Can Fungi Save the Planet?
One time I was at a party and a mushroom walked in. The lady next to me leaned over, pointed at him, and said, “Hey, I’ve heard he’s a fun guy!” I’m sure you’ve all heard that one before, and if you haven’t, you’re welcome. There’s a brand new conversation starter.
The cheesiness of this middle school joke aside, fungi really are great. Scientists have discovered that some of the natural processes performed by fungi have the potential to help clean up our environment, a concept termed mycoremediation. Although this is a relatively new approach to environmental remediation, many ecologists and mycologists have already started collaborating and conducting research to develop the idea.
Here’s how it works. Agricultural, fossil fuel, and manufacturing industries generate huge amounts of waste— often in the form of toxic chemicals or other hazardous materials— that end up bioaccumulating as pollutants in the environment. Fungi naturally produce enzymes that allow them to metabolize and process complex molecules, including some of these pollutants. The way fungi accomplish this and what happens to the pollutants afterwards varies depending on the fungal species and the pollutants being metabolized. The three primary modes of mycoremediation are biodegradation, biosorption, and bioconversion.
Biodegradation occurs when fungi break down complex molecules into simpler ones that the environment is better equipped to deal with. Toxins are less polluting and less environmentally persistent after they’ve been metabolized and degraded by fungi. Biodegradation is thought to work best when restoring aquatic ecosystems that have been contaminated with crude oils or other petroleum products, such as the gnarly oil blob in the photo below.
Biosorption is a process in which fungi actually absorb pollutants from the environment. This tends to work best when the pollutants are heavy metals, which is often the case when we’re dealing with degraded soils. When a fungal species is placed in a contaminated environment, it will chemically bind to any nearby pollutants and transport them into its own cells. Fungi have a pretty high capacity to absorb pollutants in this way and don’t require additional metabolic energy to do so.
Like biodegradation and biosorption, bioconversion is named after the process it describes. This is when fungi are used to convert environmental toxins into edible organic matter. What’s crazy about bioconversion by fungi is that the process yields… mushrooms! Yep, you read that correctly. Mushrooms making mushrooms and remediating nature while they’re at it. Cool, right? Fungi use their enzymes to produce what are called mushroom “fruiting bodies” that can be consumed as a source of protein.
The general idea behind the science of mycoremediation is to introduce fungi to polluted environments, such as soils saturated with heavy metals or rivers contaminated with petroleum oil, and give the fungi a chance to degrade the toxins naturally. The key word here is naturally. When humans are tasked with cleaning up oil or chemical spills in the environment, the side effects can be problematic. For one thing, this clean up work requires tons of energy to power all of the associated tech and machinery. It also tends to disrupt the environment around the clean up site, which leads to further ecological imbalances. Allowing fungi to take on some of this work naturally (through mycoremediation processes) helps to minimize any additional environmental damage to a polluted area.
One example of a mycoremediation project that’s close to my heart was done in Humboldt County, California, which is where I spent all eighteen years of my life before moving to Berkeley for college. Humboldt County sits in a rural pocket of northern California and through it runs the Klamath River, a waterway that’s extremely important to its surrounding ecosystems. When a diesel fuel spill contaminated part of the Klamath in the town of Orleans, a small local business called Fungaia Farm was called upon to help restore the area using mycoremediation. The team developed a treatment plan using fungi that break down petroleum molecules quickly and effectively, and they eventually managed to remediate the entire area! The bar chart below, which you can find in their published project report, shows drastic decreases in the pollutant concentration of soils treated with fungi compared to those that were untreated. In other words, these fungi really did clean up a contaminated environment!
Although mycoremediation is still a fairly recent concept, it seems to be a hopeful one. As scientists continue to develop strategies for environmental restoration, it’s important that we invest research and funding in methods that will not only fix the problems we’ve created, but also refrain from creating new ones! Since fungi have the potential to do this naturally, they seem like a pretty good candidate for soil and aquatic clean up projects in the future. Who knows? Maybe one day I’ll be at a party, a mushroom will walk in, and the lady next to me will lean over and say, “Hey I’ve heard he’s a fun guy and he saved the planet!”
If you love a good TED Talk, check out this video of mycologist Paul Stamets explaining 6 ways mushrooms can save the world!