Imagine all the plastic trash you accumulate from one trip to the grocery store, from water bottles and children’s toys to clamshell containers and cosmetic microbeads. Now imagine enough trash to equal the weight of one billion elephants, and you’ll have some sense as to the amount of plastic we’ve discarded since the 1950s.
Plastics are now humanity’s number one source of pollution, accounting for 20-30 percent of landfill volume worldwide, while an additional 12 million metric tons are dumped annually into our oceans. As each piece can take millennia to decompose completely, our discarded plastics form vast trash islands called “gyres”—there’s even one the size of Texas—where marine species mistake the toxic, increasingly-microscopic particles for plankton and other food sources.
With plastic consumption still on the rise, it’s a fast-compounding problem no one quite knows how to solve, but Peter McCoy is one of many who believe the answer has been under our feet the whole time. “Plastics have been known as susceptible to fungal degradation since they were first manufactured over 100 years ago,” explains McCoy, who founded the grassroots research organization Radical Mycology, which advocates for underutilized applications of mushrooms and other fungi.
Maybe the most underutilized of all is a process called mycoremediation, whereby fungi are used to decontaminate the environment. Distinct from plants, animals and bacteria, fungi are responsible for 90 percent of all decomposition on Earth, and their natural talent for colonizing and breaking down compounds too complex for other organisms has been harnessed to clean up manmade toxins such as TNT, herbicides, synthetic dyes and, yes, even plastic.
McCoy explains how early plastics manufacturers tested their products’ longevity by burying pieces in the ground to see what would happen. After digging the plastic up, experimenters discovered colonies of fungi beginning to naturally digest the decidedly-unnatural substance. So why aren’t we already spraying our plastic-clogged landfills with mushroom spores? “That applies to so much of mycology,” laments McCoy. “We know they have this potential, so why hasn’t it taken off?”
In much of the West, and particularly in the U.S., mushrooms are little-understood and often even feared, which is why Radical Mycology makes disseminating knowledge about their many uses a priority. The research is often there, but not the public awareness and acceptance necessary to make an impact.
So it goes with plastic remediation. Our understanding has come a long way since 2012, however, when a group of Yale students noticed one of their fungal samples from the Amazon was eating the plastic petri dish around it. Pivoting in their research, they discovered this random fungus—an endophytic form that occurs only inside plants—could survive with plastic as its sole food source, even in oxygen-deprived environments like landfills.
Before this, one of the biggest roadblocks to plastic remediation was that other fungal species wouldn’t decompose as rapidly in isolation, but instead worked best together, with numerous species fulfilling different functions throughout the decomposition process. Endophytes may be one of the most diverse and mysterious of all fungal niches, so the Yale students’ discovery has kicked off a new wave of interest in this previously neglected branch of mycology.
Endophytic fungi may have inherited this supercharged decomposing ability from their lichen ancestors, known for degrading even volcanic rock with their digestive enzymes for a food source. McCoy speculates that focusing on lichen-derived genera of fungi like Penicillium and Aspergillus may thus provide the best path forward for mycoremediating plastics on a larger scale.
But there are many variables in cultivating mushrooms outside of a controlled environment. Thus, McCoy posits, it may be most effective to grow fungi in a lab and isolate their digestive enzymes separately, then spray high concentrations on landfills and floating gyres. Cultivators can even “train” a mushroom to create stronger, specialized enzymes by giving it increasing concentrations of the targeted pollutant—i.e., plastic—to consume.
Mycology may still be neglected compared to other sciences, but its usefulness in combatting our plastics problem and other environmental crises has become increasingly evident in the past five years. It just remains to be seen how and when humanity will put our new fungal knowledge to good use. “I have high hopes,” assures McCoy, “that someone—whether it’s an academic, private company, or some guy in his garage—will come up with the best way to break down plastics.”