Oyster Mushrooms: Nature’s Janitor
While medicinal mushrooms have been used in China and Japan for more than 3,000 years to boost immunity and fight diseases, only in the last decade has their benefits become recognized in the United States. A number of compounds in fungi have been found to stimulate the function of the immune system, inhibit tumor growth and boost intestinal health. Particularly, mushroom substances called terpenoids help kill bacteria and viruses and exert anti-inflammatory effects, while complex chain-like sugars called polysaccharides have been shown to exert anti-tumor and immune system stimulating properties.
Oyster caps, angel’s wing, tree mushrooms, summer oyster mushrooms, pleurotte and shimeji are the different names for oyster mushrooms. Pleurotus ostreatus is one of the easiest species to cultivate. The color of the cap is influenced by the growing condition and the variety. Young oyster mushroom caps look dark gray to steel blue color. As they age, it turns pale brown. Though the flesh is white in color, oyster mushroom caps may be white, pink, yellow, gray or dark brown in color. The latin name Pleurotus ostreatus means “sideways oyster”, referring to the oyster-like shape of the mushroom.
The oyster mushroom is a saprotroph, meaning it feeds on dead and decaying matter (mainly wood). They are found on hardwoods throughout the world in the spring and fall. The mycelia will kill and eat nematodes (small roundworms) and bacteria, making them one of the few carnivorous mushrooms.
Oyster mushrooms can be cooked or eaten raw. Although they go well in many dishes, the most common way to cook oyster mushrooms is a simple saute or stir fry. Brown them in olive oil with herbs and spices of your choice. Oyster mushrooms taste great as chicken or seafood dish accompaniments or even as additions to soups or sauces. They have a nutty, subtle flavor that goes well in soups, stews, and sauces. While cooking oyster mushrooms, it helps to sauté them with some unsalted butter and chopped onions in order to bring out the maximum amount of flavor.
Use caution if trying them for the first time. Some people are allergic to their spores while others may experience an upset stomach. Try a small amount first to see how your body reacts.
Mushrooms are low in carbohydrates, calories and sodium. They are cholesterol and fat free. They contain as much fiber as 1 medium tomato. Oyster mushrooms are rich in protein. Oyster mushrooms’ protein quality is nearly equal to animal derived protein. Low fat content is mostly of the good unsaturated kind. Also contained are vitamins B’s, vitamin C , plus minerals, especially iron. Vitamin B3 in oyster mushrooms is 5-10 times higher as compared to any other vegetable. Calcium, phosphorous ands iron content in oyster mushrooms is double the amount available in beef, pork and chicken meat. Oyster mushroom contains most of the mineral salts that is required by the human body. It also contains antioxidants.
Oyster mushrooms can be a nutritious daily diet for people of all ages. So far they seem to have the most promising effect on cholesterol levels and cancer. It has shown activity in the following areas: antitumor, immune response, anti-inflammatory, antiviral and antibiotic. Oysters naturally produce compounds called statins. Statin drugs reduce “bad cholesterol” (LDL) by stimulating receptors in the liver to clear the cholesterol from the body.
As for cancer, research shows a possible anti-tumor effect from polysaccharides in oysters. A polysaccharide is a complex carbohydrate made up of smaller sugar molecules. Specific polysaccharides, known as beta-D-glucans, are suspected to stimulate the immune system to fight cancer. The beta-D-glucan isolated from oyster mushrooms is called pleuran. Studies are ongoing into the effects of pleuran for cancer treatment.
For people with hypertension, obesity and diabetes, oyster mushroom can form part of diet for it is low in sodium, potassium, starch, fat and calorific value. For those who suffer from hyperacidity and constipation, the alkaline ash and high fiber content oyster mushroom is the favored food. Oyster mushroom with its antibiotic property has varied health benefits for all.
