Scientists may have accidentally discovered a new engineered enzyme that can break down the massive amounts of plastic waste in the world’s oceans and landfills, leaving behind a new feedstock that will eliminate the need for continuing fossil extraction to feed new plastics production.
If it works, the new research will be a rude awakening for fossil executives who are betting big on plastics and petrochemicals to create demand for their product, as electricity production and personal transportation rapidly electrify over the next decade and beyond. The study appeared earlier this week in the Proceedings of the National Academy of Sciences.
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“The enzyme is able to digest PET (polyethylene terephthalate)—the same material used in the ubiquitous plastic bottle that’s clogging up landfills, coastlines, and oceans around the world,” EcoWatch reports. “The modified enzyme, called PETase, can break down PET in just a few days—a stunning discovery that could help fight the world’s escalating plastic crisis.”
The process works “works by reversing the manufacturing process by reducing polyesters back to their building blocks so [they] can be used again,” EcoWatch explains, citing a BBC report.
That means the modified enzymes “could be used to make more plastic, and that would avoid using any more oil,” said study co-author John McGeehan of the University of Portsmouth in the United Kingdom. “Then, basically, we’d close the loop. We’d actually have proper recycling.”
The potentially groundbreaking discovery happened by chance, when researchers from Portsmouth and the U.S. National Renewable Energy Laboratory (NREL) were studying a naturally-occurring enzyme, Ideonella sakaiensis, that was identified in 2016 at a waste recycling centre in Japan. That enzyme could break down PET, but over a longer period of time.
The researchers added some amino acids to the original enzyme in the hope of better understanding how it had evolved. “Surprisingly, we found that the PETase mutant outperforms the wild-type PETase in degrading PET,” said NREL materials scientist Nic Rorrer. “Serendipity often plays a significant role in fundamental scientific research,” McGeehan added, “and our discovery here is no exception.”
The results were powerful. “After just 96 hours, you can see clearly via electron microscopy that the PETase is degrading PET,” said NREL structural biologist Bryon Donohoe. “And this test is using real examples of what is found in the oceans and landfills.”
