Plastic-eating enzyme could help fight pollution, scientists say

Theresa May is expected to launch a multi-million-pound bid to help rid the oceans of plastic pollution

Theresa May is expected to launch a multi-million-pound bid to help rid the oceans of plastic pollution

But in a new twist, British and American scientists have announced that while studying this bacteria, they accidentally created a mutant enzyme that's even more efficient at breaking down plastic bottles.

Researchers of the United States and Britain have accidentally engineered an enzyme that can digest plastics.

Another is the recently discovered enzyme that consumes PET plastics called PETase, which scientists at the University of Portsmouth and the US Department of Energy's National Renewable Energy Laboratory (NREL) used as a starting point for their groundbreaking research. PET can last hundreds of years in a natural environment.

PETase is thought to have evolved in a waste recycling centre in Japan, which allowed a bacterium to degrade plastic as a food source.

In collaboration with scientists at the Diamond Light Source in the UK, Professor McGeehan and Dr Gregg Beckham at NREL used a synchrotron that uses intense beams of X-rays, 10 billion times brighter than the sun, as a microscope powerful enough to see individual atoms.

"What actually turned out was we improved the enzyme, which was a bit of a shock", says lead researcher, John McGeehan from the University of Portsmouth, UK. A computer modeling of PETase showed that it resembles another enzyme found in fungus and bacteria, the cutinase. To test this theory, the researchers mutated the PETase and that was when the unexpected happened. Little of this is recycled, which means we are polluting our environment with materials that take centuries to degrade, much of which washes out into the ocean where it breaks into tiny pieces that are almost impossible to track, let alone clean up. Hidden in the soil at a plastics recycling plant, researchers unearthed a microbe that had evolved to eat the soda bottles dominating its habitat, after you and I throw them away.

"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", said Prof John McGeehan.

The engineered enzyme has the added benefit of being able to degrade polyethylene furandicarboxylate (PEF), a PET alternative that has been floated as a replacement for glass beer bottles.

"It is a modest improvement - 20% better - but that is not the point", said McGeehan. The structure of PET is too crystalline to be easily broken down and while PET can be recycled, most of it is not. "It gives us scope to use all the technology used in other enzyme development for years and years and make a super-fast enzyme".

The discovery could be a step toward eliminating the huge swaths of plastic waste often found floating in oceans or washed up on beaches all over the world, the researchers said.

Scientists have created a mutant enzyme that breaks down plastic drinks bottles made from polyethylene terephthalate (PET), and they did it completely by accident.

The team behind the research at Portsmouth University includes PhD students and even undergraduates, and when I visited their lab their excitement was infectious.

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