Mixed plastics waste valorization through tandem chemical oxidation and biological funneling

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.

Construction of microbial consortia for microbial degradation of complex compounds

“…The final microbial consortia could completely degrade 23.2% of a PET film at room temperature. Furthermore, as a result of in-depth research on the degradation pathways of synthetic plastics, it has also become possible to build a microbial community degradation platform to degrade and convert synthetic plastics into high-value products ( Qi et al, 2022 ; Sullivan et al, 2022 ).…”

Characterization and engineering of branched short-chain dicarboxylate metabolism in Pseudomonas reveals resistance to fungal 2-hydroxyparaconate

“…The direct upcycling of plastic monomers to such products was also achieved by engineering non-pathogenic Pseudomonads ( Kenny et al, 2012 ; Werner et al, 2021 ). Recently, a two-stage chemical oxidation and biological funneling approach using engineered P. putida was developed enabling upcycling of various plastics ( Sullivan et al, 2022 ). Application of this method on polypropylene (PP) would result in the release of branched short-chain dicarboxylates (BSCD).…”

Reductive Enzyme Cascades for Valorization of PET Deconstruction Products

“…[10][11][12][13][14][15][16][17] To date, most efforts have harnessed these compounds for either the resynthesis of PET, biological degradation as catabolized carbon sources, or aliphatic building blocks derived from aromatic ring cleavage. [18][19][20] We wondered whether we could design a route to convert PET deconstruction products to upcycled amines as alternatives to these products, while preserving the aromatic nature of the terephthalate monomer (Fig. 1A).…”

“…10–17 To date, most efforts have harnessed these compounds for either the resynthesis of PET, biological degradation as catabolized carbon sources, or aliphatic building blocks derived from aromatic ring cleavage. 18–20…”