With 350 million metric tons of plastic waste flooding the planet every year, fungus and other microorganisms could be a surprising solution.

Throughout 2023, researchers conducted several studies aimed at identifying fungi that can break down plastic waste. Researchers in Australia and China found over a hundred types of fungus that can break down common types of plastics. These discoveries come among hundreds of others as researchers continue searching for microorganisms that can help reduce plastic waste.

The term plastic refers to polymer materials, which are long chains of molecules that can be naturally occuring or man-made. Synthetic polymers, like the materials usually used for water bottles or containers, are what people usually think of when they hear the term plastic. Made from carbon atoms drawn from fossil fuels, the entire life cycle of synthetic plastics is detrimental to the environment.

Despite efforts to recycle plastics and limit consumption, only about 5% of recycled plastics are reused, with the rest ending up in the landfills or environment. This issue has led researchers to search for alternative solutions, and as of July 2023, 436 microorganisms that can degrade plastics have been identified. Of these microorganisms, at least 184 species are fungi. Because of the enzymes they produce, some fungi can break down and absorb materials like plastics.

Researchers from around the world have discovered hundreds of these fungi munching away on plastics in natural environments. In Jiangsu, China, researchers have found many plastic-degrading fungi and bacteria in the coastal salt marshes. The researchers also found that microorganisms do not only have the ability to break down plastics, but they have begun creating “plastispheres”. In these “plastispheres”, a unique microbiome is created surrounding plastic waste, exhibiting microorganisms' adaptability in polluted environments. 

While the study of the plastic-degrading microbiome in Jiangsu’s coastal salt marshes focused on the synthetic polymer Polycaprolactone (PCL), another study identified that two types of fungus can break down Polypropylene (PP). Polypropylene is another synthetic polymer that is only successfully recycled 1% of the time, despite making up about 28% of plastic waste. The researchers found that both Aspergillus terreus and Engyodontium album fungi are capable of breaking down PP when the PP has been pre-treated by heat or UV light. These fungi can often be found in plants or soil, making them a promising and plentiful resource for reducing plastic waste. 

Researchers in this field hope that these findings will be stepping stones toward understanding the conditions that allow microorganisms to break down plastics naturally. As further evidence surfaces showcasing the power of fungi and other microorganisms to break down other harmful pollutants, such as ‘forever chemicals’ like PFAS, the journey to find natural solutions to pollution is well underway.