A breakthrough that builds on plastic-eating PETase enzymes could be used to clear landfills (Credit: Nick Fewings on Unsplash)
Hope.
Created by researchers at the University of Texas at Austin, a new enzyme variant is poised to usher in a new era of plastic recycling—by eating the plastic. The tailor-made enzyme can break down materials that typically take centuries to degrade in just a matter of days. This huge acceleration in timescale could allow major waste-producing industries to reduce their environmental impact by reusing plastics at the molecular level.
The study focused on PET since it’s found in most consumer packaging and makes up 12% of all global waste. In trials, the enzyme was able to complete the full circular process of depolymerization—breaking down the plastic into monomers—and repolymerization—reassembling it. In some cases, the plastics could be fully broken down in as little as 24 hours.
A machine learning model was used to generate novel mutations to a natural enzyme called PETase and predict which mutations would result in enzymes that could most rapidly depolymerize post-consumer waste plastics at low temperatures. Researchers have named the resulting enzyme FAST-PETase, or functional, active, stable, and tolerant PETase.
Currently, only about 10% of post-consumer plastics are recycled. Other disposal methods—burning, glycolysis, and pyrolysis among them—are energy-intensive and produce noxious waste. Biological solutions take much less energy, and FAST-PETase is the first to operate efficiently at low temperatures—less than 50 degrees Celsius—while being both portable and affordable at industrial scales.
The team plans to continue work on scaling up enzyme production to prepare for industrial and environmental applications and has filed a patent for the technology. Potential uses include cleaning up landfills and high waste-producing industries, as well as possible uses in environmental remediation. Since the enzyme can work at ambient temperature, it has a huge advantage when operating in environmental cleanup applications. Full research and findings on the enzyme were recently published in Nature.
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