Author: Thomas Roehl

#026: Pseudogymnoascus destructans 5

#026: Pseudogymnoascus destructans

The fungus Pseudogymnoascus destructans is the causal agent of White-Nose Syndrome (WNS) of bats. WNS is most destructive to bats during the winter.  Its primary effect on bats is to change their behavior during winter.  Bats with WNS are observed to wake up frequently, fly around during the day, and cluster near the entrances to their hibernacula during the time that they should be hibernating.  This extra activity kills bats in two ways.  For one, they could either freeze to death while flying around outside.  Alternatively, the extra activity could deplete their fat reserves and the bats could starve to death.

#025: Production of Soy Sauce 0

#025: Production of Soy Sauce

There are two ways to make soy sauce: the traditional brewing process or the modern chemical hydrolysis process. In short, the traditional process involves the fermentation of soybeans and wheat by fungi and some bacteria.  The hydrolysis process extracts the amino acids from soy and adds other ingredients to create a liquid similar to soy sauce.

#024: Fungi in the Production of Chocolate 1

#024: Fungi in the Production of Chocolate

Along with red roses and cheesy cards, chocolate is one of the common Valentine’s Day gifts. So on this day when heart-shaped boxes of chocolates are a common sight, I thought you might like to learn a little about how chocolate gets from the cocoa beans to the cloying boxes (be thankful I didn’t decide to discuss fungal diseases you can get from roses).  You probably already know that chocolate comes from the seeds of the cacao tree, Theobroma cacao.  The first way in which fungi allow for the production of chocolate is by helping the cacao tree to grow.  In order to get nutrients required for growth, all trees participate in mutualistic relationships with fungi called mycorrhizae.  There are a number of types of mycorrhizae, but Theobroma cacao only forms endomycorrhize.  In these mycorrhize, fungi in the phylum Glomeromycota penetrate the root cells of the tree and form specialized...

#023: Tremella fuciformis, the Snow Fungus 2

#023: Tremella fuciformis, the Snow Fungus

This beautiful jelly mushroom also goes by a variety of other common names, including: silver ear fungus, white ear fungus, and white jelly fungus. The fungus fruits from decaying wood and produces white, translucent mushrooms that have a gelatinous consistency.  Its name seems to come from its white color and roughly snowball-shaped fruiting bodies.  Although, if you ask me, its name was probably also inspired by its “graceful lobes,”* which look somewhat like large, squishy points on a snowflake.  The snow fungus’s range is tropical to subtropical, but it can apparently be found in the United States at least as far north as Indiana.   Despite its name, you will not find this mushroom poking out of snow-covered branches.  The mushroom prefers to fruit in the summer and fall, so if you want to see this fungus for yourself you’ll either have to wait half a year or visit the mushroom...

#022: Nematode-Trapping Fungi 1

#022: Nematode-Trapping Fungi

Fungi have developed a variety of ways to trap and kill nematodes. These include: adhesive branches, adhesive knobs, adhesive networks, non-constricting rings, and constricting rings.  None of these fungi use nematodes as a primary food source.  However, fungi sometimes need extra nutrients, especially nitrogen.  Forming traps is very energy-intensive, so they are only formed when nutrients are scarce and nematodes are present.  Fungi detect nematodes by “eavesdropping” on ascarosides, the chemicals that nematodes use to communicate with each other.  If you want to see these fungi in action and/or get a better understanding of nematophagous fungi, watch the YouTube video (in two parts) linked below*.  For your convenience, I have noted the time at which each type of trap is discussed in the video.

#021: Pleurotus ostreatus, The Oyster Mushroom [Archived] 6

#021: Pleurotus ostreatus, The Oyster Mushroom [Archived]

Note: This is an archived post. Read the current version of this post here. The oyster mushroom is one of the few species of mushroom that you can routinely find at a grocery store. This is due to the fact that it is saprobic (it degrades dead plant material) and is easy to cultivate across a range of substrates.  P. ostreatus will decompose pretty much anything with cellulose: from logs to sawdust to straw to toilet paper.  Oyster mushrooms are often sold in grow-at-home mushroom kits, usually with a substrate like sawdust.  In nature they are usually found on logs or standing dead trees.  Occasionally you will find them growing terrestrially from buried wood.  The Oyster prefers hardwoods, but can also be found on conifers.  The name “Oyster Mushroom” refers to their shape and color, rather than taste.  The fruiting bodies are semicircular to shell-shaped or fan-shaped, with a short or...

