Mycoremediation
The Use of Fungi To Break Down Environmental Pollutants
Author: Abby Molloy
Photo by: Pheonix Han on Unsplash
The poor management of waste from households, agricultural processes, and industries is an ever-growing concern. Worsening water and soil pollution have devastating consequences for the environment and disproportionately impact vulnerable populations, exacerbating health and resource disparities. Low-income communities face high pollutant exposures and often lack the resources to remove toxins from their environment. Therefore, it is essential to protect and decontaminate these crucial resources.
Soil Pollution
Impacts and consequences
Healthy soils are essential to maintaining food security and clean water, preserving biodiversity, adapting to climate change, and promoting a sustainable future (Food and Agriculture Organization of the United Nations, 2018).
Pollution impacts the organic matter and filtration capacity of soils, contaminates groundwater, and leads to an imbalance of nutrients (Food and Agriculture Organization of the United Nations, 2018).
Soil contaminants enter the food chain through plant matter and cause a variety of diseases (Gangadhar, 2014).
In addition to human health and environmental impacts, soil pollution also has economic costs due to a reduction in crop production (Martinho, 2020).
Main contributors
Unsustainable agricultural practices contribute to a significant portion of soil contamination by reducing organic matter and releasing chemicals into soils and groundwater (Food and Agriculture Organization of the United Nations, 2018) (Martinho, 2020).
Some of the most common soil pollutants include heavy metals (Zwolak et al., 2019) and persistent organic pollutants (Sakshi et al., 2019).
Water Pollution
Impacts and consequences
Water pollution has become one of the most serious ecological threats facing our world (Chaudhry et al., 2017).
Waste and toxic chemicals harm aquatic ecosystems and reduce aquatic biodiversity (Azvedo-Santos et al., 2021).
Contaminated drinking water is linked to transmission of diseases such as cholera, diarrhea, dysentery, hepatitis A, typhoid, and polio (World Health Organization, 2019).
At least 2 billion people use drinking water from a contaminated source (World Health Organization, 2019).
By 2025, half of the world’s population is estimated to live in water stressed areas (World Health Organization, 2019).
Main contributors
The greatest threats to water quality are pollutants and waste from industries like mining, urban development, and agriculture (Chaudhry et al., 2017).
Major water pollutants include non-biodegradable plastics, heavy metals, synthetic chemicals, sewage, pesticides, and fertilizers (Chaudhry et al., 2017).
See also the Marine PAH, Marine Plastics, and Wastewater Disparities pages.
What is Mycoremediation?
Mycoremediation - the use of fungi to break down toxic waste - is an environmentally-friendly, effective, and economical method of addressing water and soil pollution. Fungi are powerful natural decomposers which convert dying organic matter into compost to nourish new life (Monroe, 2019). They can break down anything hydrocarbon-based, show fast and robust growth, are resistant to heavy metals, and can adapt to fluctuating pH and temperatures. This makes them an ideal candidate to help degrade and absorb harmful water and soil pollutants (Akhtar et al., 2020).
6 Ways Mushrooms Can Save the World - TED talk by Paul Stamos
Recommended section: 8:03 to 10:32
Common Fungi used in Mycoremediation
Photo by: Edgar Castrejon on Unsplash
Pleurotus ostreatus
Common name: Oyster mushrooms
Remediate: PCB's, PAH's, cadmium, mercury, dioxins
Photo by: Suzanne Shroeter on Flickr
Coprinus comatus
Common name: Shaggy mane
Remediates: Arsenic, cadmium, mercury
Photo from: Wikipedia Commons
Stropharia rugosoannulata
Common name: King strophoria
Remediates: E-coli and other biological contaminants
Photo by Andrew Cannizzaro on Flickr
Trametes versicolor
Common name: Turkey tail
Remediates: PAH's, TNT, organophosphates, mercury
Source: Mycoremediation, 2018
Promising Discoveries
Heavy Metals
Heavy metals (HMs) are released into the environment through industrial processes like mining and fossil fuels combustion (Akhtar et al., 2020). They can have carcinogenic effects in humans, impair physiological activities of plants, and cause lethal damage to aquatic life (Akhtar et al., 2020).
Photo from: Kumar et al., 2021
Fungi can tolerate and resist toxicity of HMs, as well as adsorb large quantities of HMs (Kumar et al., 2021).
Researchers have shown multiple fungal species can remove metals from an environment in both their living and dead forms (Kumar et al., 2021). Species include Aspergillus, Trichoderma, Fusarium, and Penicllium.
