprinted with permission from U.T. Bornscheuer, Science 351:1154 (2016)
Second - and the real innovation - is that the team has identified the enzymes that Ideonella sakaiensis uses to breakdown the PET. All living things contain enzymes that they use to speed up necessary chemical reactions. Some enzymes help digest our food, dismantling it into useful building blocks. Without the necessary enzymes the body can’t access certain sources of food.
The enzyme that the bacteria uses has been named PETase. Just as the Amylase in our saliva breaks down carbohydrates, PETase breaks down PET. It would be very similar to a hard-boiled sweet melting in your mouth, except... ya know, spitting on a wall.
I'm not sure how you would get the salivary glands to produce PETase aswell as Amylase though. Maybe through a process similar to the one used to genetically modify bacteria to produce Insulin?
If this hypothetical chewing gum had the ability to genetically modify some (not all! You still want SOME amylase for eating purposes!) of the cells in the salivary glands, then it could be possible to have them produce PETase.
NOTE: On the subject of sweets melting in the mouth, it would take just as long to melt through your walls. Unless you want to stand licking a wall for hours (and accidentally ingesting small amounts plastic), it will not be a feasible choice. However, thanks to imagination and suspension of disbelief, anything can happen in a book! Maybe this is "Super Awesome PETase which melts through plastic in seconds!" and you spread it in the outline of a door and bust through?