Tandem chemical deconstruction and biological upcycling of poly(ethylene terephthalate) to β-ketoadipic acid by Pseudomonas putida KT2440

Allison Z. Werner, Rita Clare, Thomas D. Mand, Isabel Pardo, Kelsey J. Ramirez, Stefan J. Haugen, Felicia Bratti, Gara N. Dexter, Joshua R. Elmore, Jay D. Huenemann, George L. Peabody, Christopher W. Johnson (+4 others)
2021 Metabolic Engineering  
Poly(ethylene terephthalate) (PET) is the most abundantly consumed synthetic polyester and accordingly a major source of plastic waste. The development of chemocatalytic approaches for PET depolymerization to monomers offers new options for open-loop upcycling of PET, which can leverage biological transformations to higher-value products. To that end, here we perform four sequential metabolic engineering efforts in Pseudomonas putida KT2440 to enable the conversion of PET glycolysis products
more » ... : (i) ethylene glycol utilization by constitutive expression of native genes, (ii) terephthalate (TPA) catabolism by expression of tphA2IIA3IIBIIA1II from Comamonas and tpaK from Rhodococcus jostii, (iii) bis(2-hydroxyethyl) terephthalate (BHET) hydrolysis to TPA by expression of PETase and MHETase from Ideonella sakaiensis, and (iv) BHET conversion to a performance-advantaged bioproduct, β-ketoadipic acid (βKA) by deletion of pcaIJ. Using this strain, we demonstrate production of 15.1 g/L βKA from BHET at 76% molar yield in bioreactors and conversion of catalytically depolymerized PET to βKA. Overall, this work highlights the potential of tandem catalytic deconstruction and biological conversion as a means to upcycle waste PET.
doi:10.1016/j.ymben.2021.07.005 pmid:34265401 fatcat:4j2uis4c3bbe3fuvqzt5nd3z4m