A new study outlines the use of a specially created enzyme variant that vastly reduces the time it takes to break down the components of plastics. We could even use the enzyme variant to clean up sites contaminated by plastic pollution, say the team that developed it.
In tests, products made from the polymer polyethylene terephthalate (PET) were broken down in a week and, in some cases, 24 hours – these are products that can take centuries to degrade properly in natural conditions.
“The possibilities are endless across industries to leverage this leading-edge recycling process,” says chemical engineer Hal Alper from the University of Texas at Austin.
“Beyond the obvious waste management industry, this also provides corporations from every sector the opportunity to take a lead in recycling their products.”
The team has called the enzyme FAST-PETase (functional, active, stable, and tolerant PETase). They developed the enzyme from a natural PETase that allows bacteria to degrade PET plastic and modified it using machine learning to pinpoint five mutations that would enable it to degrade the plastic faster under different environmental conditions.
Once the enzyme variant did its job of cutting the plastic down into its basic molecular units (depolymerization), the researchers then demonstrated they could put the plastic back together again (repolymerization) using chemical processes to create new plastic products.
Finding FAST-PETase involved the study of 51 different post-consumer plastic containers, five different polyester fibers, and fabrics and water bottles made from PET.
In tests on all of these products, the enzyme variant proved its effectiveness and at temperatures less than 50 degrees Celsius (122 degrees Fahrenheit).
The research has been published in Nature.