Mixed plastics waste valorization through tandem chemical oxidation and biological funneling

TLDR

Mixed plastics waste is an abundant, largely untapped feedstock for valuable products, yet its chemical diversity and complexity pose major barriers to utilization. The study demonstrates that metal‑catalyzed autoxidation depolymerizes comingled polymers into oxygenated small molecules suitable for biological conversion. We combine this autoxidation with engineered Pseudomonas putida that funnels the resulting oxygenated compounds into a single product, such as β‑ketoadipate or polyhydroxyalkanoates. This hybrid process establishes a selective route to convert mixed plastics waste into useful chemical products.

Abstract

Mixed plastics waste represents an abundant and largely untapped feedstock for the production of valuable products. The chemical diversity and complexity of these materials, however, present major barriers to realizing this opportunity. In this work, we show that metal-catalyzed autoxidation depolymerizes comingled polymers into a mixture of oxygenated small molecules that are advantaged substrates for biological conversion. We engineer a robust soil bacterium, Pseudomonas putida, to funnel these oxygenated compounds into a single exemplary chemical product, either β-ketoadipate or polyhydroxyalkanoates. This hybrid process establishes a strategy for the selective conversion of mixed plastics waste into useful chemical products.