Enzymatic Recycling: Breaking PET Down to Build It Back Up

Innovation 6 April 2026 · 4 min read

What if plastic could be recycled infinitely, with no loss of quality? That is the promise of enzymatic depolymerisation — a biological approach to breaking down PET (polyethylene terephthalate), the plastic used in drinks bottles, food trays, clothing, and cosmetics packaging, back into its original monomer building blocks. The resulting monomers are chemically identical to those derived from petroleum, meaning they can be used to produce virgin-quality, food-grade PET in a true closed loop.

How it works

Enzymatic depolymerisation uses specialised enzymes — typically engineered variants of cutinase, a naturally occurring enzyme that breaks down cutin in plant cell walls — to cleave the ester bonds in PET polymer chains. The PET is broken down into its two constituent monomers: terephthalic acid (TPA) and monoethylene glycol (MEG). These monomers are then purified and repolymerised into new PET.

The process operates at relatively low temperatures (approximately 65–72°C) compared to chemical recycling methods that require temperatures of 200–300°C or higher. This lower energy requirement is a significant advantage. Crucially, the enzymatic process can handle coloured, multi-layer, and contaminated PET that mechanical recycling cannot process effectively — including food trays, cosmetics packaging, and polyester textiles.

Carbios: the leading player

French biotechnology company Carbios is the clear leader in enzymatic PET recycling. Key milestones include:

  • 2021: Opened an industrial demonstration plant with a PET depolymerisation reactor processing two tonnes per batch
  • April 2024: Broke ground on the world’s first commercial-scale enzymatic PET recycling plant in Longlaville, France. Planned capacity: 50,000 tonnes of prepared PET waste per year
  • 2024: Published peer-reviewed research demonstrating that their C-ZYME enzyme achieves best-in-class performance under industrial conditions, as confirmed by independent researchers at the University of Greifswald and Helmholtz-Zentrum Berlin
  • 2024: Signed MoU with Landbell Group for sourcing post-consumer PET waste for the Longlaville plant
  • 2025: Announced partnership with Zhink Group to build a second plant in China with minimum 50,000-tonne annual capacity
  • Early 2025: Announced 6–9 month construction delay at Longlaville while securing financing. Appointed new transitional CEO

Carbios has brand partnerships with L’Oréal, Nestlé Waters, PepsiCo, and Suntory, all of whom have committed to using enzymatically recycled PET. The company’s calculations suggest that widespread adoption of the technology could save the equivalent of 130 billion barrels of oil over 35 years.

Other players

  • Samsara Eco (Australia): Developing enzymatic recycling for PET and other plastics. Backed by Woolworths Group and Main Sequence Ventures.
  • NREL (US National Renewable Energy Laboratory): Published breakthrough research on engineered PETase enzymes. Open-source approach to enzyme development.
  • Leipzig University (Germany): Discovered PHL7 enzyme that degrades PET at record speed — faster than Carbios’ original enzyme variant. Published in Nature Communications.

Implications for packaging

For the UK packaging industry, enzymatic recycling could transform the economics of PET packaging. Currently, PET food trays (particularly multi-layer and coloured variants) are among the most problematic packaging formats under RAM, often receiving Amber or Red ratings due to difficulties in mechanical reprocessing. If enzymatic recycling becomes commercially available and is recognised within the UK’s RAM and pEPR frameworks, these formats could potentially achieve improved ratings.

However, this is not yet the case. Businesses should not rely on enzymatic recycling to justify maintaining difficult-to-recycle PET formats today. The technology is still scaling, the Longlaville plant has experienced delays, and there is no UK-based enzymatic recycling facility currently operational or planned. For now, designing PET packaging for mechanical recyclability remains the most effective strategy for reducing pEPR fees.

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