Two scientists have accidentally stumbled upon an organic enzyme that can eat some of our worst polluting plastics, providing a possible solution to what is arguably one of the world’s biggest environmental problems.
Polythylene terephthalate or PET is one of the worst man-made plastics for recycling taking hundreds of years to break down into the environment.
Yet despite this, the amount of waste plastic in the oceans could treble in the next 10 years unless urgent action is taken to curb the problem.
It’s estimated that a frankly staggering 12 million tonnes of plastic rubbish is dumped into the oceans every single year.
Professor John McGeehan and his team from the University of Portsmouth along with Dr Gregg Beckham from the US Department of Energy’s National Renewable lab had both been trying to find a way of combating this plastic pest when they stumbled on the solution.
The team had been looking originally at another enzyme called PETease which had evolved in a waste recycling centre in Japan. PETease was a remarkable organism, having come into existence only since PET was created in the 1940s.
To analyse PETease, the teams employed the Diamond Light Source in Oxfordshire. This ultra-powerful microscope is able to fire intense X-rays 10 billion times brighter than the Sun, giving the scientists the ability to examine the 3D atomic structure of the enzyme.
Upon inspecting the model the teams found it looked very similar to another enzyme known as a cutinase. To test their theory they then mutated the PETease to make it look even more like a cutinase.
It was then that the serendipitous moment happened. The team discovered that they had inadvertently made the enzyme better than its original form at digesting the plastic.
“Serendipity often plays a significant role in fundamental scientific research and our discovery here is no exception,” Professor McGeehan said.
The team will now work to improve the enzyme even further with Professor McGeehan confident that we could finally have a viable recycling solution for these plastics within just a few years.
Professor McGeehan said: “The engineering process is much the same as for enzymes currently being used in bio-washing detergents and in the manufacture of biofuels – 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 substrates like PEF, PLA and PBS, back into their original building blocks so they can be sustainably sustained.”