Studies have also shown the potential of oyster mushrooms (Pleurotus) to remediate heavy metals due to their large biomass and high biosorption capacity (Kapahi et al., 2017).
Polycyclic Aromatic Hydrocarbons
Polycyclic Aromatic Hydrocarbons (PAHs) are one of the main pollutants released by incomplete combustion of coal, wood, and petroleum products. Exposure can detrimentally impact ecosystems and cause diseases in humans (Akhtar et al., 2020).
Photo from: Kadri et al., 2017
Studies indicate fungi have a powerful capacity to degrade PAHs due to their ability grow on numerous surfaces, excrete enzymes, and penetrate polluted soil to remove hydrocarbons (Kadri et al., 2017) (Park et al., 2020).
The rate and pathways of PAH remediation by fungi depend on environmental conditions, enzymatic activity, and fungal growth (Kadri et al., 2017).
Phanerochaete chrysosporium, Pleurotus ostreatus and Bjerkandera adusta fungal species are most commonly used for bioremediation of PAHs due to their production of ligninolytic enzymes (Kadri et al., 2017).
Pesticides and Herbicides
Chemicals in pesticides and herbicides are reported to be neurotoxic, carcinogenic, and detrimental to reproductive and organ systems. These chemicals runoff into water sources and enter the food chain, harming local plants, animals, and humans (Akhtar et al., 2020).
Photo from: Akhtar et al., 2020
Numerous studies have shown the ability of different fungi to remove pesticides and herbicides from the environment.
Aspergillus tamarii and Botryosphaeria laricina were able to degrade the insecticide "endosulfan" and it’s harmful metabolites (Silambarasan et al., 2013).
Aspergillus glaucus was able to degrade the insecticide "fipronil" and it’s metabolites (Gajendiran et al., 2017).
Enzyme extracts from Trametes maxima and Paecilomyces carneus were able to degrade 100% of the herbicide "atrazine" (Chan-Cupul et al., 2016).
Oils
Oil pollution from drilling or fueling accidents leads to dangerous environmental hazards which harm aquatic life, impact drinking water safety, and cause health hazards throughout the affected food chain.
Photo from: Dickson et al., 2019
Studies show the ability of fungi to clean oil-contaminated soils and aquatic ecosystems.
Arbuscular mycorrhiza, yeast, Penicillum, and Aspergillus species have been reported to successfully degrade crude oils (Dickson et al., 2019).
White-rot fungi shows a powerful ability to remediate petroleum-contaminated soils because they naturally feed on lignin, a substance with a similar structure (Dickson et al., 2019).
Trichoderma harzianum was shown to utilize diesel as a carbon source and remediate diesel-contaminated sand (Elshafie et al., 2020).
Plastics
Increased production of synthetic plastics has detrimental environmental effects due to their widespread disposal and lack of degradability (Khan et al., 2017).
Photo from: Khan et al., 2017
Studies have shown the potential of fungi to break down plastics and plasticizers in soils and aquatic ecosystems.
Aspergillus tubingensis was shown to degrade polyester polyurethane material by breaking chemical bonds (Khan et al., 2017).
White-rot fungi and other species have demonstrated the ability to break up polyethylene polymer chains (Cowen et al., 2021).
Enzymes from mushroom composts were able to remove phthalate plasticizers from wastewater through adsorption and biodegradation (Chang et al., 2021).
Pharmaceutical Waste
Toxic compounds released from drug manufacturing diminish clean drinking water sources and impact ecological, animal, and human health (Akhtar et al., 2020).
Photo from: Asif et al., 2017
Aquatic and white-rot fungi have been shown to remediate pharmaceutical waste.
Mucor hiemalis was able to absorb and degrade acetaminophen and diclofenac in aquatic environments (Esterhuizen-Londt et al., 2016).
The white-rot fungus Trametes versicolor has been shown to uptake and remove naproxen, ketoprofen, codeine, diazepam, carbamazepine, and metoprolol (Marco-Urrea et al., 2010) (Akhtar et al., 2020).
Various fungi have also been shown to remove antibiotics from ecosystems, which are otherwise resistant to physical and chemical removal methods (Gothwal et al., 2014) (Akhtar et al., 2020).
Future Directions
In many cases, the underlying mechanism behind the degradation and absorption of harmful pollutants by fungi is unclear and requires more research. Such studies may reveal specific genes or proteins involved in the mycoremediation process which may help expedite removal of pollutants from the environment.
