Accidentally-developed enzyme eats plastics

Researchers have developed an enzyme that can digest certain types of plastics bringing new hope to end a 'global crisis'.

According to a study by the Guardian newspaper, an astounding one million plastic bottles are sold each minute around the world. Only a small amount of these are recycled, leaving the rest to pile up in landfills and in the oceans. At Springwise, we have seen innovative ways of reducing the use of plastics, including dissolvable packaging and a squeezable water bottle made from titanium. Now, scientists at the University of Portsmouth have taken a step forward in plastic recycling engineering an enzyme which can digest polyethylene terephthalate (PET) plastics.

The research was the combined effort of teams at the University of Portsmouth and the US Department of Energy’s National Renewable Energy Laboratory. The researchers took as their starting point a bacterium discovered in 2016 in a Japanese waste dump. The bacterium had evolved naturally to digest plastic. While studying the enzyme, the team inadvertently created a molecule that was even better at breaking down the PET.

Team leader Professor John McGeehan, of the University of Portsmouth, described the improvement in the enzyme’s ability to digest plastic as “modest”. However, he also pointed out that this unexpected discovery suggests that “there is room to further improve these enzymes…”

Currently, PET plastics take hundreds of years to decompose, while the enzyme can begin to break down the plastic in just a few days. In addition, the new enzyme can also degrade polyethylene furandicarboxylate (PEF), a bio-based plastic used as a replacement for glass bottles. The team are hoping to develop a way to speed up the enzymatic action further and create a recycling process at scale. McGeehan suggests that the enzyme could in future be used to turn plastics back to their original components, which could then be used to make new plastic items. Will enzymes one day be able to eliminate the world’s mountain of plastic waste?