Scientists Discover a New Strain of Marine Fungi Capable of Digesting Plastics

Ocean plastic pollution is a massive global problem, but a recent biological discovery offers a new way to clean up our seas. Researchers recently isolated a marine fungus capable of breaking down polyethylene, the most common type of plastic waste, turning a stubborn environmental hazard into a biological resource.

The Discovery of Parengyodontium album

The fight against ocean pollution took a major step forward in June 2024. Marine biologists from the Royal Netherlands Institute for Sea Research (NIOZ) identified a specific ocean fungus that actually consumes plastic. The fungus, officially named Parengyodontium album, was found living alongside other marine microbes on plastic litter floating in the Great Pacific Garbage Patch.

Led by lead researcher Annika Vaksmaa, the scientific team published their groundbreaking findings in the journal Science of the Total Environment. They revealed that this specific microbial strain can break down polyethylene waste within a matter of weeks. Polyethylene (often labeled as PE) is the ubiquitous material used to make common household items like grocery bags, water bottles, and food packaging.

To understand exactly how effective this fungus is, researchers brought plastic samples from the North Pacific Ocean back to their laboratory in the Netherlands. They cultivated the fungus in simulated seawater environments. Over a period of several weeks, they tracked the exact biological process the fungus used to interact with the plastic waste.

How the Fungus Digests Polyethylene

Breaking down plastic is not an easy task for any organism. Synthetic polymers like polyethylene are specifically designed by humans to last for hundreds of years. However, Parengyodontium album uses the carbon found inside polyethylene as a primary food source.

During the laboratory tests, scientists needed proof that the fungus was actually digesting the plastic, rather than the plastic just breaking apart in the water. To do this, the research team manufactured special plastics enriched with carbon-13 isotopes. When they fed this traceable plastic to the fungus, they could follow the exact path of the carbon.

They discovered that the fungus degrades the polyethylene at a rate of roughly 0.05 percent per day. As it digests the synthetic material, the fungus excretes carbon dioxide as a byproduct. While carbon dioxide is a greenhouse gas, the amount released by this fungal process is incredibly small and matches the natural, everyday respiration of billions of other microbes currently living in the ocean.

Most importantly, the research team noted that the fungus does not just break the plastic into smaller, dangerous microplastics. It actually changes the chemical structure of the waste, biologically removing it from the water entirely.

The Crucial Role of Sunlight

One of the most fascinating details from the NIOZ study is that the fungus cannot do this work alone. It requires direct help from the sun.

Parengyodontium album only breaks down polyethylene that has been previously exposed to ultraviolet (UV) light. When plastic waste floats near the surface of the ocean, intense sunlight beats down on it and slowly degrades the material chemically. This UV exposure weakens the incredibly strong chemical bonds of the plastic.

Once the sunlight has pre-treated the waste, the fungus can step in, attach itself, and finish the job. Because of this strict reliance on sunlight, this specific fungal strain is highly effective at clearing plastic floating near the ocean surface. It is much less effective on plastic waste that has sunk into the dark waters of the ocean floor.

Why Targeting Polyethylene Matters

Finding a natural biological solution for polyethylene is a massive win for marine conservation. The world produces over 400 million tons of plastic every single year. Polyethylene makes up a massive portion of that global total.

Here is why targeting polyethylene is critical for long-term ocean health:

• High Volume: Over 14 million tons of plastic enter the oceans annually. Much of this is single-use polyethylene packaging.
• Toxicity Absorption: As polyethylene sits in the ocean, it acts like a sponge for toxic chemicals in the water. Fish and marine birds often mistake these toxic pieces for food.
• Microplastic Creation: Without biological breakdown, ocean waves simply smash polyethylene into tiny microplastics that contaminate the entire global food chain.

Prior to this discovery, scientists knew of very few marine organisms capable of eating plastic. While researchers previously found a terrestrial soil fungus called Pestalotiopsis microspora in the Amazon rainforest that eats polyurethane, finding a saltwater-adapted organism like Parengyodontium album changes the approach for marine biologists. It joins a very short list of known marine fungi, such as Zalerion maritimum, that show promise in degrading synthetic materials.

Scaling Up Ocean Cleanup Efforts

Currently, organizations like The Ocean Cleanup use massive floating nets and booms to scoop plastic out of the water. These mechanical efforts are highly successful at removing large debris and abandoned fishing nets. However, they cannot catch every piece of plastic, especially as items break down into smaller fragments that slip through the nets.

Biological agents like Parengyodontium album could eventually serve as a secondary, microscopic cleanup crew. While scientists cannot simply dump millions of tons of lab-grown fungi into the open ocean, understanding how this organism works allows researchers to look for similar microbes already living in our waters.

Marine biologists suspect there are many other undiscovered plastic-eating microbes living deep in the oceans. Vaksmaa and her team are currently searching for other marine fungi that might not require UV light to function. Finding a microbe that does not need sunlight could help degrade plastics that have sunk into deep ocean trenches.

Frequently Asked Questions

What specific type of plastic does this marine fungus eat? The fungus Parengyodontium album specifically targets polyethylene (PE). This is the most widely produced plastic in the world, commonly used for plastic bags, packaging materials, and plastic bottles.

Where was this plastic-eating fungus discovered? Researchers from the Royal Netherlands Institute for Sea Research (NIOZ) discovered the fungus living on plastic waste floating in the Great Pacific Garbage Patch, a massive collection of marine debris in the North Pacific Ocean.

Does this discovery mean we can stop recycling? No. While the fungus degrades plastic at a rate of 0.05 percent per day, this biological process is far too slow to keep up with the millions of tons of new plastic entering the ocean each year. Reducing plastic use and improving recycling programs remain the most effective ways to protect the environment.

Can this fungus clean up plastic on the ocean floor? Current research indicates that this specific fungus requires ultraviolet (UV) light from the sun to weaken the plastic before it can digest it. Because sunlight does not reach the deep ocean floor, this fungus is mostly effective on plastic floating near the surface of the water.