Scientists create FAST-PETase enzyme that breaks down plastic waste in hours, not decades

Scientists create FAST-PETase enzyme that breaks down plastic waste in hours, not decades. New research suggests the use of a specially created enzyme that greatly reduces the time it takes to break down plastic into smaller parts. We could even use a different enzyme alternative to clean sites that are contaminated with plastic waste, says the team that built it.

In experiments, products made of polymer polyethylene terephthalate (PET) were broken within a week and, in some cases, 24 hours - these were products that could take centuries to decompose in natural conditions. "Opportunities are endless across industries to implement this advanced recycling process," said chemical engineer Hal Alper of the University of Texas at Austin.

Apart from the transparent waste management industry, this also gives companies from all sectors the opportunity to lead in the recycling of their products." The group is called the enzyme FAST-PETase (an active, efficient, stable, and tolerant PETase). They form an enzyme from natural PETase that allows bacteria to degrade PET plastic and transform it by using machine learning to identify five mutations that will cause them to degrade plastic quickly under different environmental conditions.

Once the enzyme variant has done its job of cutting plastic down to its basic molecular units (depolymerization), researchers have shown that they can recycle plastic (repolymerization) using chemical processes to make new plastic products. Finding  FAST-PETase involved research into 51 consumer plastic containers, five different polyester fibers, water bottles, and fabrics made from PET.

In the experiments of all these products, the enzyme variant has proven its effectiveness also at temperatures below 50 degrees Celsius. "When you are considering clean-up applications, you need an enzyme that can work in the environment at ambient temperature," Alper said. "This requirement is where our technology has the greatest potential in the future."

PET is in many consumer packaging, from textiles to soda bottles. By itself, it is estimated that it makes up about 12 percent of the world's total waste. If that figure isn't scary enough, try this: Globally, less than 10 percent of all plastics have been recycled.

The introduction of FAST-PETase can help in some way. Researchers say that it is cheaper, more affordable, and less difficult to scale up to the kind of industry standards it would require. Currently, the most common way to dispose of plastic is to throw it in a garbage dump where it rots very slowly, or burns it - more expensive, uses more energy and fills the atmosphere with harmful gases. 

It is clear that some strategies are needed, and this could be one of them. "This work really demonstrates the potential for integration in a variety of fields, from biotechnology to chemical engineering to synthetic ingenuity," said biologist Andrew Ellington of the University of Texas at Austin.