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Mycoremediation is the use of fungi to break down or remove toxins from the environment.
Introduction to mycoremediation
Mycoremediation practices involve mixing mycelium (the vegetative part of a fungus) into contaminated soil, placing mycelial mats over toxic sites, or a combination of these techniques, in one or more treatments. The lead researcher in this field is mycologist Paul Stamets. The information presented in this document comes from his book "Mycelium Running -How Mushrooms Can Save the World".
Why use mycoremediation?
Fungi can be thought of as the primary governors of ecological equilibrium because they control the flow of nutrients. The strength and health of any ecosystem is a direct measure of its diverse fungal populations and their interaction with other organisms such as plants, insects, and bacteria. Using fungi as the starter species in a bioremediation project sets the stage for other organisms to participate in the rehabilitation process. Once toxic barriers are removed by specific mushrooms, a synergy between at least 4 kingdoms (fungus, plant, bacterium, and animal) enters the habitat and denatures toxins into derivatives that are useful to many species and fatal to few species. The introduction of a single fungus into a nearly lifeless landscape triggers a flow of activity by other organism and begins to replenish the ecosystem.
Mycoremediation is an economically and environmentally sound alternative to extracting, transporting and storing toxic waste. It restores value to depleted land. The current policy concerning toxic waste removal/clean up prescribes burning, hauling, and/or burying the waste. The results of these processes do not get rid of the waste or restore the ecology, but cripple it and leave it lifeless. Toxins in our food chain (including mercury, PCB's, and dioxins) become more concentrated at each step, with those at the top being contaminated by ingesting toxins consumed by those lower on the food chain. Mycelia can destroy these toxins in the soil before they enter our food supply.
Researchers have been able to customize strains of mushrooms to neutralize toxic weapons and waste. Research is being done to use mycoremediation in the field of national defense against chemical and biological warfare. This also births the opportunity to use mycoremediation to help mend war-torn environments.
How it works
Fungi are proficient molecular disassemblers breaking down long chained toxins into simpler less toxic chemicals. They remove heavy metals from land by channeling them to fruit bodies for removal. they essentially use and digest these toxins as nutrients. Mycelial enzymes can decompose some of the most resistant materials made by humans or nature, because many of the bonds that hold plant material together are similar to the bonds found in petroleum products including diesal, oil, and many herbicides and pesticides. these toxins also including textile dyes, estrogen-based pharmaceuticals and etc.. are vulnerable to enzymes secreted by the mycelia. some mushroom species can degrade several of these, while other are more selective.
The general method
The overall method of mycoremediation is quite simple: Overlay straw or woodchips infused with the right mycelium to create a 'living membrane of enzymes that will rain down' on the toxins in the top soil. Replenish annually with additional mycelium-treated substrate. Depending on the situation, several sequential applications may be the necessary norm to reduce toxins to acceptable levels.
There are various problems that are hindering the potential of mycoremediation. One problem is bioremediation projects that don't use mushroom mycelium as a starter species, thus offshooting the 'domino effect' of biological decomposition. There is also a large legal issue. There are several issued patents specifically granted for matching fungus against a toxin. This is a major stumbling block preventing wide-scale fungal clean-up of toxins. A problem with mycoremediation trials themselves, is the lack of experienced mushroom cultivators in outdoor trials. This lacking has affected the success of several trials.
Mushroom enzymes break down many chemical contaminants, but they can also concentrate heavy metals. If a site also contains heavy metals, the mushrooms should not be eaten. Know where your mushrooms come from!
"Mycelium Running" Paul Stamets. 2005. Berkeley, CA. Ten Speed Press
--Here is a group who are mycoremediating an oil spill in the Amazon river in Ecuador
--In Fort Bragg, CA. the town council gave permission to mycoremediate a contaminated old mill site as an alternative to transporting the soil elsewhere. If this is successful is will be encouraging for the utilization of mycoremediation in the future
--A great resource