By: Evelyn Pae
Fungi are one of the most peculiar and mysterious kingdoms sprouting on the tree of life. They can grow in locations as remote as the ocean depths or as personal as the nooks between your toes. It is estimated that that millions of species of fungi remain unknown to science. However, even the most common species of mushroom can conceal extraordinary properties. Several types of fungus, like the oyster mushroom, have the ability to pull heavy metals and other toxins from the soil. This property has many potential applications in land restoration and toxicology. (4) (6)
Mycoremediation is the name given to the practice of using fungi to cleanse soil or aquatic environments. (8) Several studies have already shown promising results in this field. (1) (5) (7) In one 2015 research trial, 7 out of 15 strains of mushroom proved their ability to draw arsenic from contaminated soil, which had positive effects on plant growth. Arsenic contamination is an agricultural problem in the United States. (7) Toxins in soil can reduce crop production, and accumulation of toxins in the crops can negatively affect human health.
Some types of fungi can also be used to degrade chemical compounds that enter the environment as a byproduct of industrial activity. Pleureotus ostreatus can degrade polycyclic aromatic hydrocarbons (PAHs) polluting soil, increasing the germination rate of mustard seeds in one mycoremediation study. (1) PAHs are found in coal residues and can have carcinogenic effects on living organisms. Mushrooms, occupying the decomposer role in ecosystems, naturally process these organic molecules. Oyster mushrooms’ ability to absorb toxins from fossil fuel pollution could also be useful in ecosystem restoration, such as in the use of mycobooms to clean up oil spills. (8)
P. ostreatus can also absorb antibiotics that are released by concentrated animal feeding operations, livestock centers at which high levels of antibiotics are administered to animals in order to artificially sustain the unsanitary living conditions there. Environments contaminated with antibiotic medication are breeding grounds for new strains of antibiotic-resistant bacteria, creating a public health concern. The ability of P. ostreatus to absorb one such antibiotic, a chemical named oxytetracycline commonly used to treat skin conditions or lung infections, was successfully tested in 2012. (5)
While mycoremediation is a promising field of bioremediation studies, the tendency for fungi to accumulate toxins in their fruiting bodies can be a problem when it comes to the human consumption of mushrooms. Because of the high levels of heavy metal and fossil fuel pollution in today’s environment, some mushrooms must be consumed with caution. (2) Mushrooms—as a source of fiber, many key vitamins, and protein—are an important food source that occupies a different growing niche from most conventional crops today. By further studying fungal bioaccumulation, important knowledge for both land restoration and nutrition can be obtained from these vital decomposer organisms.
- Bhatt, M., Cajthaml, T. & Šašek. “Mycoremediation of PAH-contaminated soils.” V. Folia Microbiol (2002) 47: 255. https://doi.org/10.1007/BF02817647.
- Chatterjee, S., Sarma, M.K., Deb, U. et al. “Mushrooms: from nutrition to mycoremediation.” Environ Sci Pollut Res (2017) 24: 19480. https://doi.org/10.1007/s11356-017-9826-3.
- Kalač, Pavel. “A review of trace element concentrations in edible mushrooms.” Food Chemistry. 15 May 2000.https://www.sciencedirect.com/science/article/pii/S0308814699002642.
- Kulshreshtha, Shweta, et al. “Mushroom as a product and their role in mycoremediation.” AMB Express. PMC. 1 Apr. 2014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4052754/.
- Migliore, Luciana, et al. “Biodegradation of oxytetracycline by Pleurotus ostreatus mycelium: a mycoremediation technique.” ScienceDirect, Elsevier B.V., 1 March 2012, https://www.sciencedirect.com/science/article/pii/S0304389412002130.
- Rhodes, Christopher J. “Mycoremediation (bioremediation with fungi) – growing mushrooms to clean the earth, Chemical Speciation & Bioavailability, 26:3, 196-198, DOI: 10.3184/095422914X14047407349335.
- Singh, M. et al. “Soil fungi for mycoremediation of arsenic pollution in agriculture soils.” Journal of Applied Microbiology. Society for Applied Microbiology. 21 Oct. 2015. https://onlinelibrary.wiley.com/doi/abs/10.1111/jam.12948.
- Stamets, Paul. “The Petroleum Problem.” Fungi Perfecti, Fungi Perfecti, 3 June 2010, fungi.com/blogs/articles/the-petroleum-problem.