New enzyme that breaks down plastics in hours could clean up landfills

A new type of enzyme has been created by engineers and scientists at the University of Texas at Austin (USA), capable of decomposing the chemical components of plastics within hours or days.It represents a solution to an important ecological challenge for the environment that would normally take centuries to bring about such degradation under natural conditions.

The new enzyme, named by the research team FAST-PETase, has the potential to solve one of the biggest environmental problems on the planet: what to do with the billions of tons of plastic waste accumulating and polluting the environment in thousands of landfills around the world? Does it threaten soil and groundwater?

The team was able to complete a “circular process” by concentrating their efforts on the well-known polyethylene terephthalate – popular PET – found in soda bottles and cookie wraps. He first broke the plastic into smaller pieces (depolymerization) and then chemically reassembled it (repolymerization). In some cases, the study says, plastic breaks down into monomers in less than 24 hours.

How did scientists create enzymes to quickly break down plastic?

According to research published April 27 in the journal natureThe scientists used hydrolases, enzymes that promote the splitting of organic matter through the use of water. However, they introduced a machine learning algorithm to create mutations in a natural enzyme called PETase, which facilitates the degradation of PET plastics by bacteria.

The experiment included 51 studies of thermoformed and discarded plastic packaging, five different polyester fabrics and fibers, and water bottles, all made from PET. FAST-PETase treated materials were almost completely degraded within a week. Another unprecedented achievement was accelerating the degradation of plastics at low temperatures. Obtained in processes below 50ºC.

The launch of FAST-PETase could represent a relatively inexpensive, portable and scalable differentiator to the required industrial levels.

ARTICLE Nature: DOI: 10.1038/s41586-022-04599-z.