There’s both myth and magic about mycology that plant pathologist Dr. Barry Pryor finds fascinating.
“One of the most dramatic impacts of fungi on plants comes from a specific group, a particular phylum that has its own trajectory in the tree of life,” says Pryor. “Some of the first records of fungi associated with plants come from fossilized endomycorrhizal fungi whose spores have been found in fossil records dating back 500 million years.”
Fungus and Plants With Root Systems
That symbiotic relationship between fungi and plants with root systems benefits both organisms. “Fungi interact with plants at almost all stages of growth—from seed germination to plant maturity to plant disease to a decay of dead plants that recycle nutrients available for the next generation of plants.”
Pryor’s interest in plants has led him down the path of spore science and he’s become somewhat of a mushroom guru. As a university professor, one of his more popular courses is Mushrooms, Molds, and Man.
“All mushrooms are fungi, but not all fungi produce mushrooms,” he clarifies. “Probably 90 per cent of fungi don’t produce mushrooms that are the fruiting bodies of some species—much like the apple is the fruiting body of a tree.”
From a consumer standpoint, according to the American Mushroom Institute, recent annual US mushroom sales posted a $1.2-billion value based on the consumer purchase of nearly 950 million pounds of the tasty morsels.
Mushrooms represent one of the fastest-growing specialty crops worldwide, a growth driven by increased demand for locally grown product as part of a healthy diet, says Pryor, the driving force behind the fledgling Arizona Mushroom Growers Association.
The Upward Trend of Mushroom Consumption
The American Mushroom Council estimates consumption at four pounds of product per person, per year. “Historically, since 1850, mushroom production has been concentrated in Pennsylvania, specifically Chester County, as producers of durable field mushrooms like the white button, crimini, and portabello grown in open beds,” says Pryor. “These mushrooms travel well and have a shelf life of three weeks or so, unlike specialty mushrooms like oysters, shiitakes, lion’s mane, and others that begin to degenerate within a week. So, there’s a demand for local production of specialty mushrooms grown in controlled environments.”
That’s where his association, in concert with researchers at the University of Arizona Controlled Environment Agriculture Center and the U of A MycoCats come into play. “There’s no incongruency growing mushrooms in the desert; all you have to do is control the environment. If Pennsylvania can grow mushrooms in the winter, we can grow them in the summer and year-round.”
Currently, the MycoCat organization is conducting industry research. It is seeking to find innovative methods of completing the cycle of sustainability by studying ways to grow fungi in substrate made of a variety of recycled agricultural and post-consumer waste products.
While straw or wheat is a traditional substrate for mushroom spores, mesquite bean pods and cotton seed have proven to be a successful growing medium, as have used, greasy, ground-up pizza boxes that provide an additional food source for the mushrooms.
“We take things that would normally go into a waste stream landfill—like food waste, landscape debris, old textiles—and extract value-added product. Mushroom-forming fungi breaks them down into a substrate that we use to extract an edible product from, then let the substrate continue on its trajectory through the recycling steam. It’s amazing what fungi can do,” says Pryor.
Take the pizza boxes that contain fats, oils, and residual meat and cheese residue. “They’re not suitable for adding directly to a compost pile because they would change the microbial community. But fungi break things down to a condition where they’re suitable to compost. In a sense, it’s sort of like pre-composting a product before it hits the actual compost pile.
Mushrooms: The Quintessential Decomposter
“Mushrooms are the quintessential decomposers of the planet, turning almost anything into a form that can be readily utilized by other systems,” says Pryor.
One of his research projects involves taking spent substrate to make compost teas to add to plants in hydroponic or greenhouse systems that will provide plant nutrition and increase plant health by stimulating the plants defense responses.
Another idea under study is taking used substrate and packing it into long tubes like the straw berm bumpers found on road cuts to contain erosion. Using that same process, the tubes packed with substrate are laid in front of areas where dirty water moves into watersheds. That water would then filter through the berms, which would bioremediate some of the wastewater pollutants like insecticides, pesticides, and petroleum products.
“We also use the spent substrate to feed insects, taking things insects wouldn’t normally eat and converting them into a fungus-degraded substrate combination that insects can now utilize. Then, we can use the insects for protein sources for animal feed or perhaps for human consumption.”
Pryor says the protein content issue is significant, as is the ability of these miniature pharmaceutical factories to provide micronutrients and vitamins. “They’re 40 per cent dry weight protein,” says Pryor. “They contain all nine essential amino acids, are high in B and D2 vitamins, and have a higher digestibility index.”
Fungus - The Final Frontier?
Calling mushrooms “the protein source we should send into space,” he notes: “We can grow protein in a lot of different sources, but mushrooms have an advantage because of their pharmaceutical properties—antioxidants, antitumor, anti-inflammatory—all the medicinal properties that make them superior. You can’t just discount that. If we’re going to send astronauts into space, millions and millions of miles away from home, and say, ‘Here’s your protein source,’ we’re going to have to have some value-added and mushrooms provide that.”
There are other advantages. “Animals in space are complex, less precise, less predictable, and take up a lot of room. With plants in a spaceship, you have to generate energy to create light for photosynthesis. But you don’t need that with mushrooms—just an LED bulb and you can create protein in a culture that has only one living thing in it.”
In another futuristic move, Pryor and colleagues are developing automated growing and harvesting systems to be fitted into interplanetary space vehicles. And it goes beyond even that.
“Once these modular food systems have been developed, they can be put anywhere—in deserts, in the middle of a prairie, on ocean islands, we can even put them underwater off the continental shelf—another example of where developments in the space program have spun off potential for all kinds of improvements for life across the planet. Lunar greenhouses with mushrooms can be put in Antarctica, on Mount Everest, or sunk down into the oceans because the continental shelf is an untapped resource.”