Note from Justine: This guest post by Shelli Nauman provides a wonderful introduction to the world of fungi.
My initial love of fungi came from their intrigue and mystery: they aren’t plants, and they aren’t animals. They are a type of microorganism and are often overlooked. I first learned of the Morel mushroom, sometimes called “Kansas caviar.” My father introduced me to these and other mushrooms — so, I have him to thank when it comes to my fascination with them. We would argue about who would get to eat most of the morels (you never waste morels) during their season. A cherished memory in my family is when my sister ate an entire platter of them without sharing with my mom and me, even though my father explicitly told her to share with us. Remembering this story brings laughs every morel season. In case you couldn’t tell, morels are a highly sought after fungi. Some go for 100 dollars a pound in the United States.
As I got older, I wondered why do they call it mushroom hunting? Mushrooms don’t move, so are you actually hunting them? How do you know where to look? How long have mushrooms been around? What’s their purpose? Why don’t they have an entire section of all kinds of mushrooms in the grocery store? How can they help our planet and us? None of these questions got any real attention from me until I started my path of microbiology in college. My love for fungi mushroomed when I took the course Biology of Fungi. I was hooked! Fungi are so fascinating — I was drawn to the colors, shapes, growing seasons, life cycles, ways they reproduce, healing powers, diseases they cause, diseases that make fungi sick, and, most of all, their taste! Fungi are my favorite and, to me, the most exciting of all microbes! (Bacteria are my second favorite.) Because of my love for fungi, I wanted to introduce you to them in this post.
In this introduction to fungi, you will learn the answers to the following questions:
- What are fungi?
- How long have they been on the planet?
- What are they used for?
- Where are they found?
What are fungi?
Fungi are eukaryotes, just like animals, protists (algae, amoebas, etc.), and plants. Eukaryotes are organisms that have a defined nucleus and other membrane-bound organelles. Animals, Plants, Protists, Bacteria, Archaea, and Fungi are the currently accepted kingdoms in Biology. Fungi can be single-celled or multicellular, meaning they can carry out functions either as a single cell or a group (multi) of cells.
When most people think of fungi, they immediately think of fruiting bodies (the part you see in the environment typically labeled as a toadstool or mushroom). In reality, fungi are everywhere. However, not all fungi produce a fruiting body that is visible to the naked eye.
About 2.2 – 3.8 million species of fungi in the world are known to mycologists (scientists who study fungi). But many fungi have yet to be discovered. Trying to think about how many different types exist is like trying to guess how many stars are in the night sky.
How long have they been on the planet?
Fungi have been around for a very long time. The oldest fungi fossil dates back to 1 billion years ago. Others have also been found that range from 715 – 810 million years old! It is thought that fungi brought vegetation from the ocean to land at the beginning of life on our planet.
Fungi hold the record for being the largest and possibly one of the oldest living organisms on planet Earth. Armillaria ostoyae, or the honey mushroom, was found in the United States, in Oregon. It covers approximately 4 square miles and is 2,000 – 8,000 years old.
What are they used for?
Fungi have been used for medicinal purposes for thousands of years by many different cultures. Only in recent history have they been gaining traction in Western society for their healing properties and not thought of as merely a food source. We have fungi to thank for many of our antibiotics. The first commercialized antibiotic, penicillin, came from a Penicillium spp. and is still widely used today. Most recently, the chemical psilocybin from “magic mushrooms” has been studied for its potential use in treating disorders such as depression, anxiety, and obsessive-compulsive disorders. We depend on fungi to produce a wide range of drugs, including but not limited to immunosuppressants, cholesterol medications, as well as anticancer and antiviral compounds.
Fungi also help make fermented foods. Because of fungi, we get to enjoy sourdough bread, kefir, kombucha, beer, wine, and miso, to name a few. Read more about fermented foods on the Joyful Microbe here. They also make food preservatives. For example, commercial citric acid is produced by Candida spp. of yeasts and the mold Aspergillus niger.
Fungi are used in bioremediation techniques, also called mycoremediation. They can break down and detoxify waste and pollutants such as heavy metals. Some fungi can “eat” plastic in landfills. Over the last two years, more than 50 fungi have been found that can degrade plastic! Imagine what else fungi can be used for…the possibilities are endless.
Fungi have a symbiotic relationship with many different organisms, but the most well-studied is with plants. Fungi provide nutrients, like phosphorus or nitrogen, from the soil for plants to use. Trees and many other plants use fungi to communicate with their neighbors through underground fungal “networks.” These networks are composed of fungal cells, which grow as long strands called hyphae. And the hyphae grow together and form a strand-like structure called mycelium. Think of it like our branching nervous system; they are long thin filaments that carry messages or even nutrients through the soil. Through this mycelial network, they chemically speak to one another and even warn each other of invaders like aphids.
Where are they found?
Fungi are found just about everywhere, especially in areas with nutrient-rich organic material and moisture available to them. Dead vegetation, like leaves or rotting tree limbs, provides a suitable home for many fungi. So, you can often find fungi right close to your house or at a nearby park. However, these aren’t the only places to find them but are your best bets on where to start looking when you go mushroom hunting. Fungi are excellent decomposers. But they are also life-givers. Everything alive dies eventually. It is inevitable. But imagine if every leaf that has ever blown off a tree was still around. We would have a massive pile of leaves by now if it weren’t for fungi. So, you can think of them as some of our best “recyclers” on Earth.
Fungi thrive in environments with temperatures ranging from 68° F to 86° F. However, some fungi grow well in colder temperatures. For example, think of the old piece of pizza in your fridge that is growing green or white mold. These fungi are a type of extremophile referred to as psychrophiles (cold-loving) because they prefer cooler temperatures.
Final fungal thoughts
We’ve learned a great deal so far about fungi, but, likely, we haven’t even begun to understand the fungal world and its role regarding life and the planet. What fungi have taught me is that everything on the Earth is connected. We are all needed — no matter what species you are, how big or small you are, or how old you are — we all have a purpose in this beautiful world. With more discovery and continued curiosity, we will better understand fungi, their symbiotic relationships, and all they do for us. I look forward to the next chapter in the ongoing story of fungi and can’t wait to find out what else they are capable of!
Shelli Nauman is an industry microbiologist in Lawrence, Kansas. In 2014, while at KSU, as an undergraduate, she won the Travel Fellowship Award for her fungal research involving the Burr Oak tree and presented at the Ecological Genomics Symposium. She also taught General Microbiology lab for a semester and enjoyed showing her peers their first glimpse into the microbial world. In October 2019, she was asked to be a guest speaker at Baker University, talking to upcoming and budding science majors about her educational and career path. She loves talking about microbes with anyone at any time. You can find her @microshelli on Instagram or Pinterest.
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