Microbial fermentation of polyethylene terephthalate (PET) plastic waste for the production of chemicals and electricity

Ideonella sakaiensis (I. sakaiensis) can grow on polyethylene terephthalate (PET) as the sole carbon and energy source. Previous work has shown that conversion of the hydrolysis products terephthalic acid (TPA) and ethylene glycol (EG) under aerobic conditions released carbon dioxide and water while yielding adenosine triphosphate (ATP) through oxidative phosphorylation. This study demonstrates that under anaerobic conditions I. sakaiensis ferments PET to the feedstock chemicals acetate and ethanol while co-producing ATP by substrate-level phosphorylation. In addition to PET, maltose, EG, and ethanol can also serve as fermenting substrates. Co-culturing of I. sakaiensis with electrogenic Geobacter sulfurreducens produced electricity from PET or EG. This newly identified plastic fermentation process by I. sakaiensis provides a novel biosynthetic route to produce high-value chemicals and electricity from plastic waste streams.