Category Archives: Fungi

Friday Fellow: Amphibian chytrid fungus

by Piter Kehoma Boll

Today I’m bringing you a species that is probably one of the most terrible ones to exist today, the amphibian chytrid fungus, Batrachochytrium dendrobatidis, also known simply as Bd.

batrachochytrium_dendrobatidis

Several sporangia of Batrachochytrium dendrobatidis (spherical structures) growing on a freshwater arthropod. Photo by AJ Cann.*

The amphibian chytrid fungus, as its name says, is a chytrid, a fungus of the division Chytridiomycota, which include microscopic species that usually feed by degrading chitin, keratin in other such materials. In the case of the amphibian chytrid fungus, it infects the skin of amphibians and feeds on it. It grows through the skin forming a network of rhizoids that originate spherical sporangia that contains spores.

The infection caused by the amphibian chytrid fungus is called chytridiomycosis. It causes a series of symptoms, including reddening of the skin, lethargy, convlusions, anorexia and excessive thickening and shedding of the skin. This thickening of the skin leads to problems in taking in nutrients, releasing toxins and even breathing, eventually leading to death.

chytridiomycosis

An individual of the species Atelopus limosus infected by the amphibian chytrid fungus. Photo by Brian Gratwicke.**

Since its discovery and naming in 1998, the amphibian chytrid fungus has devastated the populations of many amphibian species throughout the world. Some species, such as the golden toad and the Rabb’s fringe-limbed treefrog, were recently extinct by this terrible fungus. This whole drastic scenario is already considered one of the most severe examples of Holocene extinction. The reason for such a sudden increase in the infections is unknown, but it may be related to human impact on the environment.

We can only hope to find a way to reduce the spread of this nightmare to biodiversity.

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ResearchBlogging.org
References:

Fisher, M., Garner, T., & Walker, S. (2009). Global Emergence of Batrachochytrium dendrobatidis and Amphibian Chytridiomycosis in Space, Time, and Host Annual Review of Microbiology, 63 (1), 291-310 DOI: 10.1146/annurev.micro.091208.073435

Wikipedia. Batrachochytridium dendrobatidis. Available at <https://en.wikipedia.org/wiki/Batrachochytrium_dendrobatidis&gt;. Access on March 4, 2017.

Wikipedia. Chytridiomycosis. Available at <https://en.wikipedia.org/wiki/Chytridiomycosis&gt;. Access on March 4, 2017.

Wikipedia. Decline in amphibian populations. Available at <https://en.wikipedia.org/wiki/Decline_in_amphibian_populations&gt;. Access on March 4, 2017.

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Friday Fellow: Scarlet Elf Cup

por Piter Kehoma Boll

If you like to pay attention on mushrooms growing on the forest soil, you may have found this little fellow sometimes, especially if you live in the Northern Hemisphere. Scientifically known as Sarcoscypha coccinea, its common names include ruby elfcup, scarlet elf cup, scarlet elf cap, or simply scarlet cup.

The scarlet elf cup is an ascomycete, so it is more closely related to morels and truffles than to more famous gilled umbrella-shaped mushrooms. Its cup-shaped fruiting body has a bright red color on the inside and a white color on the outside. It can be found growing on decayed wood in forests of North America and Europe, although it has also been recorded in Australia and Chile.

sarcoscypha_coccinea

Beautiful scarlet elf cups growing on a a fallen log. Photo by geograph user ceridwen*

The fruiting bodies of the scarlet elf cup may vary depending on the environmental conditions. Usually those growing on buried wood in places protected from wind are the greatest, while those growing on wood above the ground and being exposed to wind are usually smaller. There is no agreement on whether the fruiting bodies are edible or not. Some authors consider it edible, while other do not recomend its ingestion. However, there are some records of people eating it, and it is also used as a medicine by Native American peoples, such as the Oneida people.

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References:

EOL. Encyclopedia of Life. Sarcoscypha coccinea. Available at < http://eol.org/pages/1009245/overview >. Access on March 1, 2017.

Wikipedia. Sarcoscypha coccinea. Available at <https://en.wikipedia.org/wiki/Sarcoscypha_coccinea >. Access on March 1, 2017.

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Friday Fellow: Black Bread Mold

by Piter Kehoma Boll

Today’s Friday Fellow lives in our houses and our gardens, among our food and our crops. And every time we notice it, we get upset, because it means that something we were supposed to eat is now spoiled. Its name is Rhizopus stolonifer, or black bread mold.

rhizopus_stolonifer

The black bread mold growing on a peach. Photo by University of Georgia Plant Pathology Archive.*

Having a worldwide distribution, the black bread mold is mainly saprotrophic, growing on decaying fruits and bread. During its reproductive phase, it can be noticed as a black and hairy mold, as in the photo above. Eventually, this species can also cause an infection in human face and oropharynx, but most commonly it can be a pathogen of many plant species, thus being of economic concern.

rhizopus_stolonifer2

A closer look at the sporangia of Rhizopus stolonifer. Photo by Stanislav Krejčík.*

The black bread mold is a fungus of the order Mucorales, known as pin molds because their sporangia (the structures that contain the asexual spores) remember a pin. These sporangia, which are black, are what one usually notice growing on decaying food. When the sporangia are mature, they release spores of two kinds that germinate and originate two kinds of hyphae (known as + and -) and when two hyphae of opposite type come into contact, they fuse and create a zygospore, which then grows to originate new sporangia.

