Enzyme that eats PET plastic

There could be whole books dedicated to scientific discoveries made by accident. Viagra, for example, the subject of millions of spam emails every day, was found while Pfizer were testing heart drugs. Researchers noticed a strange side-effect apparent in rats given a batch of heart drugs and the next thing you know lives are being changed by little blue pills.

In what is an incredibly timely discovery, two scientists have accidentally found an organic enzyme that can eat some forms of plastic, providing a possible solution to what is arguably one of the world’s biggest environmental problems – plastic pollution.

Polythylene terephthalate or PET is one of the worst culprits, taking hundreds of years to break down naturally into the environment, and the amount of waste plastic in the oceans could treble in the next 10 years unless urgent action is taken to curb the problem, with an estimated 12 million tonnes of plastic rubbish dumped into oceans every year.

With this in mind, Professor John McGeehan and his team from the University of Portsmouth and Dr Gregg Beckham from the US Department of Energy’s National Renewable lab had been trying to find a way of combating this plastic pest when they discovered the enzyme. They were originally looking at an enzyme called PETease which had evolved in a waste recycling centre in Japan. In itself a remarkable organism, PETease only came into existence after PET was created in the 1940s.

However, when the teams looked at PETease carefully, they realised it looked very similar to another enzyme known as a cutinase. To test their suspicions, they mutated the PETease to make it look even more like a cutinase. It was then they discovered that by mutating PETease they had made it better than its original form at digesting the plastic.

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.”

Good news then.

Rachele Moltrasio

La bella strega

The spelling Rachele might tell you I'm not British, but Italian by birth. I've lived in the UK for 18 of my 37 years, first as a child and then again for the past couple of years. I'd say I'm probably more British than Italian until you annoy me.

I've spent most of my life working in design, one way or another, including working for the most famous name in writing pens in Europe. But alongside my work, I've always had a passion for writing and languages. Life's not perfect, but it brings us goodish times....