Additionally, many studies have been conducted in bioreactors or laboratory settings and need to be investigated using indigenous fungi growing in polluted locations. Laboratory-developed fungal strains may behave differently in the environment and have adverse environmental effects. Therefore, more holistic ecosystem research needs to be conducted.
Nevertheless, there is substantial evidence that mycoremediation can help remediate environmental pollutants and improve the safety of this planet for future generations.
There is a need for policy development focused on funding for widespread implementation of mycoremediation strategies.
Such policies should specifically emphasize the importance of remediating pollutants among vulnerable populations.
Soil and water pollution disproportionately impact low-income communities and exacerbate health disparities.
Mycoremediation is a low-cost and highly effective method of removing harmful toxins from an environment which could help mitigate such disparities by improving environmental safety and community health in marginalized populations.
“The cascade of toxins and debris generated by humans destabilizes nutrient return cycles, causing crop failure, global warming, climate change and, in a worst-case scenario, quickening the pace towards ecocatastrophes of our own making. As ecological disrupters, humans challenge the immune systems of our environment beyond their limits. The rule of nature is that when a species exceeds the carrying capacity of its host environment, its food chains collapse and diseases emerge to devastate the population of the threatening organism. I believe we can come into balance with nature using mycelium to regulate the flow of nutrients. The age of mycological medicine is upon us. Now is the time to ensure the future of our planet and our species by partnering, or running, with mycelium.” - Paul Stamets, Mycelium Running: How Mushrooms Can Help Save the World (2005)
Photo by: Timothy Dykes on Unsplash
References
Akhtar, N., & Mannan, M. A. (2020). Mycoremediation: Expunging environmental pollutants. Biotechnology reports (Amsterdam, Netherlands), 26, e00452. https://doi.org/10.1016/j.btre.2020.e00452
Asif, M. B., Hai, F. I., Singh, L., Price, W. E., & Nghiem, L. D. (2017). Degradation of pharmaceuticals and personal care products by white-rot fungi—a critical review. Current Pollution Reports, 3(2), 88-103.
Azevedo-Santos, V. M., Brito, M., Manoel, P. S., Perroca, J. F., Rodrigues-Filho, J. L., Paschoal, L., Gonçalves, G., Wolf, M. R., Blettler, M., Andrade, M. C., Nobile, A. B., Lima, F. P., Ruocco, A., Silva, C. V., Perbiche-Neves, G., Portinho, J. L., Giarrizzo, T., Arcifa, M. S., & Pelicice, F. M. (2021). Plastic pollution: A focus on freshwater biodiversity. Ambio, 50(7), 1313–1324. https://doi.org/10.1007/s13280-020-01496-5
Chan-Cupul, W., Heredia-Abarca, G., & Rodríguez-Vázquez, R. (2016). Atrazine degradation by fungal co-culture enzyme extracts under different soil conditions. Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes, 51(5), 298–308. https://doi.org/10.1080/03601234.2015.1128742
Chang, B. V., Yang, C. P., & Yang, C. W. (2021). Application of Fungus Enzymes in Spent Mushroom Composts from Edible Mushroom Cultivation for Phthalate Removal. Microorganisms, 9(9), 1989. https://doi.org/10.3390/microorganisms9091989
Chaudhry, F. N., & Malik, M. F. (2017). Factors Affecting Water Pollution: A Review. Journal of Ecosystem & Ecography, 07(01). https://doi.org/10.4172/2157-7625.1000225
Cowan, A. R., Costanzo, C. M., Benham, R., Loveridge, E. J., & Moody, S. C. (2021). Fungal bioremediation of polyethylene: Challenges and perspectives. Journal of applied microbiology, 10.1111/jam.15203. Advance online publication. https://doi.org/10.1111/jam.15203
Dickson, U. J., Coffey, M., Mortimer, R. J., Di Bonito, M., & Ray, N. (2019). Mycoremediation of petroleum contaminated soils: Progress, prospects and Perspectives. Environmental Science: Processes & Impacts, 21(9), 1446–1458. https://doi.org/10.1039/c9em00101h
Elshafie, H. S., Camele, I., Sofo, A., Mazzone, G., Caivano, M., Masi, S., & Caniani, D. (2020). Mycoremediation effect of Trichoderma harzianum strain T22 combined with ozonation in diesel-contaminated sand. Chemosphere, 252, 126597. https://doi.org/10.1016/j.chemosphere.2020.126597
Esterhuizen-Londt, M., Schwartz, K., & Pflugmacher, S. (2016). Using aquatic fungi for pharmaceutical bioremediation: Uptake of acetaminophen by Mucor hiemalis does not result in an enzymatic oxidative stress response. Fungal biology, 120(10), 1249–1257. https://doi.org/10.1016/j.funbio.2016.07.009
Food and Agriculture Organization of the United Nations. (2018, May 2). Polluting our soils is polluting our future. Food and Agriculture Organization of the United Nations. Retrieved November 12, 2021, from https://www.fao.org/fao-stories/article/en/c/1126974/.
