Very little of our plastic waste is actually recycled; it’s either combusted for energy or ends up in landfill or the ocean. But a new a study of a strain of bacteria that digests poly(ethylene terephthalate) (PET) has turned into the accidental creation of an enzyme that works to break down plastic a little faster.
However, there are limitations to the enzyme and a potentially disastrous side-effect. Firstly, it’s not an immediate solution to plastic pollution, according to Emily Flashman, research fellow in Enzymology at the University of Oxford.
“The improvements to the PETase activity were not dramatic, and we are nowhere near a solution to our plastic crisis,” she wrote.
For now, this discovery could aid further research to engineer optimised forms of plastic-eating enzymes with the goal of inventing a bio-recycling procedure. Also, you can’t just let the bacteria loose to munch on things. If nature continues in its course, it’s possible that the bacteria could evolve even more and eventually start attacking other forms of plastic, damaging structures and products designed to last – the keyboard we’re typing on, for example.
In a nutshell, “The plastics industry would face the serious challenge of preventing its products becoming contaminated with hungry micro-organisms,” Flashman wrote.
The enzyme ‘accident’ was thanks to researchers from University of Portsmouth and the US Department of Energy’s National Renewable Energy Laboratory (NREL). They had been analysing the structure of PETase, an enzyme secreted by a strain of bacteria called Ideonella sakaiensis, which were discovered by Kyoto University scientists in 2016. PETase splits the chemical bonds that make PET so durable and leaves behind soluble chemical units that could be used to make new plastic, thereby creating a closed-loop recycling system.