Found bacteria that can digest plastic at low temperatures

Microbes capable of digesting plastic at low temperatures have been discovered by scientists in the Alps and the Arctic. This can be a valuable tool in recycling.

Many microorganisms that can do this have already been found, but usually they can only work at temperatures above 30°C. This means that their use in industrial practice is prohibitively expensive due to the required heating. This also means that their use is not carbon neutral.

Scientists from the Swiss Federal Institute WSL have found microbes capable of recycling plastic at 15°C, which could lead to a breakthrough in microbial recycling. The results of scientific work were published in the journal Frontiers in Microbiology.

Dr. Joel Ruti of WSL and colleagues took samples of 19 strains of bacteria and 15 fungi growing on buried plastic stored in the ground for one year in Greenland, Svalbard and the mountains of Switzerland.

The microbes were then grown as single strain cultures in the laboratory in the dark at 15°C. Further testing showed whether they could digest various types of plastic.

Thus, bacterial strains were able to digest plastic and belonged to 13 genera in the types of actinobacteria and proteobacteria, and fungi belonged to 10 genera in the types ascomycota and mucoromycota.

The plastics tested included biodegradable polyethylene (PE) and biodegradable polyester-polyurethane (PUR), as well as two biodegradable blends of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA).

None of the strains could digest PE even after 126 days of incubation on these plastics. But 19 strains (56%), including 11 fungi and 8 bacteria, were able to digest polyurethane at 15°C, and 14 fungi and 3 bacteria were able to digest PBAT and PLA plastic blends.