Plastic-eating bacteria created by accident
A PLASTIC-EATING protein grown in a British laboratory could revolutionise recycling and prevent thousands of tons of non-biodegradable waste clogging up landfill sites and the oceans.
The enzyme, created by accident by researchers from Portsmouth University, is the first known protein capable of digesting polyethylene, one of the most commonly used plastics for consumer goods.
The breakthrough was made when tests were conducted on a naturally occurring bacteria found in a Japanese recycling centre, with the X-ray experiments causing it to mutate into a more powerful enzyme. Tests showed the lab-made mutant had a supercharged ability to break down polyethylene terephthalate (PET), one of the most popular forms of plastic employed by the food and drinks industry.
Bottles made from PET are used to package 70 per cent of soft drinks, fruit juices and mineral waters sold in shops and supermarkets, according to the British Plastics Federation. Although it is said to be highly recyclable, discarded PET persists for hundreds of years before it degrades.
The research sprang from the discovery that bacteria in a Japanese waste recycling centre had evolved the ability to feed on plastic, using a natural enzyme called Petase to digest bottles and containers. It was while probing the bacteria’s molecular structure that the British team inadvertently created a powerful new version.
Prof John Mcgeehan, the project’s lead scientist at the University of Portsmouth, said: “Serendipity often plays a significant role in fundamental scientific research, and our discovery here is no exception. 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.
“The technology exists and it’s well within the possibility that in the coming years we will see an industrially viable process to turn PET and potentially other (plastic) substrates back to their original building blocks, so that they can be sustainably recycled.”
Working with US colleagues, the Portsmouth scientists subjected the bacteria to intense X-ray beams at the Diamond Light Source synchrotron facility in Harwell, Oxfordshire.
Prof Mcgeehan, director of the Institute of Biological and Biomedical Sciences at Portsmouth, added: “The scientific community who ultimately created these ‘wonder-materials’ must now use all the technology at their disposal to develop real solutions.”
The findings are reported in the journal Proceedings of the National Academy of Sciences.