by Lauren Jackson
Following one billion challenging years of preparation, we thought that the Midtown Farmers Market would be the optimal venue to unveil (part of) the story of fungi. In fairness, it took us humans just one week to plan the event, but we were only able to do so because fungi had been helping to shape the world as we know it, including elements of human culture, for such a long time. If you were able to join us for our Market Science event, you may have heard some or all of the following fungal synopsis…
Imagine Earth one billion years ago: the oceans were teeming with microbial life, some of which had evolved to become multicellular; the atmosphere had very little, but slowly increasing levels of, oxygen; and the land masses were barren rock. It is thought that life on land took a dramatic turn as fungi – perhaps as part of lichen-like associations – began to colonize the land and slowly break down rocks. The activity of fungi allowed for some plants to escape their aquatic environments about 500 million years later, and the lives of plants and fungi have remained tightly intertwined since. Fungi have evolved to become the best friends and worst enemies of plants, and nearly everything in-between, over the last 500 million years. And in just the last 12,000 years or so, humans have found innovative ways to exploit fungi, and we are still learning new ways to harness their unique natural abilities.
Mycorrhizae (say it with me, my-co-rye-zay), which is Greek for ‘fungus roots,’ are fungi that directly interact with the roots of more than 80% of all plants. These fungi increase the surface area that roots can use to absorb water by ~35-100 times! Importantly, mycorrhizae release enzymes and organic acids that liberate soil nutrients such as phosphorus, and literally pump them into plant roots. The immune systems of plants get a boost from their fungal friends, and they get physical protection from some of the bad actors that may be lurking in the surrounding soil. In exchange for all of this help, plants ship photosynthates (i.e. sugars made from photosynthesis) directly to the fungi to make their lives a little easier. This type of association, where both organisms benefit, is known as a mutualism.
At the other end of the spectrum, fungal pathogens cause about 70% of plant diseases, which can range in severity from cosmetic damage to complete mortality. Fungi and fungal-like organisms have been partly to blame for devastating famines including the Irish potato famine of the 1840s and the Bengal famine of 1943. Interestingly, the English were mostly a coffee-drinking nation before the coffee rust disease wiped out their massive coffee plantations in Java and other islands of South Asia just before the turn of the 20th century. Ergot of rye, caused by Claviceps purpurea, was responsible for St. Anthony’s Fire, which is the same fungus that Albert Hofmann famously isolated LSD from in 1938. Trippy stuff, huh?
Fungi are also the great recyclers of Earth, doing the heavy lifting to turn dead debris back into soil. You may have seen evidence of this activity in the form of mushrooms or conks growing out of logs and stumps. When you see a mushroom or conk, note that this is just the “fruit” of that fungus, and that most of the fungus is inside of the log releasing enzymes to break down wood into smaller components that they can absorb for food. Ötzi the Iceman was found with two different conks: the tinder conk that he used to make fire; and the birch polypore that he may have used as medicine. Amazingly, some of the same enzymes that fungi use to degrade wood can also be used to clean up contaminants such as diesel fuel, pesticides, dyes, pharmaceutical compounds, explosives and more!
Finally, it wouldn’t be fair to talk about fungi at the farmers market without mentioning how we use them for food and beverages. In what may have been two of the most fortuitous mistakes in history, yeast fell into somebody’s dough and somebody else’s juice about 12,000 years ago, giving rise to leavened bread and wine/beer. We have other interesting ways to modify foods with fungi including fermenting soy beans for soy sauce, preserving salami, and changing the flavors of cheeses. Kids (and even some kids at heart) that visited our booth learned how we use a fungus to make blue cheese, and they used blue spores from the cheese to make a living art project!
Of course, the epitome of fungal cuisine comes in the form of mushrooms. Through trial and error, we have discovered that at least 60 different mushrooms, and probably many more, are edible; and although button mushrooms are delicious, we made sure to encourage everybody who visited us to try other mushrooms that can be purchased or harvested wildly around the Twin Cities. Never eat a mushroom that you find in the wild without absolute certainty that it is what you think it is. It is best to go mushroom hunting with people who are experienced. Have fun with your fungi and try a few of the mushrooms listed below in your next meal!
1) Oyster mushrooms; 2) King oyster mushrooms; 3) Shiitake; 4) Enoki; 5) Maitake or hen of the woods; 6) Morels; 7) Chanterelles; 8) Lobster mushrooms; 9) Giant puffballs; 10) Chicken of the woods; 11) Lion’s mane