A New Enzyme Found in Compost Just Set a Speed Record for Breaking Down Plastic

SEATTLE (Waste Advantage): A plastic container thrown into landfill can take hundreds of years to break down naturally, but a newly discovered enzyme could eat up the waste in less than a day. The highly efficient polyester hydrolase, known as PHL7, was recently found in a German cemetery munching through compost. In the lab, researchers found it was able to decompose polyethylene terephthalate (PET) by 90 percent within 16 hours. PHL7 isn’t the first natural ‘plastic eater’ discovered by scientists, but it is the fastest.

In 2016, a PET-guzzling enzyme, called LLC, was found at a recycling plant in Japan. In the years since, it’s been heralded as a gold-standard plastic chomper. But the newly found PHL7 is two times faster at the job. Since 2016, the LLC enzyme has been tweaked by scientists to create an even more voracious mutant than is natural, yet even this synthetic creation has a thing or two to learn from PHL7.  “The enzyme discovered in Leipzig can make an important contribution to establishing alternative energy-saving plastic recycling processes,” says microbiologist Wolfgang Zimmermann from Leipzig University in Germany.

“The biocatalyst now developed in Leipzig has been shown to be highly effective in the rapid decomposition of used PET food packaging and is suitable for use in an environmentally friendly recycling process in which new plastic can be produced from the decomposition products.” Unfortunately, neither PHL7 nor LCC can fully degrade PET plastics with higher crystallinity (more organized molecular structure), such as the ones used in some bottles.

Courtesy: www.wasteadvantage.com