Breaking up is hard to do.
That’s certainly true for common plastics like polyethylene terephthalate (PET). A water bottle made of a thin film of PET (perhaps half a millimeter thick) takes about 450 years to degrade. Along the way it will exist as microplastics, which are so pervasive they are even turning up in living people’s lung tissue, as we saw for the first time just a month ago. And even those kinds of numbers are guesstimates because many studies don’t last long enough to see any appreciable degradation of PET at all.
A lot of efforts to produce biodegradable and bioresorbable plastics are making good progress, and that’s great for the future, but what about the mountains of plastic that already exist and that we keep on generating? In the U.S., the landfill rate for discarded plastics is still about 75%! We have a lot of work to do.
Good thing Hal Alper’s chemical engineering lab at the University of Texas is on the job. In the April 27 issue of Nature, they report on an enzyme they developed called FAST-PETase. Designed with the help of artificial intelligence, it degrades untreated postconsumer PET not in centuries, but in days. And this can be done at temperatures of 50°C and below, where many types of bacteria can thrive. See where this is going?
Continue reading… “Waste plastic broken down not in centuries but in days by an AI-engineered enzyme”

