Photo: Serenity Mitchell
By now you’ve heard that plastic pollution is one of the world’s most pressing environmental concerns. By any measurement, things like single-use plastic bottles are on track to flood landfills and eventually spill into our oceans at scary rates. The Pew Charitable Trust, for example, projects that we’ll be dumping about 29 million metric tons into the ocean per year by 2040, decimating ecosystems and impacting every way we rely on or interact with the ocean.
And it’s a problem that only compounds itself because plastic isn’t biodegradable, meaning once we’ve made it, we’re stuck with it. This has led to scientists researching ways to change that, even employing waxworms to eat the stuff. One heavily researched theoretical solution is to create an enzyme that could essentially dissolve different plastics, and one team of scientists announced this week they have one that can eat plastic bottles six times faster than what was previously possible.
It started in 2016 when scientists discovered a bacteria in Japan that could break the molecular bonds of one of the world’s most-used plastics — polyethylene terephthalate, also known as PET or polyester. “Some bacteria think plastic is fantastic,” they wrote, detailing that the bacteria could break down low-grade plastics in a few days.
That original enzyme was called PETase which they’ve now combined with another called MHETase, typically used to break down cotton. The new “super enzyme” created by the pairing is what they report works six times faster. Just as promising is the fact that researchers project making this a viable technique for breaking down plastics on a large scale “within the next year or two.”
“When we linked the enzymes, rather unexpectedly, we got a dramatic increase in activity,“ said Professor John McGeehan, at the University of Portsmouth, UK. “This is a trajectory towards trying to make faster enzymes that are more industrially relevant. But it’s also one of those stories about learning from nature, and then bringing it into the lab.”
Still, even with the new findings, researchers are intent on upping the ante, as their current innovation isn’t commercially viable.
“There’s huge potential,” said McGeehan. “We’ve got several hundred in the lab that we’re currently sticking together.”