MYCOREMEDIATION: Mushrooms and Hairmats
In addition to helping the body, oyster mushrooms can help the environment as well. The most fascinating use of these mushrooms is their growing role in mycoremediation. Mycoremediation is the process of using mushrooms to decrease pollution levels. The essence of mycoremediation occurs underground. In their day-to-day life, mushrooms eat forest-floor plant matter, and while doing so they break down cellulose and lignin, which occur side by side in the cell walls of plants. This plant matter is composed of hydrogen and carbon, just like petroleum products, and for the oyster mushroom there is little difference on a microscopic level between eating wood and eating nasty, sticky bunker oil; it’s all just hydrogen and carbon. Once these atoms are isolated, the fungus reconfigures them into carbohydrates, familiar molecules which many of us either love or hate. Oyster mycelium will eat through wood, paper, coffee grounds, and even petroleum products.
Meanwhile, fruits pop up above ground, and, assuming no heavy metals are present in the soil, the mushrooms are free of toxins. In time, the mushrooms themselves will be eaten or decay, nature will reabsorb them into the food chain, and any oil in the soil will be gone.
Oyster mushrooms can consume some of the most toxic petroleum products available and turn them into tasty, photogenic morsels that go wonderfully in white wine cream sauces and Japanese stir-fries with not a carcinogens remaining. Mycoremediation has gained substantial press in the wake of the 2007 Cosco Busan oil spill in the San Francisco Bay, and many environmental activists believe that if it is pursued by biotechnology developers, mycoremediation could completely rewrite how to handle the aftermath of future spills.
Matter of Trust
Imagine oil spills and pollution someday being decreased by mushrooms. This is the subject of numerous studies in polluted areas. Mycologists have been speculating for years on the possibility of someday employing oyster mushrooms, Pleurotus ostreatus, in toxic-waste cleanup projects, and when the freighter Cosco Busan scraped the Bay Bridge and spilled 58,000 gallons of sludgy bunker fuel, mushroom biologists quickly mobilized. They cleaned oil from San Francisco’s beaches using an unorthodox, albeit totally organic method: human hair and mushrooms. They partnered with the San Francisco nonprofit Matter of Trust, secured a small plot of federal land in the Presidio near the Golden Gate Bridge and proceeded to spearhead a historic experiment of oil-hungry mushrooms that has attracted nationwide media scrutiny. Using mats made of hair, they are absorbing the droplets of oil that have washed ashore since a cargo ship rammed the base of a Bay Bridge. Scientists, who plan to run chemical analysis of the substrate beneath the mushrooms and the mushrooms themselves, expect to find few to no hydrocarbons or other trace elements common to petroleum products remaining.
“Nature has all the solutions. We just haven’t been paying attention,” says Matter of Trust executive director Lisa Gautier, who has been laboring tirelessly since the day of the spill, becoming somewhat of an authority on the arcane subjects of ship fuel and fungi in the process. “In nature, there really isn’t any waste. All materials get dealt with, and it’s just a matter of harnessing the technology. Hair, which naturally absorbs oil from air and water, acts as a perfect sponge. Once the mats are soaked with black gunk, oyster mushrooms will take over, growing on the mats and absorbing the oil. The mushrooms will absorb the oil within 12 weeks, Gautier said, turning the hair mats into nontoxic compost. You layer the oily hair mats with mushrooms and straw, turn it in six weeks, and by 12 weeks you have good soil.”
In addition to breaking down the organic bonds in oil, oyster mushrooms are also powerful absorbers of mercury. Their mycelium channels mercury from the ground up into the mushroom itself. Once the mushroom is picked and destroyed, the mercury is removed from the environment. Heavy metal pollution is a serious problem all over the world. What if someday we were able to remove toxic heavy metals like mercury from our soil and water by cultivating mushrooms?
Gautier, meanwhile, made plans to launch the mushroom growing experiment. She has long opposed the standard government-assisted protocols of dumping or incinerating waste oil, and has concurrently admired the work of famed Washington state author, biologist and entrepreneur Paul Stamets, who has experimented with oil and oyster mushrooms in the past.
Stamets happened to be in town at the time of the spill for the annual Green Festival in San Francisco, and Gautier contacted him three days after the spill, by which time she and her volunteers had secured several thousand pounds of Cosco Busan fuel. Gautier explained the situation, and the two agreed to partner up, along with Stamets’ cohort David Sumerlin and the Mycological Society of San Francisco’s Ken Litchfield. Stamets called home and ordered an immediate shipment of several hundred blocks of oyster mushroom mycelium, and so the stage was set for history. “Not only are these hair mats a green method of cleaning up oil, unlike the polypropylene sponges they usually use, but they actually work better,” Gautier says. “There’s no reason not to use them, and if they’d accepted those hair mats and used them in the beginning, they would have had all that oil cleaned up.
