Cleaning Up Pollution With Fungi

It’s no news that rapid industrialization has caused numerous environmental problems. Our most densely populated areas are cities of concrete and glass, where the sky is coated gray from car exhaust, and man-made lights replace stars for miles. In rural areas, drugs used in farming to treat diseases in the livestock leak into the water and soil, contaminating and negatively affecting all surrounding ecosystems, including the microbial communities (1). Furthermore, our water and soil are becoming increasingly contaminated with toxic metals, which are also detrimental to their respective ecosystems, as well as a high risk to human health (2).

Environmental contamination caused by industrial waste reduces the quality of the environment, and therefore the quality of life for all organisms. Traditionally, the issue of contamination has been approached by moving the contamination elsewhere, generally to landfills. Of course this does not actually fix the problem, it just gets rid of it in its original setting. Another method that has been used is destroying or transforming the contaminants to a harmless form via chemical decomposition (3). It isn’t hard to see how this method isn’t a great approach either; adding more chemicals to the mix causes further contamination.

The best alternative is bioremediation, and particularly mycoremediation. Bioremediation uses microorganisms that are already part of their environments to clean up pollution. Mycoremediation more specifically uses fungi. These fungi eat organic pollutants. Through the use of fertilizers and enhanced conditions, they grow more rapidly, and therefore breakdown the pollutants at a faster rate. This is a considerably better approach to solve the problem of environmental contamination.

Unfortunately, the field of mycoremediation has not been able to expand enough to be applied in practice. This is mainly due to the lack of funding for the field. The few studies that have been conducted on mycoremediation have all yielded successful results, which indicates that this is indeed a promising field of study. Funding for research in mycoremediation is crucial, for it is potentially one of the most preferable solutions to environmental contamination.

Fungi achieve the digestion of the contaminants by secreting extracellular enzymes that breakdown organic waste (4). A good example of the success of mycoremediation is seen in a study by Migliore et al. on the biodegradation of oxytetracycline by Pleurotus ostreatus. Oxytetracycline (OTC) is a drug that is heavily used on livestocks in intensive farming to treat diseases. Due to animal waste disposal, OTC contaminates water, sediments and soil, negatively affecting microbial community structures and natural systems. They cultured Pleurotus ostreatus with exposure to varying concentrations of OTC, and measured mycelial growth, extracellular enzyme secretion, and the degradation of OTC. Their results demonstrated that P. ostreatus survived and successfully grew even when exposed to high concentrations of the drug. While no OTC degradation was observed in the controls, P. ostreatus almost completely degraded the drug in a few days (1).

Valentin et al. conducted a study on the mycoremediation of contaminated wood and soil samples that was similarly successful. In order to really reflect the conditions of the setting their results would have potential use in, they used non-sterile conditions in their experiment. With the intentions of investigating white-rot and litter-decomposing fungi to treat contamination by chlorinated phenols present in sawmills, they inoculated non-sterile soil and wood — meaning the soil and wood had native microbial communities along with contamination — with nine fungi. The litter-decomposing fungus, Stropharia rugosoannulata, mineralized and degraded multiple contaminants at a significantly faster rate than indigenous microbes in soil. Therefore, S. rugosoannulata is a suitable fungus for mycoremediation of soil contaminated with chlorophenols. In wood, white-rot fungi grew and degraded contaminants faster than both indigenous degraders (which were barely present), and litter-decomposing fungi. These results show that S. rugosoannulata has particularly high potential to be used in mycoremediation of specifically sawmills containing chlorophenols (5). This study displays successful fungal growth as well as high degradation success in realistic conditions. It also pushes to further investigate the understudied litter-decomposing fungi for mycoremediation. Funding for more studies of this kind are necessary to improve our understanding of specific fungal interactions with contaminated environments.

Both these studies indicate successful usage of fungi in cleaning pollutants. Because this is a field that leans towards experimentation in rather specific contexts, thorough research must be done in a variety of contexts in order to ensure its applicability to real-life scenarios. However, the experimentation that has been done clearly shows the potential of mycoremediation. Even studies that have been done indicate the necessity for further research in the field in order to start applying their results in real life. Environmental contamination decreases the life quality of all organisms, and using fungi as remedies for our environment is a sustainable, natural, and affordable solution. With sufficient funding, this field could grow and become the number one cure for environmental pollution.

1.     Migliore, L. et al., “Biodegradation of oxytetracycline by Pleurotus ostreatus mycelium: a mycoremediation technique.” Journal of Hazardous Materials. 215-216, 227-232, 2012.

2.     Sharma, A., Sharma, H., “Role Of Vesicular Arbuscular Mycorrhiza In The Mycoremediation of Heavy Toxic Metals From Soil.” International Journal of Life Sciences Biotechnology and Pharma Research. 2, no. 3, 418-427, 2013.

3.    Vidali, M. "Bioremediation. An Overview*." Pure Applied Chemistry 73, no. 7, 1163-172. IUPAC, 2001.

4.     Adenipekun, C. O., Lawal, R. “Uses of mushrooms in bioremediation: A review.” Biotechnology and Molecular Biololgy Review, 7, no. 3, 62-68. Academic Journals, 2012.

5.     Valentin, L. et al., “Mycoremediation of wood and soil from an old sawmill area contaminated for decades.” Journal of Hazardous Materials. 260, 668-675, 2013