Marine fungi decompose polyethylene plastics

In recent years, the problem of marine plastic pollution has become increasingly serious, and there is an urgent need to find effective solutions. Recently, researchers from the Netherlands Institute of Oceanography (NIOZ) have discovered that a fungus living in the ocean can degrade the plastic polyethylene (PE), bringing new hope for solving this global environmental problem. The research results were published in the journal Science of the Total Environment.

Plastic degraders in the ocean

This study reveals that the fungus Parengyodontium album coexists with other marine microorganisms on thin layers of plastic waste and is capable of degrading polyethylene (PE), the most common plastic in the ocean. NIOZ's marine microbiologists, in collaboration with Utrecht University, the Ocean Cleanup Foundation, and research institutions in Paris, Copenhagen, and St. Gallen, Switzerland, have discovered that this fungus can decompose PE into carbon dioxide.

The research team is searching for plastic degrading microorganisms in plastic pollution hotspots in the North Pacific. They isolated marine fungi from collected plastic waste and cultured them in the laboratory using special plastics containing labeled carbon. Research has shown that P. album almost does not utilize carbon from PE when degrading PE, but instead converts most of PE into carbon dioxide and emits it. Although this process produces greenhouse gas carbon dioxide, its amount is equivalent to the amount emitted by human respiration and will not bring new environmental problems.

The key role of ultraviolet radiation

Researchers have also found that ultraviolet radiation in sunlight is crucial for fungi to utilize PE as an energy source. In the laboratory, P. album can only degrade PE exposed to ultraviolet light, which means that in the ocean, this fungus can only degrade plastic floating on the surface of the sea. Ultraviolet radiation can not only mechanically degrade plastics, but also promote the biodegradation process of marine fungi.

Deeper fungal degradation potential

Although P Album is unable to degrade plastic that sinks deep into the ocean, and researchers predict that there may be other undiscovered fungi in the ocean that can also degrade plastic. NIOZ researchers suggest that marine fungi are capable of decomposing complex carbon materials, so there may be more types of fungi involved in plastic degradation.

The urgency of plastic pollution

Every year, humans produce over 400 billion kilograms of plastic, and it is expected that this number will at least triple by 2060. A large amount of plastic waste eventually flows into the ocean, from the polar regions to the tropics, floating in surface water and sinking into the seabed, forming what is known as "plastic soup". NIOZ's chief researcher Vaksmaa pointed out that a large amount of plastic accumulates in subtropical circulation, which is almost stationary, making it difficult for plastic to escape once it enters. In the North Pacific Subtropical Circulation alone, approximately 80 million kilograms of plastic have drifted, making it one of the six major global circulations.

With the intensification of global plastic pollution, it is particularly important to search for and study more plastic degrading microorganisms. The discovery of Parengyodontium album provides us with new solutions, but we still need to continue exploring and find more organisms that can degrade plastics in different environments to jointly address this global challenge. Through continuous efforts, we are expected to gradually reduce the threat of plastic pollution to marine ecosystems and protect the future of the earth.