Scientists investigating a naturally occuring bacterium have accidentally created a new enzyme that can digest plastic bottles.
The breakthrough has the potential to solve the global plastic pollution crisis by enabling a full recycling process of plastic bottles and packaging, according to researchers.
A bacterium that naturally evolved to eat plastic was first discovered in 2016 at a waste dump in Japan, but now researchers have revealed the detailed structure of the crucial enzyme produced by the bug.
Researchers from the University of Portsmouth and the US Department of Energy’s National Renewable Energy Laboratory studied the enzyme to see how it evolved, only for tests to show they had inadvertently made the molecule even better at breaking down the polyethylene terephthalate (PET) plastic used for single-use plastic bottles and other common types of packaging.
“What actually turned out was we improved the enzyme,” said Professor John McGeehan, professor of Structural Biology and co-director of the Institute of Biomedical & Bimolecular Science at the University of Portsmouth, who led the research. “It’s great and a real finding.”
The enzyme takes a few days to begin breaking down the plastic, and researchers are optimistic this can be speeded up even further and become a viable large-scale process. It also has the potential to recycle clear plastic bottles back into clear plastic, which could hugely reduce the need to produce new bottles.
“What we are hoping to do is use this enzyme to turn this plastic back into its original components, so we can literally recycle it back to plastic,” added McGeehan. “It means we won’t need to dig up any more oil and, fundamentally, it should reduce the amount of plastic in the environment. Although the improvement is modest, this unanticipated discovery suggests that there is room to further improve these enzymes, moving us closer to a recycling solution for the ever-growing mountain of discarded plastics.”
A Friends of the Earth Europe spokesman said: “This is a step forward on plastic recycling,” and urged researchers, government and the retail and packaging industries to work together to boost recycling levels and continue creating innovative materials that are safe for the environment.
Laura Winningham, CEO of hunger relief charity City Harvest London, called the discovery a “truly exciting development,” adding that the enzyme could “complement [the charity’s] work and make a tremendous environmental difference.”
The discovery follows research published by BRITA UK and environmental charity Keep Britain Tidy today (17 April), which found that only 17% of consumers are strongly committed to finding alternatives to single-use plastic bottles.