NREL researchers Chris Johnson and Rita Clare take biological samples from an old PET soda bottle that Johnson found during a cleanup drive around NREL. They are looking to isolate any microbes that may be breaking down the PET. Photo by Dennis Schroeder, NREL
Golden, CO, Oct. 01, 2020 (GLOBE NEWSWIRE) — A collaboration between scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), the University of Portsmouth in the United Kingdom, and other partners has yielded further insight into the workings of plastic-eating enzymes.
The research determined two synergistic enzymes—PETase and MHETase—work effectively in tandem to break down polyethylene terephthalate (PET), which is a type of plastic used to make single-use beverage bottles, clothing, and carpeting. The research follows an earlier collaboration between these partners focused on PETase.
A bacterium, Ideonella sakaiensis 201-F6, was discovered in the soil outside of a Japanese PET bottle recycling plant in 2016 and was shown to secrete both PETase and MHETase. Researchers at NREL and Portsmouth were able to engineer PETase to increase its ability to digest PET, although still not fast enough to make the process commercially viable to handle the tons of discarded bottles littering the planet.
Gregg Beckham, a senior research fellow at NREL and co-lead of a new paper outlining the latest findings, said MHETase and PETase degrade PET faster than PETase alone. “They are better together than they are separate. PETase conducts the initial breakdown of the PET polymer, and MHETase further deconstructs the soluble products of PETase to produce the