Mycoremediation

Branched Oyster Mushroom 02
Fungi are powerful planetary healers and disaster responders. They are Nature’s decomposers, responsible for breaking down most of the Earth’s plant and woody material into life giving soil. Just like they break down complex carbon based plant cell structures, like cellulose and  lignin, saprophytic fungi use their digestive enzymes to break down chemicals like hydrocarbons and pesticides. Fungi can break down larger hydrocarbon chains into smaller pieces, allowing for microorganisms and plants to get to work. Fungi can also extract and hyperaccumulate heavy metals, concentrating them in the fruiting body of the fungi (what we know as the visible mushroom).
Using fungi for bioremediation and earth repair requires a large amount of mycelium. Mycelium refers to the ultra-fine and dense network of branching thread-like white hyphae that is the vegetative part of the fungi. It is the mycelia that send out the enzymes that break down chemicals, and that also act as a filter, among many other things. In order to do effective bioremediation work and mycoremediation installations, a lot of mycelium is needed, and this can be challenge to most grassroots bioremediators. Mycellium can be bought, donated from mushroom farms, or you can learn how to grow your own mushrooms.
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From layering mushrooms spawn with contaminated soil and wood chips, to installing mycofilters to trap contaminants in runoff and polluted water, there are many different ways to apply mushrooms to earth repair. Grassroots mycoremediators can install mushroom beds to deal with contaminated soil, decrease erosion, and  help recharge and heal damaged land.
Mushrooms can be added to your grey water system. Mycelliated straw can be used to absorb spilled oil. Mycobales can be made from straw bales inoculated with mushroom spawn, and placed in the path of polluted runoff or a contaminated stream.
Burlap sacks can be stuffed with straw, cardboard, coffee grounds, and mushrooms spawn, and similarly used to intercept and filter contaminated water.

Credit: Paul Stamets

A few of the common fungi used in remediation, and some of the contaminants they work on are:
  • Shaggy Mane: Arsenic, cadmium, and mercury
  • Elm Oyster: Dioxins, wood preservatives
  • Phoenix Oyster: TNT, cadmium, mercury, copper
  • Pearl Oyster: PCB’s, PAH’s, cadmium, mercury, dioxins
  • King Oyster: Toxins, Agent Orange
  • Shitake: PAH’s, PCB’s, PCP’s
  • Turkey Tail: PAH’s, TNT, organophosphates, mercury
  • Button Mushrooms: Cadmium
  • King Stropharia: E-coli and other biological contaminants
Most of us know a bit about growing plants. However, when it comes to cultivating mushrooms, we have little experience or training. In order to be effective mycoremediators, we need to understand some basic mycology and know how to cultivate  and care for mushrooms.
Your mushrooms and mycoremediation installations will need moisture, shade, air and the right temperature to grow. Different mushrooms can handle different temperature ranges. One of the biggest mistakes beginners make is to not provide adequate moisture or shade to their mushrooms – you don’t want your mushrooms to dry out or fry under the hot sun.

Also, different species of mushrooms are effective at remediating different contaminants. Different strains of that species can be more effective than others. Some mycoremediators actually train their mushrooms strains to eat a particular contaminant.

Some species of fungi like to be left undisturbed to do their work, others thrive on agitation. Different species of mushrooms require different things to grow on and eat. Some grow best in logs, others on wood chips, cardboard, corn cobs, cotton rags, burlap sacks, and more. These materials are called the substrate.

 

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The wood chips used should be well hydrated, and should be fairly fresh – between 2 weeks to 2 months old. If they are too old, they will likely have many other competitor fungal species in them, making it hard for your mushroom to grow. Different mushrooms like different types of wood – some like alder and maple. Some like oak and douglas fir. Hardwoods are preferred, and anti-fungal species like cedar should be avoided.
Get to know the local mushrooms in your area – it is always better to work with local mushrooms species and strains. Learn grassroots mycocultivation techniques that allow you to grow mushrooms from spore and tissue samples – that way you won’t have to buy your spawn and have it shipped to you. Build relationships with different organic mushrooms farms, who may let you have their spent mushroom spawn for your remediation and earth repair projects. Connect with local arborists so that you can get fresh wood chips and logs sent your way to inoculate with mushrooms.
Finally, become acquainted with the many healing properties of mushrooms – not only do they help bind, extract and transform contaminants in the land as well as retain water in the soil, they also are powerful healers for us humans. From powerful immune boosters to cancer fighters, they have much to offer to us all!

More detailed information on grassroots mycocultivation and mycoremediation techniques and projects can be found in Earth Repair. There are also some great grassroots mycoremediators who offer courses, as well as gatherings like the Radical Mycology Convergence, where many skills can be learned – their information can be found in the Helpful Links section of this website.