On April 8, 2020, researchers from the University of Toulouse in France published an article in the peer-reviewed journal Nature announcing the discovery of a new enzyme that can efficiently break down plastics made from polyethylene terephthalate (PET). The novel enzyme is able to depolymerize a minimum of 90% of PET into monomers over the course of ten hours “with a productivity of 16.7 grams of terephthalate per liter per hour (200 grams per kilogram of PET suspension, with an enzyme concentration of 3 milligrams per gram of PET).”
The authors report that they are also able to “show that biologically recycled PET exhibiting the same properties as petrochemical PET can be produced from enzymatically depolymerized PET waste,” which they say will help contribute “towards the concept of a circular PET economy.” Earlier research into enzymes to support the breakdown of PET has shown limited efficiency, and this enzyme is reported to outperform all other hydrolase enzymes developed so far.
Polyethylene terephthalate (PET) is the most abundant polyester plastic in the world, and near 70 million metric tons of it are reported to be produced annually specifically for use in textiles and packaging. The authors comment that it is also very difficult to hydrolyze due to the high ratio of aromatic terephthalate units.
Jessi Devenyns (April 13, 2020). “Scientists discover enzyme that breaks down PET plastic in a few hours.” Food Dive
Jim Cornall (April 14, 2020). “Carbios develops enzyme for PET depolymerization.” Dairy Reporter
Karen Laird (April 14, 2020). “Enzymatic recycling earns scientific recognition.” Sustainable Plastics
Tournier, V. et al. (April 8, 2020). “An engineered PET depolymerase to break down and recycle plastic bottles.” Nature (580).