Can Mushrooms Rescue the Gulf?
For more than a decade, mycologist and inventor Paul Stamets has known that mushrooms eat oil. There were still a few kinks to work out; bringing the technology to scale and winning the acceptance of government agencies were two of the most challenging. Yet the basic science was solid and had been replicated many times by other scientists.
Then Stamets heard about the Deepwater Horizon oil spill in the Gulf of Mexico. While his first reaction was horror and regret, he also knew that he might be able to offer practical solutions, while at the same time giving his oil-eating mushrooms a chance to show their stuff.
He wasn’t the only one who thought mushrooms might be part of the solution. In the days after the explosion in the Gulf, the EPA contacted him several times to request a proposal. They wanted to understand how mycoremediation—the reduction of toxic compounds into harmless ones by fungi—could work as a component of their cleanup strategy for the spill.
Stamets drafted a three-page proposal and sent it off. Then he ramped up the pace of his research and shifted his focus to finding oil-eating mushrooms that could tolerate the Gulf of Mexico’s salt water and powerful sun.
Spokesman for a Kingdom
Stamets is a bit of a rogue scientist. He began his career in the forest as a logger, not as a scientist, and holds no degree higher than a bachelor’s from the Evergreen State College. Yet he has published three of the most widely read books on the art of growing and using fungi, founded a unique biotechnology company that now employs 37 people, and appeared in films and on talk shows to praise the talents of the powerful and mysterious fungal kingdom.
In fact, polishing the public image of fungus may be more important for Stamets than any decision to bring mushrooms to the Gulf spill. This is because he sees human partnership with fungi as essential to the broader project of creating a sustainable society. Like most other environmentalists, Stamets believes our society is hurting the earth and that the consequences of this damage will be severe. But he differs from the others in his conviction that fungi are the key to repairing that damage, healing the planet and accepting decay as part of nature as well.
Part of the problem is that most people don’t know much about fungi, so Stamets is constantly working to educate them. He talks a lot about the mycelium, the underground network of hairlike cells that constitute the main bodies of mushroom-forming fungi (the mushrooms themselves are merely the reproductive organs). The mycelium is a little-known but fascinating form of life that colonizes the soil and partners with trees and other plants growing nearby. It gathers information about water, nutrients, and pests, and then takes a surprising range of actions. It can move water and nutrients from many meters away to moisten a rotting log or nurture a growing tree. It can remove toxins from water or zap dangerous bacteria that threaten a partner plant. Most trees cannot reach maturity without its assistance.
And, of course, the mycelium eats. Stamets calls fungi the “interface organisms between life and death” because they specialize in breaking indigestible substances down into smaller particles that other living things can use as nutrients. It is this ability to digest complex organic compounds that makes fungi so promising for cleaning up oil.
A Side of Diesel with those Wood Chips, Please
Stamets first tested the fungal appetite for oil in 1997, when he teamed up with researchers at the Pacific Northwest National Laboratory to provide fungi for several lab-based experiments. The team selected mycelial strains and set them loose on diesel-contaminated soil. At the end of eight weeks, they found that the fungi had removed 97 percent of polycyclic aromatic hydrocarbons (PAHs)—heavy chemicals within oil that other forms of remediation had consistently failed to break down.
The chance to study this process outside the lab came a year later, when the Washington State Department of Transportation partnered with Stamets and the Battelle Marine Science Laboratory to compare different cleanup methods at a maintenance yard contaminated with diesel fuel. Workers scooped piles of the toxic soil onto tarps, and each pile was inoculated, either with a form of oil-eating bacteria or with Stamets’ mix of oyster-mushroom mycelia and wood chips.There were also several control patches of soil.
Again, the results were encouraging. The bacterial patches, Stamets says, remained “dead, dark, and stinky.” Same with the control group. Meanwhile, his own patches were teeming with huge oyster mushrooms feasting happily on the diesel compounds. “Analyses showed that more than 95 percent of many of the PAHs … were destroyed,” Stamets wrote, “and the mushrooms were also free of any petroleum products.”
Because the contamination in the soil patches was very uneven, it was difficult to measure the precise concentration of contaminants both before and after remediation. However, researchers at the Department of Transportation eventually declared the fungi-cleansed soil pure enough to use for landscaping purposes along the highways of Washington. And in the years since, Stamets’s findings have been replicated by many other researchers, and further study has shown that various types of fungi are able to partially or fully detoxify oil and pesticides. Geoffrey Gadd of the University of Dundee, Scotland, even found that fungi can break down depleted uranium from anti-tank shells by allowing it to bond with phosphates to form a more stable mineral.
Since the Deepwater Horizon spill in April 2010, Stamets has been testing his oyster mushrooms for tolerance to salt water and sun in preparation for a gig off the coast of Texas or Louisiana. So far, he’s managed to isolate a strain that can tolerate the salinity of Puget Sound, which is only slightly less than that of the Gulf. And he’s found ways to float the mushrooms cheaply on hemp “mycobooms” filled with straw and mycelia from which the mushrooms can metabolize oil on the surface of the sea.
Stamets says this new research is “very cool and unlikely to have been discovered if it were not for this disaster.” He believes it will be used in the near future and has applied for a provisional patent to prevent oil companies from stealing the research. But he says he would be happy to share it for free with affected communities in the Gulf of Mexico.
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