Recently, a new research article on the microbial open-loop upcycling of mixed plastics has recently been published in \u201cTrends in Biotechnology\u201d. The study was led by Prof. Lars Blank\u2019s group at the Institute of Applied Microbiology (iAMB), RWTH Aachen University, in collaboration with partners from the Institute of Biochemistry at the University of Greifswald.<\/p>\n\n\n\n
In this work, we developed a genome-engineered Pseudomonas putida<\/em> ETAB strain capable of simultaneously utilizing five plastic-derived monomers: ethylene glycol (EG), terephthalic acid (TA), adipic acid (AA), 1,4-butanediol (BDO), and L-lactic acid (LA). These monomers can be obtained from the hydrolysis of common plastics, including polyethylene terephthalate (PET), polyester polyurethanes (PUs), poly(butylene adipate-co-terephthalate) (PBAT), and polylactic acid (PLA).<\/p>\n\n\n\n The robustness of the engineered strain was demonstrated in a 21-day continuous fermentation with alternating mixed-monomer feeds, during which stable growth and efficient substrate utilization were maintained. Beneficial adaptive mutations identified during the fermentation were subsequently used to further improve the strain through reverse engineering. Additional genomic modifications enabled the production of the versatile platform chemical (R<\/em>)-3-hydroxybutyrate (R-3HB), reaching a concentration of 0.70 g\/L directly from enzymatic hydrolysates of mixed plastics.<\/p>\n\n\n\n Together, these results establish Pseudomonas putida<\/em> as a versatile microbial platform for the valorization of complex plastic-derived feedstocks and demonstrate the potential of open-loop recycling to convert mixed plastic waste into value-added bioproducts.<\/p>\n\n\n\n This study was supported by the Werner Siemens Foundation in the frame of the WSS Research Centre \u201ecatalaix\u201c.<\/p>\n\n\n\n The publication is available here:<\/p>\n\n\n\n