As recently reported by Kew Gardens in their first ever State of the World’s Fungi report, one species of fungi has been discovered that can break down polyester polyurethane. The fungi was discovered in a waste dump in Pakistan by researchers.
The fungus – Aspergillus tubingensis – degrades plastic by feeding on it. In lab experiments, Aspergillus tubingensis mycelia, or the branched, tubular filaments of the fungus, seize the
polyester polyurethane plastic, engendering a breakdown and scarring of the plastic’s surface.
The specific plastic that the fungus ate was polyester polyurethane (PU), which is found in products ranging from fridges to synthetic leather. The time to degrade the plastic was eight weeks.
Researchers hailed the discovery as significant, since PU and other plastics can take decades or even hundreds of years to biodegrade, making them potentially harmful to the surrounding environment.
Dr. Sehroon Khan, of the World Agroforestry Centre and Kunming Institute of Biology, who led the Environmental Pollution study, stated, “Our team’s next goal is to determine the ideal conditions for fungal growth and plastic degradation, looking at factors such as pH levels, temperature and culture mediums.”
The team found that — though this testing is still in early stages — following two months in a liquid medium, Aspergillus tubingensis had degraded a sheet of polyester polyurethane to the point of near-dissipation. It degenerated the polyurethane better under these conditions than on an agar plate and when buried in soil.
According to the study abstract, “Notably, after two months in liquid medium, the PU film was totally degraded into smaller pieces.”
Organisms have fed on plastic waste in prior instances, so this particular finding in the Pakistani landfill site is not the first. This new result goes alongside the accidental discovery of a plastic-eating enzyme by scientists earlier this year when two professors inadvertently altered the enzyme PETease to be better at plastic degrading.