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NATURESCIENCE

Create an enzyme that degrades plastic

When we talk about the struggle to take care of the environment, most people think of news about global warming, the ozone layer, rising ocean temperatures or natural disasters. But in addition to all these problems, there are others that are less visible but equally worrying. One of these environmental problems is plastic.

Many scientists today are studying ways to eliminate the problem of plastic on our planet. Every year thousands of tons of these wastes are thrown away. They end up flooding many areas of the earth, as well as our seas and oceans. There are more and more images of entire plastic islands floating in the sea. Kilometers of garbage that contaminate our waters and kill thousands of marine animals.

ocean full of plastic

One of those investigations seems to have found the solution to fight plastic. If their studies are finalized, their progress could be used to gradually dispose of these highly polluting wastes.

Enzymes that degrade plastic

The research has been conducted jointly by scientists from Portsmouth University in the United Kingdom and the National Renewable Energy Laboratory of the U.S. Department of Energy. Its conclusions have been published in the prestigious scientific journal of the National Academy of Sciences of the United States.

The team has managed to design an enzyme capable of digesting or degrading some types of plastics. Among them are the most contaminants such as PET or Polyethylene Terephthalate. This type of plastic is characterized by its very slow degradation. Being able to stay in the environment for hundreds of years. PET is used in the production of virtually all the plastic bottles we consume.

mutant enzyme that degrades plastic

Scientists were studying the structure of a natural enzyme called PETase, produced by the bacterium Ideonella sakaiensis. This enzyme originated in a waste center in Japan and was able to degrade plastic. In order to study the enzyme in as much detail as possible, they used X-ray beams 10 billion times brighter than the sun. In this way they obtained a high resolution 3D model of the enzyme.

During the study of the enzyme’s crystalline structure, the team accidentally designed an improved enzyme. It was able to degrade plastic more efficiently than its natural counterpart. For researchers the goal now is how to get the enzyme to be used massively. To put an end to the plastics that populate the planet. Not in vain is PET a current problem against which there are no effective solutions, since only a tiny part of the product is recycled.

Towards industrial use

The researchers were assisted by a computational modeling of the University of South Florida. They thus warned that PETase was very similar to another enzyme known as cutinase, which is found in fungi and bacteria. Scientists conducted experiments mutating PETase to make it more like cutinase. The result was an enzyme that degraded PET more rapidly, but is also capable of degrading polyethylene furandicarboxylate or PEF.

mutant PETase enzyme that degrades plastic

One of the challenges now facing the team is the adaptation of the enzyme to industrial recycling processes. The process is said to be similar to those currently used in detergents for biowashing or in the manufacture of biofuels. So the team hopes in a couple of decades the processes have evolved for an effective reuse of the most polluting plastics available today, such as PET or to a lesser extent PEF.

Removing plastics from the Soil

PET first appeared in 1940. At that time it was a revolution in the industry. Because it radically changed the way thousands of products were packaged. But what no one expected was that this revolution would end up being one of the biggest problems for the environment after 100 years.

Hopefully, scientists around the world will continue to advance their studies against plastic. Hopefully on the centenary of the birth of PET, we will have enough tools to recycle it in a sustainable way. And let’s see our seas and oceans free of those masses of floating plastic. Our marine species will appreciate it.

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