An estimated 8 million tons of plastic enter the ocean every year. At this rate, there could be more plastic in the ocean by weight than fish by 2050. The Great Pacific Garbage Patch (GPGP) is the largest accumulation of ocean plastic, covering an area of around 1.6 million square kilometers, roughly three times the size of Texas. Within this patch, there are approximately 1.8 trillion pieces of plastic weighing around 80,000 tons.
However, amid this environmental crisis, scientists have discovered a plastic-eating fungus within the GPGP, offering the slightest glimmer of hope in the battle against marine plastic pollution.
Parengyodontium album, the plastic-eating fungus
Researchers collected fungi samples from floating plastic fragments in the GPGP and isolated a fungus called Parengyodontium album. The fungus is typically found on land, where it decomposes organic waste. However, researchers found that UV-exposed plastic in the ocean creates a microhabitat suitable for the fungus to colonize.
Several types of fungi have shown remarkable potential to feed on plastic waste and break it down into less harmful forms. Because of this, researchers tested P.album and found that it, too, can degrade plastics, including polyethylene (PE), one of the most common plastics found in many single-use plastics like water bottles and plastic bags. Under laboratory conditions, it could break down PE at a rate of about 0.05% a day.
Yet, UV light exposure is crucial for P. album to thrive since UV light from the sun weakens plastics and makes it easier for the fungus to break down (1).
“In the lab, P. album only breaks down PE that has been exposed to UV light, at least for a short period of time. That means that in the ocean, the fungus can only degrade plastic that has been floating near the surface initially,” said lead author Annika Vaksmaa in the paper. “It was already known that UV-light breaks down plastic by itself mechanically, but our results show that it also facilitates the biological plastic breakdown by marine fungi.”
Remediation potential of marine fungi
Parengyodontium album is the fourth known marine fungi that is capable of consuming plastics. The plastic-eating habits of these fungi indicate that they could potentially play a role in mitigating plastic pollution in the ocean.
Unfortunately, as promising as this discovery is, more research will need to be done to make fungi a viable option for large-scale plastic remediation. P. album degrades plastic at a relatively slow rate, which would have an insignificant impact on reducing the overall massive volume of plastic in the ocean before it becomes too polluted. Furthermore, the fungus relies on UV exposure, which means it isn’t effective on plastic in deeper ocean layers or areas where UV light is limited. Nonetheless, scientists are still trying to find ways to scale up the use of fungi as a solution—and quickly, considering the future of the ocean and our planet depend on it.
References
- A. Vaksmaa, H. Vielfaure, L. Polerecky, M.V.M. Kienhuis, M.T.J. van der Meer, T. Pflüger, M Egger, and H Niemann. 2024. “Biodegradation of Polyethylene by the Marine Fungus Parengyodontium Album.” Science of the Total Environment, April, 172819–19. https://doi.org/10.1016/j.scitotenv.2024.172819.