Is it possible? Can we fix the terrible damage we’ve done to the environment through mushrooms? Plenty seem to think so. If mycorestoration is the wave of the future, oyster mushrooms should be leading the way. But is it science fiction or destiny? Without question, mycelium is running wild just under our feet, and many believe that, if only harnessed and controlled, fungi could help remedy the earth’s many problems of environmental contamination. The alchemy of mushroom biology is at work, and the state-run Department of Toxic Substances Control is watching closely, tentatively interested in adopting mycoremediation technology into standard practice.
A global movement seems already to be underway. The spill in the Yellow Sea, which discharged a reported 2.7 million gallons of oil just off the coast of South Korea and devastated the local fishing and aquaculture industries, iwas being remedied by crews armed with Bay Area hair mats. Cleanup crews addressing the oil spill in the Black Sea, which poured a thousand tons of bunker fuel into the water, also secured hair mats from Matter of Trust and Smart Grow to better mop up the sludge. And in Ecuador, where a 2001 pipeline break on the Toachi River dumped 10,000 barrels of crude oil and left a messy legacy festering on the banks, American volunteers have revived the long-dormant cleanup effort with hair mats in hand and a fresh sense of hope. There are even stubborn remnants of the memorable 1989 Exxon Valdez oil spill, reported at 11 million gallons, in Alaska’s Prince William Sound that still need attention.
It is disappointing that the oil industry continues to operate without a viable plan to clean up their messes, whether it’s in a tiny seaport in Alaska or in a big place like San Francisco, South Korea, or the Gulf of Mexico. It is inexcusable, and it shows a total lack of disrespect for everyone else on the planet. However, people expect the oil industry to try and block such progress in systemic change. The standard polypropylene oil pads are, in fact, a profitable business product for those invested in petroleum; countless pads are produced annually to aid in cleaning up some 2,500 annual oil spills.
“These people are profiting from their own messes, and they have closed eyes and ears to any suggestion of [cleaning up the oil] in some new way.”
Amidst so much oil and interest in hair mats, is there enough human hair in the world to support this new technology? The answer is yes. In the United States alone, some 320,000 hair salons produce an average of a pound of hair every day, most of which currently goes to landfill. Change is in the air, and the vision shared by activists and mushroom fanatics seems to be materializing. The biotechnology of human hair and mushrooms is gaining support and could eventually replace antiquated, dirty methods of toxic-spill management.
“The oil-cleanup business is a hard revenue stream to break into, but there’s been such a positive response,” Gautier says. “I think this is really the kind of thing that the world can grab on to. We’re all familiar with hair, oil and fungus, and this is a cheap and effective and organic system. We’re proving that it works, and I think the San Francisco Bay Area, with all that’s going on now after the spill, is going to revolutionize oil-spill cleanup.”
The Mess That Keeps Spilling
Since then, we have had numerous other oil spills, most notably the one in the Gulf of Mexico, a catastrophe that has since been confirmed the worst oil spill in US history. And the damage is still not over. Far from it actually. The ecological damage has yet to be determined, as well as the total damage done to economies of the Gulf Coast. Furthermore, we may never get a true estimate of the health effects on humans living with petroleum contaminated soil, water and food. And that doesn’t even scratch the surface of what the overuse of chemical dispersants can do to humans and the environment.
Among all of the chaos and the PR stunts, it appears as though the message of the mushrooms has once again been buried too deep to be visible to the public eye. Perhaps mushrooms would have been a better alternative to the chemical dispersants. Especially if we’re taking shots in the dark with untested methods already, why not fund research for more eco-friendly solutions to eco-disasters? If mycoremediation can find acceptance among petroleum investors or their friends, it could save them untold dollars on cleanup and liability payouts. It would also be a step in the right direction to regain public trust in the industry, while simultaneously helping their bottom line. In this scenario, everybody wins. Healthier business, healthier environment, and healthier people.