Enzyme that eats plastic could make recycled PET cheaper than new plastic

A team led by the US Department of Energy's National Renewable Energy Laboratory (NREL) and the University of Portsmouth's Centre for Enzyme Innovation reported a major step toward economically viable plastic recycling. Published in Nature Chemical Engineering on June 30, 2025, the work describes an enzymatic process that breaks down PET, the plastic used in drink bottles and polyester fibers, far more cheaply and cleanly than before.

The numbers are striking. Compared with earlier enzymatic methods, the new process reduces operating costs by 74%, greenhouse gas emissions by nearly 50%, and energy use by 65%. A key innovation is replacing sodium hydroxide with ammonium hydroxide, which can be regenerated in-process through thermolysis to create a closed-loop system. That change cuts expensive acid and base additions by more than 99%.

“Published in Nature Chemical Engineering on June 30, 2025, the work describes an enzymatic process that breaks down PET, the plastic used in drink bottles and polyester fibers, far more cheaply and cleanly than before.”

Crucially, the recycled PET reaches a minimum selling price of $1.51 per kilogram, undercutting virgin PET produced from fossil fuels at $1.87 per kilogram. If that holds at scale, recycled plastic could finally compete on price rather than relying on regulation or goodwill, a long-standing barrier to circular plastics. The research drew on collaborators including Professor Andrew Pickford and Professor John McGeehan, whose earlier work on enzyme engineering helped launch the field, alongside Dr Gregg Beckham at NREL.

The honest caveat is that the process has not yet been deployed at industrial scale, and lab economics do not always survive the jump to full commercial plants. Real-world feedstocks are dirty and mixed, and building new infrastructure takes years. Still, the researchers are optimistic, and the result suggests that one of the most stubborn problems in plastic pollution, the cost gap between recycled and new material, may be closing. With billions of tons of PET in circulation, even a partial shift toward enzyme-driven recycling could keep enormous volumes of plastic out of landfills and oceans.