“Plastic pollution is by far one of the biggest waste issues of our time. The vast majority of it isn’t adequately recycled, which means it often ends up in our oceans, rivers and in landfill. It’s been estimated that 109 million tonnes of plastic pollution have accumulated in the world’s rivers and 30 million tonnes now sit in the world’s oceans – with sources estimating this will soon surpass the total mass of fish,” said Mrs Samat.

The researchers say polypropylene is so infrequently recycled because of its short life as a packaging material and because it often becomes contaminated by other materials and plastics, necessitating new recycling methods that have minimal environmental impact.

Mrs Samat’s PhD supervisor, Professor Ali Abbas from the School of Chemical and Molecular Engineering and Chief Circular Engineer at Circular Australia said: “Despite the massive scale of plastic production and consumption, there has been very little attention paid to plastics degradation under environmental conditions, and our understanding of how plastics can be degraded is limited.”

“One big question our result has raised is – what are the naturally occurring conditions which can fast track the degradation of plastics? We seek to further explore the role of biological processes offered by fungi and other microorganisms.”

Professor Dee Carter, an expert in mycology (the study of fungi) in the School of Life and Environmental Sciences and co-author of the study said: “Fungi are incredibly versatile and are known to be able to break down pretty much all substrates. This superpower is due to their production of powerful enzymes, which are excreted and used to break down substrates into simpler molecules that the fungal cells can then absorb.”

“Often, these fungi have evolved to break down woody materials, but this ability can be repurposed to attack other substrates. This is why we find fungi growing on all sorts of man-made materials like carpets, painted furniture, tile grout, shower curtains, upholstery and even car headlights.

“Recent studies suggest some fungi may even degrade some of the ‘forever chemicals’ like PFAS, but the process is slow and not yet well understood.  There is also evidence that the amount of plastic accumulated in the ocean is less than what might be expected based on production and disposal levels, and there is speculation that some of this ‘missing’ plastic may have been degraded by marine fungi.”