Plastics' metabolic potential as biotechnological carbon sources: A review and future goals

The plastic dilemma necessitates immediate action, particularly when it comes to the end-of-life of plastics. Microbial metabolism may create new avenues for recycling mixed plastic fragments, which are currently challenging to recycle. These carbon sources may be employed in biotechnology to upcycle plastic waste into useful goods like bioplastics and bio surfactants, thanks to breakthrough methods for degrading polymers to oligo- and monomers. We summarized well-known monomer breakdown routes and calculated potential yields for compounds of industrial importance. We generated replacement scenarios for current fossil-based synthesis methods for the same products using this knowledge. As a result, we draw attention to fossil-fuelbased goods for which plastic monomers might be a viable carbon source. The (in-)efficiency of the petrochemical routes (i.e., carbon, energy usage) defines the possibility of biochemical plastic upcycling, not the maximum yield of product on substrate of the biochemical route. Our findings might be used to guide future metabolic engineering efforts aimed at creating a more sustainable plastic economy.