Scientists accidentally create plastic-eating enzyme

Tests showed that the lab-made mutant enzyme had a supercharged ability to break down PET, one of the most popular forms of plastic used by the food and drinks industry.

Bottles made from PET are used to package 70% of soft drinks, fruit juices and mineral waters, according to the British Plastics Federation.

PET persists for hundreds of years in the environment before it degrades and the discovery may mean that significantly more plastic waste could be recycled.

Scientists accidentally create plastic-eating enzyme
Scientists accidentally create plastic-eating enzyme

:: People ‘sleepwalking’ over single-use plastic bottles

The new research sprang from the discovery of bacteria in a Japanese waste recycling centre that had evolved the ability to feed on plastic.

The bugs used a natural enzyme called PETase to digest PET bottles and containers.

Scientists have engineered an enzyme which can digest polyethylene terephthalate (PET), the plastic used in plastic bottles and other common packaging. - Diamond Light Source
Image:Electron microscope photos of enzyme/substrate interactions. Pic: Dennis Schroeder / NRE

While analysing the molecular structure of PETase, scientists at the University of Portsmouth accidentally created a powerful new version of the protein.

Working with the US Department of Energy’s National Renewable Energy Laboratory (NREL), the scientists subjected PETase to intense X-ray beams at the Diamond Light Source synchrotron facility in Harwell, Oxfordshire.

X-rays 10 billion times brighter than the sun are generated at the facility by accelerating electrons around a circular tunnel.

The X-rays can be used to reveal the fine structure of materials and biomolecules, down to the level of individual atoms.

Using the PETase blueprint provided by the Diamond Light Sources, the scientists re-engineered an active region of the molecule.

The result was a mutant protein with an enhanced ability to attack plastic.

It could also attack another form of plastic, polyethylene furandicarboxylate (PEF), a bio-based substitute for PET plastics that is being hailed as a replacement for glass beer bottles.

“Serendipity often plays a significant role in fundamental scientific research and our discovery here is no exception,” said Professor John McGeehan, director of the Institute of Biological and Biomedical Sciences at Portsmouth University.

More from Ocean Rescue

  • People ‘sleepwalking’ over single-use plastic bottles

  • Battle against plastic in world’s oceans gets £61.4m war chest

  • Whale killed by 29kg of human rubbish in stomach

  • Plastic doesn’t reduce food waste, study finds

  • Drastic drop in plastic bags found in sea following 5p charge

  • ‘Cesspool’ paradise island of Boracay to shut in the Philippines

“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.”

:: Sky’s Ocean Rescue campaign encourages people to reduce their single-use plastics. You can find out more about the campaign and how to get involved at

Similar Posts