Scientists Have Created an Enzyme that Breaks Down Plastic, by Accident

Eventually, it can help solve the growing problem of contamination by this material.

Scientists from the United Kingdom and the United States redesigned an enzyme that ‘eats’ plastic and could in the future help alleviate pollution: the eight million tons of this material that is dumped into the oceans every year.

The enzyme is capable of digesting polyethylene terephthalate, or PET, a type of plastic patented in the 1940s and now used in millions of tons of packaging. PET can persist for hundreds of years in the environment and currently pollutes large areas of land and sea around the world.

Experts from the University of Portsmouth in the United Kingdom and the National Renewable Energy Laboratory of the US Department of Energy made the discovery while examining the structure of a natural enzyme thought to have evolved in a waste recycling centre in Japan.

Upon discovering that this enzyme was helping a bacterium to break down, or digest, PET, the researchers decided to “tweak” its structure by adding some amino acids, said John McGeehan, a professor at Portsmouth and co-director of the work. This led to a fortuitous change in the performance of the enzyme that allowed its ability to eat plastic faster.

The enzyme takes a few days to start breaking down the plastic, much faster than the centuries it takes in the oceans. But researchers are optimistic that this can be accelerated further and become a viable process on a large scale.

“What we hope to do is use this enzyme to convert this plastic back into its original components, so that we can literally recycle it into plastic,” McGeehan said. “It means that we will not need to dig up more oil and, fundamentally, it should reduce the amount of plastic in the environment.”

Currently, even those bottles that are recycled can only become fibres for the manufacture of clothes or carpets. The new enzyme would allow re-making transparent plastic bottles, which could reduce the need to produce new plastic.

If the consumption of bags continues as it is today, soon, in the seas there will be more plastic than fish

“You always face the fact that oil is cheap, so virgin PET is cheap,” McGeehan said. “It’s very easy for manufacturers to generate more of those things, instead of trying to recycle, but I think there’s a public driver here: the perception is changing so much that companies are starting to see how they can recycle them properly.


Source: El Tiempo