Swiss researchers identify new group of plastic-eating microbes in colder environments which could revolutionize plastic recycling
In a significant scientific discovery, a team of researchers from the Swiss Federal Institute WSL has unearthed a group of microbes capable of breaking down plastic at lower temperatures. Previous findings had only identified such microbes functioning at higher temperatures, typically around 30 degrees Celsius. This groundbreaking research holds immense potential for revolutionizing plastic recycling efforts and addressing environmental challenges.
Led by Dr. Joel Rüthi and the WSL team, the researchers conducted their investigation in Greenland, Svalbard, and Switzerland, where they encountered microbes with the ability to degrade plastic at 15 degrees Celsius. To delve deeper, they collected samples of 34 types of microbes, including 19 bacteria and 15 fungi, growing on plastic that had been buried for a year in these regions. Subsequently, the team cultivated these microorganisms in a laboratory under dark conditions at 15 degrees Celsius to assess their plastic breakdown capabilities.
The researchers tested various types of plastic, including non-biodegradable polyethylene (PE), biodegradable polyester-polyurethane (PUR), as well as two other biodegradable plastic mixtures, polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA). While none of the microbes could break down polyethylene even after a growth period of 126 days, a significant breakthrough was observed with the degradation of polyester-polyurethane by 19 of the tested microbes. Additionally, 17 microbes successfully broke down the plastic mixtures of PBAT and PLA.
The most effective plastic-eating microbes were found to be two unnamed types of fungi belonging to the neodevriesia and lachnellula families. These fungi exhibited the remarkable ability to break down all tested plastics except polyethylene. This discovery provides an exciting prospect for the development of more energy-efficient processes for plastic degradation.
Current methods of plastic breakdown typically involve high temperatures above 30 degrees Celsius, which are costly to maintain and often rely on fossil fuel usage. However, the newfound microbes that thrive in colder temperatures offer a promising alternative that is more economically viable and environmentally friendly for plastic recycling.
Their findings were published in Frontiers in Microbiology. While this research is a significant step forward, the scientists acknowledge the need for further exploration. They emphasize the importance of conducting additional studies to determine the optimal microbes and temperature conditions for effective plastic degradation. This ongoing research has the potential to unlock new possibilities and reshape the future of plastic recycling.
Examples of mineral medium plus Impranil® (MM + Imp) plates inoculated with microbial strains for evaluation of Impranil® degradation. A: 7 days; B: 14 days; C: 28 days. Photograph: Swiss Federal Institute WSL/Frontiers in Microbiology