Gajendiran, A., & Abraham, J. (2017). Biomineralisation of fipronil and its major metabolite, fipronil sulfone, by Aspergillus glaucus strain AJAG1 with enzymes studies and bioformulation. 3 Biotech, 7(3), 212. https://doi.org/10.1007/s13205-017-0820-8
Gangadhar, Z. S. (2014). Environmental Impact Assessment on Soil Pollution Issue about Human Health. International Research Journal of Environment Sciences, 3(11), 78–81. https://doi.org/10.1.1.1074.6404
Gothwal, R., & Shashidhar, T. (2014). Antibiotic pollution in the environment: A Review. CLEAN - Soil, Air, Water, 43(4), 479–489. https://doi.org/10.1002/clen.201300989
Kadri, T., Rouissi, T., Kaur Brar, S., Cledon, M., Sarma, S., & Verma, M. (2017). Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by fungal enzymes: A review. Journal of environmental sciences (China), 51, 52–74. https://doi.org/10.1016/j.jes.2016.08.023
Kapahi, M., & Sachdeva, S. (2017). Mycoremediation potential of Pleurotus species for heavy metals: a review. Bioresources and bioprocessing, 4(1), 32. https://doi.org/10.1186/s40643-017-0162-8
Khan, S., Nadir, S., Shah, Z. U., Shah, A. A., Karunarathna, S. C., Xu, J., Khan, A., Munir, S., & Hasan, F. (2017). Biodegradation of polyester polyurethane by Aspergillus tubingensis. Environmental pollution (Barking, Essex : 1987), 225, 469–480. https://doi.org/10.1016/j.envpol.2017.03.012
Kumar, V., & Dwivedi, S. K. (2021). Mycoremediation of heavy metals: processes, mechanisms, and affecting factors. Environmental science and pollution research international, 28(9), 10375–10412. https://doi.org/10.1007/s11356-020-11491-8
Marco-Urrea, E., Pérez-Trujillo, M., Blánquez, P., Vicent, T., & Caminal, G. (2010). Biodegradation of the analgesic naproxen by Trametes versicolor and identification of intermediates using HPLC-DAD-MS and NMR. Bioresource technology, 101(7), 2159–2166. https://doi.org/10.1016/j.biortech.2009.11.019
Martinho, V. J. P. D. (2020). Exploring the Topics of Soil Pollution and Agricultural Economics: Highlighting Good Practices. Agriculture, 10(1), 24. doi:10.3390/agriculture10010024
Monroe, M. (2019). Fantastic Fungi. Netflix. Retrieved from https://www.netflix.com/search?q=fan&jbv=81183477.
Mycoremediation. Earth Repair. (2018, November 30). Retrieved December 2, 2021, from https://earthrepair.ca/resources/bioremediation-types/mycoremediation/.
Park, H., & Choi, I. G. (2020). Genomic and transcriptomic perspectives on mycoremediation of polycyclic aromatic hydrocarbons. Applied microbiology and biotechnology, 104(16), 6919–6928. https://doi.org/10.1007/s00253-020-10746-1
Sakshi, Singh, S. K., & Haritash, A. K. (2019). Polycyclic aromatic hydrocarbons: Soil pollution and remediation. International Journal of Environmental Science and Technology, 16(10), 6489–6512. https://doi.org/10.1007/s13762-019-02414-3
Silambarasan, S., & Abraham, J. (2013). Mycoremediation of endosulfan and its metabolites in aqueous medium and soil by Botryosphaeria laricina JAS6 and Aspergillus tamarii JAS9. PloS one, 8(10), e77170. https://doi.org/10.1371/journal.pone.0077170
World Health Organization. (2019, June 14). Drinking-water. World Health Organization. Retrieved November 12, 2021, from https://www.who.int/news-room/fact-sheets/detail/drinking-water.
Zwolak, A., Sarzyńska, M., Szpyrka, E., & Stawarczyk, K. (2019). Sources of soil pollution by heavy metals and their accumulation in vegetables: A Review. Water, Air, & Soil Pollution, 230(7). https://doi.org/10.1007/s11270-019-4221-y