Researchers at the University of Portsmouth and the U.S. Department of Energy’s National Renewable Energy Lab (NREL) have unwittingly engineered a mutant enzyme that can super-charge the breakdown of PET plastic – the plastic you find in everyday plastic bottles. The research was published in the Proceedings of the National Academy of Sciences (PNAS) and reported on Phys.org.
Dr. John McGeehan at the University of Portsmouth and Dr. Gregg Beckham were studying the structure of PETase, an enzyme found in 2016 in bacteria in a waste recycling center in Japan. This bacterium had naturally evolved to slowly digest PET plastic.
To better understand how PETase works, the team utilized intense X-ray beams that are 10-billion times brighter than the sun to see individual atoms. They did some tweaking of the enzyme to better understand its structure during their research, which resulted in the mutation.
The unintended result? They inadvertently engineered an enzyme that is much faster at degrading plastic than the one that was discovered in Japan.
“It’s incredible because it tells us that the enzyme is not yet optimized,” said Dr. McGeehan, in an article by science writer Damian Carrington in the Guardian. “It gives us scope to use all the technology used in other enzyme development for years and years to make a super-fast enzyme.”
We Need to Get a Handle on Our Plastic Consumption
Humans consume 50 billion plastic water bottles every year; 30 million of which are consumed by Americans. And plastic bottles and bags are the most prevalent form of pollution found on our beaches and in our oceans.
Every square mile of the ocean has over 46,000 pieces of plastic floating in it. (Source: Ocean Conservatory via the Huffington Post.)
Yet, we only recycle about 28% of the PET plastic we use. This recycled PET is generally used in different products than what is was originally used for, such as clothing, carpets, and even dog collars, flip flops, and sunglasses. Utilizing enzymes, plastic can be recycled back into its near “virgin” form, which means it can be used again to create similar products, reducing the need to create new plastic from fossil fuels, and not to mention – giving us even more reason to recycle it.