The newly discovered mutant enzyme recovers the plastic bottle within a few hours and has a full strength level

Bacterial enzymes found in compost may lead to faster and more efficient recycling of plastic bottles.

Plastic waste is a major environmental problem. About 200 million tons of plastic waste are accumulated in landfills or the natural environment every year. An important reason for this problem is polyethylene terephthalate (PET), which is widely used in the manufacture of plastic bottles and is not easy to recycle. Only 30% of the plastic in the bottle is recycled into new plastic, and it usually ends up as poor quality plastic.

Now, researchers from Carbios report that they have found a way to convert 90% of plastic back to full strength plastic for reuse. These researchers have created a mutant enzyme that can break down plastic within hours.

Their findings were published in the "Nature" magazine on Wednesday.

High quality new bottle

Carbios researchers collaborated with Pepsi and L'Oréal on this project, using this enzyme to reduce plastic bottles into chemical building blocks, which are then used to make new high-quality plastic bottles. In other words, this is real recycling. Current recycling technology can usually only reuse this plastic to make carpets or clothes.

The team hopes to increase its recycling methods to an industrial scale within five years.

The enzyme discovered by the researchers was found in the leaves of compost. In fact, this usage has long been forgotten. Carbios Chief Scientific Officer, Professor Alain Marty of the University of Toulouse, France, said: "It has been completely forgotten, but it turns out to be the best."

The research team introduced mutations into the enzyme, which can break down the PET plastic made into beverage bottles. The researchers then used the enzyme to break down a ton of waste plastic bottles, all of which degraded by 90% within 10 hours. Since then, the team has used decomposed materials to make food-grade plastic bottles.

Martin Stephan, deputy chief executive of Carbios, said: "We are the first company to bring this technology to market. Our goal is to be put into operation on a large-scale industrial scale by 2024 and 2025."