The pollution in our environment is growing exponentially from our incessant use of petrochemicals, dyes, paper and heavy metals increasing our exposure to dangerous chemicals at an alarming rate. Cleaning up our contaminated soils and waterways has been a challenge both physically and financially and the need for a natural solution to reverse the course is imperative.
Mycoremediation stems from the words myco (Greek for fungus) and remediation (reversing environmental damage), a term used to describe the use of fungi in degrading contaminants and toxins from the environment. Mycoremediation is a promising approach in environmental cleanup that is yielding remarkable results worldwide.
Fungi are the world’s great decomposers and the only microorganisms able to break down wood. By secreting enzymes and using their natural digestive ability, they are able to degrade complex compounds such as lignin and cellulose (essential components of plants) into simple molecules without any detrimental effect. Interestingly, lignin is very similar in structure to many heavy toxins such as crude oil which explains why some fungi are so effective in eliminating contaminants from polluted systems.
Mycoremediation has been effective in the following areas:
Coli and Salmonella are bacteria that can cause severe digestive illnesses usually as a result of contaminated water from infected human and animal feces. In this case, mycoremediation involves creating biofilters using mycelium (the vegetative part of the fungus) grown on straw or wood chips and placing them near livestock farms and shoreline plantings where runoff occurs. Runoff is retained long enough to allow the mycelium to consume the bacteria, preventing further contamination.
Aromatic pollutants (toxic components of petroleum), pesticides and herbicides are persistent contaminants that accumulate and spread up the food chain causing cancer and other chronic diseases. Mycoremediation entails introducing saprophytic (wood eating) fungi that break down these contaminants into carbon dioxide and water. One successful method includes placing mycelial mats over toxic sites and once the pollutants are dismantled by fungi, other organisms become active and denature toxins.
Industrial waste is the greatest source of pollution infiltrating our drinking water, soils and the air we breathe presenting a threat to human health as well as our natural resources and wild life. Mycoremediation involves stabilizing brown fields (contaminated sites) by decomposing carcinogenic compounds before they leach into our water system. Industrial run off can be captured by mycelium mats, radioactivity can be absorbed by some fungi and heavy metals can be consumed by mushrooms which are then harvested and disposed of. In order for mycoremediation to be successful, the right fungi must match the targeted contaminant.
The following is a short list of fungi varieties and some of the contaminants they denature:
|Shiitake, turkey tail||Wood preservatives, herbicides|
|Oyster mushroom, turkey tail||TNT|
|Oyster, shiitake, maitake||PCBs|
|Oyster, shiitake||Hydrocarbons (crude oil, natural gas etc)|
|Psylocibe spp., turkey tail||Persistent Organophosphates (Pesticides)|
|King oyster, oyster, Turkey tail||Dioxins (herbicides, paper bleach etc)|
|Turkey tail||Anthracene (coal tar)|
Mycoremediation is only one step in the complex process of bioremediation but one that is important in stabilizing contaminated environments and restoring habitats. The advantages of mycoremediation are that it is natural, safe, low maintenance, reusable, cost effective and fast. Though we continue to pollute our environment, our habits are changing, laws protecting our natural resources are being implemented and our resolve to clean up toxic sites is determined. Mycoremediation is a viable option that appears to have little, if any, detrimental effect that should become part of our environmental protection strategy.
Sources: Mycelium Running: How mushrooms can help save the world, Stamets, 2005, Magical Mushrooms: Mycoremediation, Frost & Sullivan 2002, resilience.org, Chris Rhodes, mushroomsmountain.com/bioremediation, radicalmycology.com, epa.gov