Coffee grounds, an invasive tree called Casuarina, biodiesel byproducts, and gourmet mushrooms — How are these four, seemingly disparate items related? As part of the Center for Sustainable Development’s 2019 mycoremediation initiative, spent coffee grounds, sawdust, glycerol, and mycelium* are being used to help close the loop of waste produced at The Island School, while simultaneously increasing food security.
Building off of glycerol waste and mycoremediation research by intern Kelly Rhodes (summer ‘18), CSD’s Energy Team is implementing systems that use fungal networks to reverse and stop environmental damage on campus. Specifically, mycoremediation will provide a sustainable waste management system for petroleum residues and glycerol that is produced as a byproduct of the biodiesel synthesized on campus.
Fungi are unique in their ability to break down various contaminants, such as pesticides and petroleum products, via the secretion of extracellular enzymes. They detoxify and convert these contaminants into sugars to be absorbed by themselves and other decomposers. Without fungi, nutrients are unable to be recycled into soils that foster healthy ecosystems.
Currently, experimentation being carried out by the Energy Team will demonstrate the fungi’s ability to adapt, and then utilize soil pollutants to thrive and propagate. In order to optimize the mycoremediation results, the team is testing which contaminants (crude glycerol, biodiesel, and motor oil) the fungal species, Pleurotus ostreatus (Oyster mushroom), is most efficient at digesting, and which substrates (coffee grounds, Casuarina wood shavings and sawdust) allow its mycelium to thrive.
Once it has been determined which strains are most successful in various environments, substrates will be inoculated with the adapted mycelium and encouraged to propagate. The hope being that glycerol can be utilized as a food source for fungi, which will, in turn, remediate polluted soils and create nutrient rich environments to recruit healthy soil bacteria and native flora and fauna.
Moving forward, this research will be continued as a Spring 2019 Island School research course where students will help analyze and monitor soil health around campus. A secondary component of the students’ work will be designing a mushroom farm, which will grow Oyster, Shiitake, and Lion’s Mane mushrooms — all edible gourmet varieties — for community consumption. The vision is to set-up and expand sustainable intensive cultivation methods, such that weekly harvests can be supported.
This aspect of mycology addresses the project’s, and CSD’s overall mission to increase food security. Mushrooms can be grown on minimal inputs, such as coffee grounds, seaweeds, and sawdust. As such, they’ll serve as a way to close the loop on organic waste produced on campus, and as a benefit, provide a more diversified and nutrient-dense vegan protein source. Overall, we seek to prove the possibility of producing a more sustainable, and locally-sourced alternative to soy-based options currently offered.