Bit of a tongue-twister, isn’t it? Coined by Paul Stamets, it’s derived from the Latin remedium, re- ‘back’ or ‘again’, mederi ‘heal’, and from the Ancient Greek myco- which relates to all things fungi. Essentially, Mycoremediation concerns how we can use fungi as a remedy, to reverse environmental damage.
But how can we heal all the harm already done? Mycoremediation is a form of bioremediation: using enzymes produced by mushrooms, instead of bacteria, to break down pollutants and restore balance to the ecosystem. As Merlin Sheldrake puts it: “radical mycological solutions are less about inventing or learning than remembering”. Essentially, fungi won’t produce enzymes they don’t need; as such, metabolic pathways can lie dormant in fungal genomes for generations. A fungus will have to unearth forgotten pathways, often with a bit of encouragement from mycologists, in order to enzymatically break down pollutants.
So how can we use fungi to decontaminate environments?
One key player in mycoremediation is pleurotus, or white rot fungi, which fruits into the much-loved oyster mushroom. Researchers in Mexico City have found that introducing used diapers to pleurotus mycelium can, over 2 months, result in a 85% reduction in mass, compared to 5% in fungi-free control.
Edible oyster mushrooms - healthy and free from human diseases - grew from this waste. This is significant as used diapers make up 5-15% by weight of solid waste in the city. And even with the plastic of the diapers left on, there was still a reduction of 70% in mass (Espinosa Valdemar et al. 2011). Plus, the disposal of waste via enzymatic combustion reduces the amount of waste thermally combusted and thus improves air quality.
Pleurotus mycelium can also be trained to digest cigarette butts – of which 750,000 tonnes are thrown away every year. While unused cigarette butts break down over time, used ones are too saturated with toxins.
If that wasn’t enough to convince you of their superpowers, they also eat plastics… You heard right! Katharina Unger, Austrian designer, and the microbiology faculty at Utrecht University, NE, collaborated on a project that show Pleurotus ostreatus breaking down plastic and turning it into human-grade food within days!
Metal pollution can also be remediated mycologically. Through the process of biosorption, Agaricus bisporus, Fomes fasciatus, Pleurotus platypus, and Calocybe indica can help clean up elements such as copper, zinc, iron, cadmium, and heavy metals wastes. In order to generate absorption of metallic pollutants, biosorbents are developed using mushroom mycelium or mushroom compost (dead biomass). This method is not only efficient and effective, it’s low-cost too.
There’s even research showing how Antarctic Fungi species can assimilate and degrade compounds found in crude oil and refined petroleum. Yes, that’s right! Fungi can clean up oil spills and help restore the ecosystem’s balance.
Fungi’s ability to persist through five previous major extinction events on this planet just goes to show their powers of remediation and that we would be remiss to ignore them as we face the sixth. There is so much untapped potential in the Fungi Kingdom, and it presents us with hope when facing the many challenges of the 21st century. Let’s heal the planet, with fungi as our teachers and allies.