Plastics have only been around for a little over a century, but our world is dominated by it.
And it’s not going away any time soon.
Even if everyone on the planet began switching over to greener alternatives tomorrow, the plastic waste we generate today will take generations to break down.
For instance, a plastic bag from the grocery store can take up to 20 years to decompose.
A plastic straw can take 200 years to decompose.
A plastic water bottle? 450 years.
It can be difficult to take in these metrics without feeling the melancholy of “climate doom” creep in, but scientists, engineers, and innovators around the globe are working overtime to limit waste and build a brighter future.
One key to that future? Plastic-eating bacteria.
In 2016, a research team at Kyoto University discovered and isolated a bacteria that feeds on poly(ethylene terephthalate) — or PET.
As a petroleum-based plastic, PET is found in nearly everything, from water bottles to T-shirts to automotive parts. Because of its chemical make-up, it’s also notoriously hard to break down.
Plastic-eating microbes have long existed, but it was difficult for scientists to cultivate them. But by studying the new bacteria, which scientists dubbed Ideonella sakaiensis, they were able to hone in on the very gene in its DNA that’s responsible for the PET-digesting enzyme.
Armed with this new knowledge, the Kyoto research team was able to manufacture more of the enzyme and replicate its success on a larger scale.
Now, synthetic biologist Chenwang Tang and his fellow researchers at the Chinese Academy of Sciences have figured out how to cultivate the bacterial spores that secrete those enzymes and “bake them” into the very structure of plastic.
In this case, a synthetic polycaprolactone plastic that’s biodegradable.
When this plastic starts to break down, the microscopic spores release enzymes that finish the job and break down the plastic completely — in just 30 days.
“[The plastics] thoroughly disintegrate without the addition of antibiotics, underscoring the robustness of the system,” Tang and his team wrote in their study, which was published in Nature Chemical Biology.
Right now the plastics only exist in the Chinese Academy of Sciences laboratories, but the team hopes that it will be available to the public in just a few years.
One potential use of the “living plastic” could be for packaging materials, like beverage bottles.
“The living plastics remained stable when soaked in soda (Sprite) for 60 days,” Tang added, when they put this theory to the test.
Overall, their goal is to eventually create accessible plastics that are not only reliable but environmentally friendly, breaking down without leaving harmful waste behind.
“Plastics are widely used materials that pose an ecological challenge because their wastes are difficult to degrade,” Tang wrote.
“This study showcases a method for fabricating green plastics that can function when the spores are latent and decay when the spores are activated and sheds light on the development of materials for sustainability.”
Header image via Ivan Radic (CC BY 2.0)
