A new enzyme cocktail that accelerates the degradation of plastics offers a step forward in the search for a new form of recycling that is faster, more cost-effective and works on a larger scale than current methods, the British and American researchers said this week. .
The “superenzyme” could be used to break down plastic bottles much faster than current recycling methods and create the raw material to create new ones, according to the scientists. And it could make it easier to reuse the material.
“This is a very interesting development for plastic recycling and environmental protection,”
It is estimated that 359 million tons of plastic are produced every year worldwide, of which at least 150 million are in landfills or in the environment.
Once valued for their durability, plastics can take up to 450 years to degrade in the ocean if they do, according to National Oceanic and Atmospheric Administration. Much of it breaks down into tiny fragments known as microplastics that have been found in marine life, ocean water, and the guts of humans.
Researchers are increasingly looking for solutions, including biodegradable plastics.
As the world faces climate change and the need to burn far less fossil fuels, oil and gas companies looking for alternatives for oversupply are turning to manufacturing more plastics such as PET, one of the most popular plastics. in the world. It is found in soda bottles, synthetic clothing, and packaging.
The study, published Monday in the journal PNAS by a team of scientists from the University of Portsmouth and the National Renewable Energy Laboratory and other US institutions, focuses on a combination of two enzymes derived from a bacterium discovered in Japan in 2016. scientists found that this bacterium could break down PET.
In 2018, the team was successful breaking down plastic using one of two enzymes. But when the second enzyme is added, the students found that the process works six times faster.
“We take back the original building blocks,” explained Prof. John McGeehan, director of the Center for Enzyme Innovation and co-leader of the team. And these building blocks can be reused again.
These scientists are not alone in the race to find a faster and cheaper way to break down plastic.
In a major breakthrough earlier this year, researchers from the Toulouse Institute of Sciences and Carbios, a French bioindustrial company, published the results in Nature of another enzyme that degraded PET within 10 hours. Alain Marty, scientific director of Carbios, he said his company’s process was more efficient for “endless PET recycling” and was already in a “pilot industrial phase”.
The process developed by Mr. McGeehan’s team is slower – recycling a plastic bottle could still take days or weeks. They are now exploring plastic softening and other alternatives to reduce degradation time to a few hours. They also hope to scale up their operations.
Since the publication of the study, GlaxoSmithKline, a British pharmaceutical company, has offered the team the use of fermenters at a nearby penicillin manufacturing facility.
Even with the breakthroughs in recycling, a problem remains: how to get plastics to recycling plants in the first place. Experts said that much of the obstacle to recycling PET and other plastic waste lies in ocean recovery and responsible waste management.
“We created this problem in the first place,” McGeehan said.
However, he said, it’s nice that nature may have provided a solution.