#020: Aleurodiscus oakesii, Smooth Patch Disease of Oak [Archived] 0

#020: Aleurodiscus oakesii, Smooth Patch Disease of Oak [Archived]

Note: This is an archived post.  You can read the current version of the post here. How to use a trees to identify a mushroom (without seeing the actual mushrooms): If you are more than a casual observer of trees you have probably learned that oak trees often have smooth patches in their normally rough bark.  What you may not know is that these smooth patches are caused by the fungus Aleurodiscus oakesii.  This fungus only feeds off of the tree’s bark, so it does not cause any damage to the tree.  However, it does result in patches of bark that are more smooth than usual.  These patches are known as “smooth patch disease.”  As the fungus is not harmful to the tree, the main impact of the disease is the undesirable cosmetic effect it has on trees in peoples’  The disease is common on oaks, especially on white oaks,...

#019: Apiosporina morbosa, Black Knot of Cherry [Archived] 0

#019: Apiosporina morbosa, Black Knot of Cherry [Archived]

Note: this is an archived post.  You can view the current version of this post here. And now for something completely different: identifying trees from a long way away. If you’ve ever tried to identify deciduous trees in the winter, you know how hard it is to identify a tree based on its bark.  However, thanks to the fungus Apiosporina morbosa, identifying cherry trees in winter becomes a walk in the park.  Apiosporina morbosa is an ascomycete that parasitizes cherry and plum trees.  Commonly known as “black knot,” the fungus forms black, dry, cracked, irregular swellings on branches which grow to surround the branch.  According to Michael Kuo, these knots look like “dried cat poop on a stick.”*  Although this is not the most attractive-looking fungus, it is very helpful for identifying cherry trees from hundreds of feet away, especially in winter when the knots are not hidden by leaves.

#018: Characteristics of the Phyla Blastocladiomycota and Neocallimastigomycota 1

#018: Characteristics of the Phyla Blastocladiomycota and Neocallimastigomycota

These two groups of fungi were recently taken out of the Chytridiomycota and elevated to the rank of phylum. Not surprisingly, both of these phyla produce motile spores (zoospores).  The blastocladiomycota inhabit fresh water and soil and fill similar ecological roles to the core chytrids.  Many of the blastocladiomycota are pathogens of small, aquatic animals (such as nematodes or water bears), algae, or semi-aquatic plants.  The genus Allomyces contains saprobic species often used in experiments.  In Allomyces the female gametes secrete the pheromone sirenin to attract the male gametes.  The main difference between the blastocladiomycota and the chytridiomycota is that the blastocladiomycota produce an extensive mycelium.  Furthermore, only certain cells at the tips of the hyphae produce sexual (male and female, haploid) or asexual (diploid) zoospores.  In the core chytrids, the entire thallus is used to produce zoospores.

#017: Characteristics of Phylum Microspora 1

#017: Characteristics of Phylum Microspora

Phylum microspora (not to be confused with the green algae genus Microspora) contains some of the most unusual fungi: the microsporidia. There are over 1200 described species in this phylum (and that is only a fraction of their biodiversity), divided into about 150 genera (plural of genus).  These organisms were originally thought to be protozoans, but recent DNA studies have demonstrated that they belong with the fungi.  The microsporidia are all obligate parasites of animals and have an extremely reduced cell structure.  They do not have mitochondria, so they can only grow and reproduce within the cells of their host.  Their very resistant spores persist in the environment for a long time and allow them to spread from one animal to another.  The spores are 1 to 40 micrometers long, making them the smallest eukaryotes.  The spores are rougly oval and have a cell wall made of chitin that is...