Swiss scientists think they’ve discovered a new way to tackle plastic pollution. In a recently published study, they explain that at low temperatures, microbes would be able to “digest” certain plastics. Explanations.
A new step forward in the fight against plastic pollution? In Switzerland, researchers at the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) have identified microbes that are able to break down plastic at low temperatures (15°C). The scientists explain in their study, published May 10, 2023 in the journal Frontiers in Microbiology, that this discovery could help to counteract the increasing plastic pollution.
This “Plastic Eating Microbes”, as Uzbek & Rica magazine calls them, have been found in alpine and arctic soils. To identify them, microbiologist Joel Rüthi, the lead author of this research, and his team extracted plastics from the soil of the Alps and Greenland, explains a May 11 WSL press release. They also isolated microbes from other plastics also buried in Greenland for a year and from waste collected on Norway’s far north island of Spitsbergen.
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“Normal” plastic is resistant to microbes
In the lab, researcher “Then he examined the bacteria and fungi that grew there over the course of a few months.”, WSL continues. The result was that after 126 days of incubation in the dark at 15°C, more than half of the tested strains (56%) could degrade three types of plastics: biodegradable polyester polyurethane, polybutylene adipate terephthalate and polylactic acid ester. As for the so-called “normal” plastic, the polyethylene that can be used to make food wrap, flexible containers, or even certain toys, no strain has been able to “digest” it.
“The next big challenge will be to identify the enzymes [substances organiques] of microbial plastic degradation and to optimize the process to obtain large amounts of enzymes.”, explains Beat Frey, co-author of the study, quoted by the British newspaper The Guardian. Normally, microbes use the enzymes produced by microbes to break down plant cells.
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Reduce recycling costs
The researchers are satisfied with these results for the time being. Especially since the enzymes of the previously known microbes need temperatures above 30°C to break down plastic on an industrial scale. “This type of recycling is therefore very energy- and resource-intensive”, shows the WSL. With their discovery, the Swiss researchers could help reduce the costs and environmental impact of the enzymatic plastics recycling process.
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Other enzymes are of interest to researchers. In October 2022, the magazine Ça m’intérieur explains: “Researchers have found that enzymes in the saliva of moth larvae can break down polyethylene, one of the most commonly used plastics in the world.”.