Fungi Species Capable of Biodegrading Microplastics in Soil Identified

Professor Dr. Sevcan Aydın, a faculty member at Istanbul University’s Faculty of Science, Department of Biology, announced that they have identified seven different fungal species capable of biologically degrading microplastics present in the soil and utilizing them as a nutrient source.

Microplastics, defined as plastic particles smaller than five millimeters, can be transported to agricultural lands through water, posing a long-term risk to soil structure.

Conducting the TÜBİTAK 1001 project titled “Development of Bioremediation Methods Designed with Biotechnological Applications for the Removal of Microplastic Pollution in Soils,” Dr. Aydın emphasized that microplastics reduce soil biodiversity and lead to the extinction of soil-dwelling organisms.

Highlighting that microplastics can enter the human body through the food chain, Aydın stated:
“[Microplastics] contribute to the increase of harmful pathogens and disease-causing organisms. Plants grown in contaminated soil absorb microplastics through their roots. When these plants are consumed by animals and humans, microplastics are transferred into the human body. Controlling microplastic accumulation in agricultural soils is crucial to reducing the microplastic burden on human health.”

Aydın pointed out that wastewater treatment plants are not designed to remove this contaminant, leading to high concentrations of microplastics in both treated wastewater and sludge. Due to the use of these materials in agricultural irrigation and fertilizer, large amounts of microplastics are introduced into the soil.

Microplastic Levels in Agricultural Lands are 4 to 24 Times Higher Than in Oceans

Aydın stressed that microplastics in soils have a far greater environmental impact than those in aquatic ecosystems. Referring to United Nations (UN) data, she noted that microplastic contamination in agricultural lands is 4 to 24 times higher than in oceans, and the majority of microplastics found in the human body originate from soil.

Explaining that they are working on biological methods to mitigate soil microplastic pollution, Aydın stated: “Our goal is to remove microplastics from soil through fungi and algae. Fungi, in particular, use their enzymes to degrade microplastics and subsequently consume them as a nutrient source. To identify these organisms, we collect soil samples from microplastic-contaminated environments. We isolate microorganisms from these samples without adding any external carbon or nutrient sources, ensuring that only organisms capable of utilizing microplastics survive. This process demonstrates that these organisms naturally use microplastics in their biological cycles, making the approach entirely biological.”

Underlining their focus on utilizing local microorganisms to benefit Turkey’s soils, Aydın stated that they initially selected a study site in Diyarbakır.

Aydın elaborated on the research methodology, explaining:
“We selected an agricultural field with high microplastic contamination due to irrigation with treated wastewater. Using different isolation methods, we identified ten fungal species and tested them for their ability to degrade microplastics. Given that microplastics exist in various forms, we specifically examined their ability to degrade polyethylene, one of the most difficult types to break down. At this stage, seven fungal species were found to be successful."

She noted that these fungi achieved over 35% degradation of microplastics. A literature review confirmed that these seven fungal species had not been previously reported for plastic degradation. Furthermore, some of these fungi were identified as the first to biodegrade polyethylene, making them unique and highly valuable for environmental applications.

Aydın also revealed that some of the fungi belong to species previously undescribed in scientific literature and will be named by their research team. She emphasized that by collecting samples from microplastic-contaminated soils, their chances of discovering previously unknown fungal species were significantly increased.

Explaining that the study consists of three stages, Aydın stated:
“In the first stage, we isolated fungi and tested their efficiency in laboratory microcosm experiments using different plastic types. The successful fungal species will then be tested under controlled conditions in greenhouse experiments during the second stage. Finally, in the third stage, these fungi will be applied to the selected agricultural site in Diyarbakır to evaluate their ultimate effectiveness in real-world conditions.”

Both Greenhouse and Field Trials Will Be Conducted

Highlighting that the primary goal is to enable the widespread application of these fungi in agricultural lands, Aydın emphasized: “One of the most critical aspects of our project is that we will conduct both greenhouse and field trials. Laboratory conditions can be controlled to optimize degradation efficiency, but our goal is to ensure that these fungi remain effective in natural environments and are sustainable.”

Aydın pointed out that the selected fungi not only degrade microplastics but also enhance soil biodiversity. Their team plans to develop solutions that will allow farmers and agricultural experts to use these fungi easily.

Emphasizing the novelty of their research, Aydın stated:
“Similar studies worldwide have primarily focused on bacteria, while our research is the first to investigate the microplastic degradation capabilities of eukaryotic organisms such as fungi and algae. While previous studies have only tested efficacy under laboratory conditions, our field application will demonstrate the real-world effectiveness of fungal-based microplastic biodegradation.”

Source: Anadolu Agency