Scientists develop plastic-eating enzyme

Scientists have accidentally engineered an enzyme that can digest some of the most common plastics littering the environment, providing a potentially ground-breaking recycling solution.

Led by teams at the University of Portsmouth and the US Department of Energy’s National Renewable Energy Laboratory (NREL), the researchers initially hoped to study the structure of the natural plastic-eating enzyme PETase.

However, they instead inadvertently engineered an enzyme that is better at degrading plastic than the one that evolved in nature, with work now being done to introduce an industrial-scale roll-out.

“Serendipity often plays a significant role in fundamental scientific research and our discovery here is no exception,” professor John McGeehan from the University of Portsmouth, said.

“We can all play a significant part in dealing with the plastic problem, but the scientific community who ultimately created these ‘wonder-materials’, must now use all the technology at their disposal to develop real solutions.”

The mutant enzyme decomposes polyethylene terephthalate (PET), which persists in the environment for hundreds of years, but has not existed in nature for very long.

Significantly, the enzyme can also degrade polyethylene furandicarboxylate, a bio-based substitute for PET plastics that is being hailed as a replacement for glass beer bottles.

The discovery was made possible after collaboration with scientists at the UK’s Diamond Light Source, where x-ray beams 10 billion times brighter than the sun were used as a microscope powerful enough to see individual atoms.

The researchers now intend to apply the tools of protein engineering and evolution to create an enzyme that can break down plastics in a fraction of the time.

“Few could have predicted that since plastics became popular in the 1960s huge plastic waste patches would be found floating in oceans, or washed up on once pristine beaches all over the world,” McGeehan said.

“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.”

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