Microplastics Removal with Fungi

What are microplastics?

After climate change, one of the biggest threats to Earth is increasing plastic pollution. Microplastics are plastic particles smaller than 5 mm, risking water, food supplies, air, soil, ice, and whatnot. Other than direct harmful health impacts, they may also contain harmful chemicals, additives, and bacteria, which could endanger the health of people and animals.

With their ability to infiltrate even the deepest part of the ocean and the highest mountain peaks, microplastics have become a persistent and annoying environmental problem. Effective solutions to this widespread issue are still a mystery. Despite this difficulty, an unexpected helper—fungi—has taken all attention. In this blog, we discuss how fungi plays its role in the removal of microplastics.

What are fungi?

Fungi are robust and diverse organisms. Fungi can range from molds found in water to mushrooms in soil and have an incredible ability to colonize and convert microplastics into biodegradable waste. Since fungi could be used for bioremediation in polluted areas, this finding shows great promise for combating the extensive problem of plastic pollution. This mutually beneficial relationship inspires optimism for the future of sustainable solutions that can lessen the impact of plastic pollution while simultaneously decreasing the need for traditional, energy-intensive treatment processes.

How do fungi degrade microplastics?

Certain fungi may create enzymes called esterases, protease, lipase, laccase, peroxygenases, manganese peroxidase, and cutinases that can degrade the complex polymers found in microplastics. According to recent research, fungi can break polyethylene terephthalate (PET) a  popular kind of plastic widely used to make bottles and other packaging materials.

Enzymes secreted by certain types of fungi can degrade organic materials, reducing their molecular complexity. In addition to natural polymers, fungi can break down synthetic ones. The plastic polymers can be oxidized or hydrolyzed by enzymes produced by fungi, which can then add functional groups that make the surface more hydrophilic. Because of this, the fungus can break down the plastic into tiny pieces, which they can then mineralize or metabolize into water, biomass, and carbon dioxide.

Which fungi do the job?

1. Penicillium species are also filamentous fungi that produce enzymes such as lipase, esterase, and laccase that break down the microplastics. They can also release pro-oxidant ions, like manganese, which can accelerate the breakdown of plastic polymers.
2. Pleurotus species are edible mushrooms that can grow on straw, wood, and corn cobs, among other things. They can degrade microplastics by making enzymes like lipase, laccase, and manganese peroxidase, which can oxidize or hydrolyze the plastic polymers
3. Aspergillus species are filamentous fungi that can make enzymes called cutinase, lipase, and protease that can cut the ester bonds in the plastic polymers and grow on food, dirt, and plant debris, among other things.
4. Phanerochaete chrysosporium is a white-rot fungus that can degrade lignin, which is an organic compound found in wood. Also, it can break down microplastics by creating ligninolytic enzymes like manganese peroxidase and unspecific peroxygenases. These enzymes can make hydroxyl radicals that can attack the plastic polymers.

Limitations

Undoubtedly fungi are helpful in the breakdown of microplastics but certain conditions need to be optimized. These conditions include microplastic quantity, type, size, and morph, fungal species, and enzyme activity. All factors combined play a role in the lengthy and complicated biodegradation process in which fungus commences. Extensive studies and experimentation are required to enhance and facilitate the fungal decomposition of microplastics. Also, an assessment of the ecological and health ramifications of the fungal decomposition of microplastics needs to be done.

How to consume less microplastic through food

Conclusion

Microplastics are a major threat to our environment after climate change, but luckily there is a natural and long-term solution that can solve this problem. fungi can play a role in breaking them down and treating microplastics effectively and affordably. Some fungal species like Penicillium, Pleurotus, Aspergillus,  and Phanerochaete chrysosporium species have the right enzymes to degrade polyethylene and polyurethane, among other plastic polymers, according to the research. Fungal metabolism allows them to use plastics as a carbon source, reducing them to smaller chemicals that other organisms can absorb or break down further.

Scientific papers about fungal degradation of microplastics in 2023

1. Nasrabadi, A. E., Ramavandi, B., & Bonyadi, Z. (2023). Recent progress in biodegradation of microplastics by Aspergillus sp. in aquatic environments. Colloid and Interface Science Communications, 57, 100754.
2. Cai, Z., Li, M., Zhu, Z., Wang, X., Huang, Y., Li, T., … & Yan, M. (2023). Biological degradation of plastics and microplastics: A recent perspective on associated mechanisms and influencing factors. Microorganisms, 11(7), 1661..
3. Rohrbach, S., Gkoutselis, G., Mauel, A., Telli, N., Senker, J., Ho, A., … & Horn, M. A. (2023). Setting new standards: Multiphasic analysis of microplastic mineralization by fungi. Chemosphere, 141025.
4. Thakur, B., Singh, J., Singh, J., Angmo, D., & Vig, A. P. (2023). Biodegradation of different types of microplastics: Molecular mechanism and degradation efficiency. Science of The Total Environment, 877, 162912.
5. Varshney, S., Gupta, V., Yadav, A. N., Rahi, R. K., & Neelam, D. K. (2023). An overview on role of fungi in systematic plastic degradation. Journal of Applied Biology and Biotechnology, 11(3), 61-69.
6. Vaksmaa, A., Guerrero-Cruz, S., Ghosh, P., Zeghal, E., Hernando-Morales, V., & Niemann, H. (2023). Role of fungi in bioremediation of emerging pollutants. Frontiers in Marine Science, 10, 1070905.