Mushrooms are not only delicious but also rich in various minerals, earning them the title of “superfood.” However, a new study suggests that the waste generated during the growth of mushrooms may have surprising sustainable applications.
According to CNBC, researchers at Utrecht University in the Netherlands have found that the residue left behind during the cultivation of white mushrooms can be used for water purification.
One of the researchers from the study, Brigit van Brenk, explained to CNBC over the phone, “The benefit of this waste stream is that it has low value, so we can make it more valuable.”
In a study published in April, the research team explained that white mushrooms are fungi that produce lignin-degrading enzymes. Lignin is a complex polymer present in the cell walls of almost all land plants, acting as a natural, highly adhesive binder. These enzymes have also been shown to break down other substances.
The researchers observed that in the Netherlands, the substrates left behind during mushroom harvesting were not fully utilized and were mostly transported to Germany for use as fertilizer. Acting as a medium for mushroom cultivation, the substrate functions similarly to soil for plant growth.
Taking this into consideration, the researchers decided to test the efficacy of mushroom substrate in removing pollutants from water. They added eight substances to water, including herbicide chemicals, caffeine, and pharmaceuticals, and then mixed them with substrate fragments.
They found that within 7 days, up to 90% of organic micropollutants had been removed from the water.
A study published last year indicated ongoing research revealing over fifty chemical substances, including pharmaceuticals and pesticides, detected in seawater near the southern coast of England by researchers from Brunel University London and the University of Portsmouth.
The European Investment Bank’s 2023 report emphasized that traditional wastewater treatment methods cannot completely remove micropollutants. The report also noted that the cost of implementing additional treatment to reduce micro-pollutant levels in water is “significant.”
In April, EU legislators approved new measures for urban wastewater treatment. This includes introducing the “polluter pays principle,” meaning cosmetic and pharmaceutical manufacturers must bear the additional costs of treating micropollutants.
In another study co-authored by Van Brenk and published in May, it was found that a “tea” made from mushroom substrate and soaked substrate could remove textile dyes from water.
Examples of fungi decomposing other pollutants in the environment have also brought hope to humans, a practice known as “mycoremediation.”
For instance, fungi have been used in the Amazon rainforest to clean up oil spills. In Sonoma County, California, a grassroots group turned to oyster mushrooms to remediate toxins in the environment following a wildfire. In New Zealand, researchers utilized fungi to treat soil contaminated with pentachlorophenol pesticides.
Some innovative companies are already utilizing the biodegradation abilities of mushrooms to design waste treatment solutions. The U.S.-based Mycocycle company uses fungi to consume and eliminate toxins in industrial waste, converting them into low-carbon materials.
Swedish startup MycoMine operates a facility that decomposes pollutants using fungi, generating biomass as an organic material that can be used for renewable energy.
Global data platform Dealroom informed CNBC that in the past five years, 139 fungal mycelium technology startups have collectively raised $2.5 billion in funding.
Van Brenk plans to establish a company with mushroom substrate as its main product.
“Our water is our primary source of life… If we destroy our rivers, then we may also be destroying our drinking water resources,” she said. “So, I think this is one of the social issues we are all facing now.”