Mushrooms in Manure: A Guide to Coprophilous Fungi

The biodiversity of the fungal community means that mushrooms can grow in a variety of substrates — from wood chips to sawdust, mulch, and even poop. Though it might not seem like the most appealing material to thrive in, there are several mushroom species that thrive in the nutrient-dense environment of animal manure. Some of these dung-loving species are culinary delicacies served at gourmet restaurants, while others are psychedelic shrooms that can alter your mind.

Regardless, herbivore feces can host a wide array of dung fungi. These mushrooms hold ecological significance and play a vital role in the natural world. They form a crucial link in the nutrient cycle and support both plant and animal organisms in an intricate web of interdependence.

Which types of mushrooms grow in animal dung?

Mushrooms that grow in animal manure are referred to as coprophilous fungi. They have a significant role in our ecosystem as they feed on feces and convert them into organic matter that can be reabsorbed into the earth (1). As a result, they enrich the soil and contribute to its overall fertility.

You might be curious about how mushrooms end up growing in animal poop in the first place. The life cycle of most coprophilous species begins when herbivores consume the mushrooms along with the other plant material around them. However, some microbes like the bird’s nest fungi, diverse ascomycetes, and the zygomycete Pilobolus have evolved to discharge their spores on surrounding vegetation to then be consumed by animals. Despite their path of entry, during digestion, the resilient mushroom spores survive their journey through the animal’s digestive system and stomach acid because of their thick cell walls. This adaptation gives the spores a chance to survive against other microorganisms incapable of surviving such a journey through harsh digestive enzymes (2). During digestion, this wall is gradually broken down, prepping it for germination. Once the animal finally releases their droppings, the spores are left perfectly situated in nutrient-rich manure. With the right conditions and climate, the spores will develop into mushroom mycelium and, later, into the fruiting body. These mature mushrooms are eventually consumed by herbivores again, repeating the fungi’s natural cycle

Although coprophilous species grow in herbivore manure, it’s important to note that not all types of manure equally meet the growth requirements of these fungi. For instance, some mushroom species like Coprinus radiatus and Panaeolus campanulatus exclusively prefer the growing conditions of horse dung since it is more acidic and decomposes more quickly. On the other hand, cow manure has a more neutral pH and is more dense in nutrients. Plus, it is more decomposed than horse manure due to the cow’s complex digestive system. And while some coprophilous fungal species strictly adhere to a diet of feces. However, many fungi in the Sordaria and Podospora genera are also capable of growing on other decaying substrates (3).

While some of the most popular culinary mushrooms are grown in manure, most edible mushrooms do not grow in animal dung. In fact, most edible varieties are cultivated on a wood-based substrate, such as oyster mushrooms and shiitake. Still, animal dung best supports the growth of many magic mushrooms that contain psilocybin, as well as inedible or even poisonous species. Despite the unappealing conditions in which these mushrooms grow, they have developed an essential symbiotic relationship with the animals that provide their growing conditions and spread their spores. 

We’ve included a variety of dung-dwelling mushrooms that deserve some recognition for their ecological significance and resilient nature. 

Edible mushroom species

Almost every edible mushroom that grows in manure belongs in the Agaricus family, but not every Agaricus mushroom grows this way, and some can be quite poisonous. Nonetheless, some of the most popular mushrooms you’ll see in your recipes and favorite restaurants are a part of this fungi family. 

White button mushrooms (Agaricus bisporus)

Due to their mild taste and versatile nature, White Button mushrooms are often found in grocery stores and common culinary mushroom dishes. They are the world’s most cultivated mushroom. 

Cremini mushrooms

Creminis, also known as Baby Bellas, are White Button mushrooms in a more mature form. They are also widely found in stores and have a more complex and earthy flavor.

Portobello

Portobellos are the most mature version of Agaricus bisporus, with a large brown cap and deeper flavor. These mushrooms have a more hearty texture that works great as a meat replacement.

Horse mushroom (Agaricus arvensis)

Often found in pastures, horse mushrooms are large in both size and flavor. They have a rich and robust taste and pleasing texture. Since these mushrooms are wild, it is best to avoid eating them unless examined by an experienced mycologist or mushroom forager and cross-referenced to avoid poisonous look-alikes.

Psychedelic mushroom species

Some of the most common psychedelic mushroom varieties have a surprising preference for animal manure. The two most common are:

Psilocybe cubensis

Psilocybe cubensis is one of the most popular and well-known types of psychedelic mushrooms. The species grows in different strains with varying physical features and levels of the hallucinogenic compounds psilocybin and psilocin. Some varieties include the Golden Teacher and the Amazonian. Species within the genus prefer growing in cow dung.

Panaeolus spp.

Several species within the Panaeolus genus prefer to grow in animal manure and are known to produce psychoactive effects. Some of the more known varieties include the Banded Mottlegill (Panaeolus cinctulus) and the Blue Meenie (Panaeolus cyanescens).

Inedible/Poisonous mushroom species

Since we’ve explored the edible and psychedelic varieties, it’s also crucial to recognize those mushrooms which inhabit manure-based substrate but aren’t suitable for human consumption. These mushrooms may not end up on our dinner plates, but they still have ecological significance.

Conocybe spp.

Many different types of mushrooms within the Conocybe genus prefer to grow in manure, such as the White Fibercap (Concocybe Apala). They can often be found in large numbers where manure has been used to fertilize the soil. These mushrooms are considered inedible as they contain hazardous toxins. However, this mushroom is not nearly as toxic as its deadly cousin, Conocybe filaris.

Inocybe spp.

Many mushrooms in the Inocybe genus can be found growing in animal dung. Some examples include Inocybe geophylla and Inocybe aeruginascens. Several species of Inocybe contain toxic compounds that can lead to severe gastrointestinal complications and even death if ingested.

Growing mushrooms with manure

If you feel inspired to cultivate your own manure-based mushrooms after reading this article, ensure you do the proper research to find out which type of animal poop is preferred by the specific mushroom species you want to grow. Growing mushrooms in a manure blend that is already pasteurized will be the easiest, most time-efficient, reliable option.

However, if you’re more of a DIY enthusiast, you can purchase manure from a local garden store and pasteurize it yourself. To do this, you will need to place the manure in a sealed, airtight grow bag and sterilize it in a pressure cooker at 240°F for three to four hours. Avoid overcooking the manure, as this can destroy the beneficial nutrients in the substrate, which are essential for mushroom incubation.

No matter your method of growing coprophilous mushrooms, we commend you for not being scared off by the smelly substrate. Rest assured, any odors are substantially minimized after pasteurization.

And for those who would rather purchase their favorite Agaricus mushrooms from a local grocery store, don’t be alarmed now that you know how they’re grown! After a quick wash, these mushrooms, regardless of their humble beginnings, are perfectly safe and delicious to eat.

References

1. Peterson, Robyn, Jasmine Grinyer, and Helena Nevalainen. 2011. “Secretome of the Coprophilous Fungus Doratomyces Stemonitis C8, Isolated from Koala Feces.” Applied Environmental Microbiology 77 (11): 3793–3801. https://doi.org/10.1128/aem.00252-11.
2. Richardson, Mike. 2003. “Coprophilous Fungi.” Field Mycology 4 (2): 41–43. https://doi.org/10.1016/s1468-1641(10)60185-5.
3. Krug, John C., Gerald L. Benny, and Harold W. Keller. 2004. “COPROPHILOUS FUNGI.” Biodiversity of Fungi, 467–99. https://doi.org/10.1016/b978-012509551-8/50024-6.