Newly discovered bacteria and fungi can digest plastics at low temperatures. However, they don’t stand a chance against a type of plastic.
Small creatures, big sensation. In the Swiss Alps, researchers have now identified fungi and bacteria that can digest certain plastics.
The microbes were found in the Grisons Alps in the canton of Graubünden and in the Arctic, the researchers report in the journal “Frontiers in Microbiology”. They can digest the plastics PUR (polyurethane) and PBAT/PLA, but they don’t stand a chance against polyethylene, the most commonly used plastic worldwide.
Active in cool temperatures
What is fascinating is that the species discovered can decompose plastic at temperatures as low as around 15 degrees Celsius. Several microorganisms that are able to digest plastic were already known beforehand. “But these were typically tested at over 30 degrees Celsius,” said lead author Joel Rüthi from the WSL research institute of the Keystone-SDA news agency.
Polyurethane (PUR) is found, for example, in household sponges, mattresses and sneakers. Among other things, compostable plastic bags are made from PBAT/PLA. Polyethylene (PE) is the perfect plastic for canisters, injection molded parts or pipes.
The fact that the microorganisms are so frugal when it comes to temperature can be helpful when used in industrial recycling. This reduces the energy required and, according to Rüthi, makes the breakdown of plastic with enzymes cheaper and more climate-friendly.
Plastic buried on mountain tops
It is interesting how the researchers found the bacteria: Rüthi and his research colleagues buried various types of plastic on the summit of the 2,979 meter high Muot da Barba Peider mountain in Val Lavirun in eastern Switzerland and in the Arctic. After only three days, the first tiny traces of bacterial damage could be seen on the plastic parts. After a few more weeks, the scientists then took samples and found 19 strains of bacteria and 15 strains of fungi that could decompose the plastic.
