Breaking: Scientists Engineer Fusion Enzyme That Boosts Polyester Recycling

PET (polyethylene terephthalate) is valued for being cheap and durable, but these traits also lead to massive plastic waste accumulation. Polyester textiles are especially hard to recycle due to their dense, highly ordered fiber structure, which resists biological degradation.

The team created a fusion enzyme by combining two components: a heat-stable cutinase (which naturally breaks down cutin, a plant-surface polyester) and a binding module that helps the enzyme attach more firmly to plastic. Both parts were matched to work optimally at the same temperature and on similar plastic structures.

While the modified enzyme bonded more strongly to highly crystalline PET—the tough, compact form found in many plastics—this did not always speed up breakdown. Significant gains occurred only when the plastic was less crystalline and more accessible. Under controlled, industry-mimicking conditions (20% plastic by weight, carefully managed pH), the fused enzyme broke down disordered PET much faster.

The best result came from a pre-consumer polyester textile that had been treated to reduce its crystallinity and finely ground: the yield of useful breakdown products doubled.

“By matching the enzyme with the right binding module and pre-treating the plastic appropriately, we can overcome a major recycling bottleneck,” said Professor Andrew Pickford, director of the University of Portsmouth's Centre for Enzyme Innovation. “It's not just about adhesion—it's about enabling an efficient chemical reaction at industrial plastic concentrations.”

The research also clarifies why earlier studies showed mixed results: overly tight enzyme binding can slow the reaction, a principle known in chemistry as the Sabatier principle. The team concludes that successful enzyme-based PET recycling depends on three factors—the enzyme, its guiding module, and the plastic's physical structure.

Source: Adapted from a news release by the University of Portsmouth via Newswise, April 6, 2026. The original release can be found on Newswise 

https://www.newswise.com/articles/plastic-eating-fusion-enzyme-improves-polyester-textile-recycling