PubMed · 2026-05-09
A new review finds that enzyme-based plastic recycling works well only for a narrow class of plastics with chemically breakable backbones, while the most common plastics — polyolefins like polyethylene and polypropylene — largely resist enzymatic attack. Real-world implementation faces major hurdles that lab results consistently obscure, and even optimistic scenarios place it as a limited contributor to plastic circularity by 2040.
Enzymatic depolymerization only achieves genuine chain-breaking on plastics with hydrolyzable backbones (e.g., PET); dominant polyolefins show only surface oxidation, not verified molecular breakdown.
Optimized enzymatic recycling of hydrolyzable plastics could reach $1.1–1.8/kg under favorable conditions, but polyolefins require costly hybrid chemo-enzymatic pretreatment strategies.
AI/ML-guided enzyme engineering has meaningfully improved performance on susceptible plastics, but those gains consistently trade off against enzyme stability, specificity, and manufacturing cost.