Microbial Fermentation of Polyethylene Terephthalate (PET) Plastic Waste for the Production of Chemicals or Electricity**

Abstract

Ideonella sakaiensis (I. sakaiensis) can grow on polyethylene terephthalate (PET) as the major carbon and energy source. Previous work has shown that PET conversion in the presence of oxygen released carbon dioxide and water while yielding adenosine triphosphate (ATP) through oxidative phosphorylation. This study demonstrates that I. sakaiensis is a facultative anaerobe that ferments PET to the feedstock chemicals acetate and ethanol in the absence of oxygen. In addition to PET, the pure monomer ethylene glycol (EG), the intermediate product ethanol, and the carbohydrate fermentation test substance maltose can also serve as fermenting substrates. Co-culturing of I. sakaiensis with the electrogenic and acetate-consuming Geobacter sulfurreducens produced electricity from PET or EG. This newly identified plastic fermentation process by I. sakaiensis provides thus a novel biosynthetic route to produce high-value chemicals or electricity from plastic waste streams.

Biotransformation of ethylene glycol to glycolic acid by Yarrowia lipolytica: A route for poly(ethylene terephthalate) (PET) upcycling

“…Recently, many reports have been emerging in literature exploring different strategies to upcycle PET monomers into higher‐value molecules in order to provide cost‐effective biological methods proposed to deal with plastic wastes. [ 24–27 ] For instance, Tiso et al. [ 28 ] produced two different bioplastics—poly(hydroxyalkanoate) and bio‐based poly(amide urethane)—using an engineered P. putida that consumes EG and TPA released from PET enzymatic hydrolysis.…”