Due to its importance as an economic pest, there are many studies trying to find ways to get rid of it and very few studies trying to understand the fascinating things that it hides. What a pity.

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ResearchBlogging.orgReferences:

EOL – Encyclopedia of Life: Rhizopus stolonifer. Available at <http://eol.org/pages/2944808/overview >. Access on January 14, 2107.

Hernández-Lauzardo, A., Bautista-Baños, S., Velázquez-del Valle, M., Méndez-Montealvo, M., Sánchez-Rivera, M., & Bello-Pérez, L. (2008). Antifungal effects of chitosan with different molecular weights on in vitro development of Rhizopus stolonifer (Ehrenb.:Fr.) Vuill Carbohydrate Polymers, 73 (4), 541-547 DOI: 10.1016/j.carbpol.2007.12.020

Wikipedia. Black bread mold. Available at <https://en.wikipedia.org/wiki/Black_bread_mold >. Access on January 14, 2017.

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Friday Fellow: Christmas Wreath Lichen

ResearchBlogging.orgby Piter Kehoma Boll

Celebrating Christmas (or whatever you call this time of the year), today’s Friday Fellow is another lichen. And the reason I chose it is because it is known as Christmas wreath lichen due to its red and green color.

Cryptothecia rubrocinta growing on Patagonula americana in Argentina. Photo by Wikimedia user Millifolium.*

Cryptothecia rubrocicnta growing on Patagonula americana in Argentina. Photo by Wikimedia user Millifolium.*

Scientifically known as Cryptothecia rubrocincta, the Christmas wreath lichen is found throughout the Americas, from the United States to Argentina, and usually grows on shady tree trunks. In mature specimens, three different color zones can be seen, a central grayish-green zone, an intermediate white zone, and an external red rim. The central zone is usually covered by red nodules which in some cases may hinder the visibility of the grayish-green color.

The red color is caused by a combination of a quinone, called cheidectonic acid, and beta-carotene, which together protect the organism from radiation and provides DNA repair.

Apparently, this lichen only reproduces asexually, thus not forming any sexual structures. For that reason, it was thought for some time that it could be a basidiomycete fungus, although most lichens are formed by ascomycete fungi. Nowadays, however, we know that it is actually an ascomycete. DNA extraction is difficult, though, because several microscopic fungi live inside the lichen, thus somewhat making it a very complex organism formed by several interconnected species.

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References:

Elfie Stocker-Wörgötter (2010). Stress and Developmental Strategies in Lichens Symbioses and Stress, 525-546 DOI: 10.1007/978-90-481-9449-0_27

Wikipedia. Cryptothecia rubrocincta. Available at <https://en.wikipedia.org/wiki/Cryptothecia_rubrocincta&gt;. Access on December 16, 2016.

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Friday Fellow: Witch’s Butter

ResearchBlogging.orgby Piter Kehoma Boll

Last week I introduced a cyanobacteria that reminds me of my childhood and that is commonly known as witch’s jelly or witch’s butter. But witch’s butter is also the common name of fungus, so I thought it would be interesting to introduce it today. Its scientific name is Tremella mesenterica.

tremella_mesenterica

Witch’s butter on dead wood. Photo by Jerzy Opiała.*

Also known as yellow brain, yellow trembler or golden jelly fungus, the witch’s butter is found in all continents and appears as a lobed and curly jelly material growing on dead wood and may be mistaken as a saprobic species, a wood decomposer, but that’s not true. The witch’s butter is actually a parasite of saprobic fungi of the genus Peniophora, such as the rosy crust Peniophora incarnata.

The witch’s butter is edible, but usually considered tasteless. Some preliminary results indicate that it may reduce blood glucose levels, therefore having the potential do be developed into a hypoglycemic agent for the treatment of diabetes mellitus.

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References:

Lo, H., Tsai, F., Wasser, S., Yang, J., & Huang, B. (2006). Effects of ingested fruiting bodies, submerged culture biomass, and acidic polysaccharide glucuronoxylomannan of Tremella mesenterica Retz.:Fr. on glycemic responses in normal and diabetic rats Life Sciences, 78 (17), 1957-1966 DOI: 10.1016/j.lfs.2005.08.033

Wikipedia. Tremella mesenterica. Available at <https://en.wikipedia.org/wiki/Tremella_mesenterica&gt;. Access on September 22, 2016.

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Friday Fellow: Flounder Glugea

by Piter Kehoma Boll

While looking for flatfish you may eventually find one with some grotesque growth on the body, like the one in the picture below:

glugea_stephani_xenoma

A xenoma caused by Glugea stephani on a flatfish Limanda limanda. Photo by Hans Hillewaert.*

This sort of tumor is called xenoma and, in flatfish, is caused by a microscopical and parasitic fungus named Glugea stephani, or the flounder glugea.

The flounder glugea is part of a group of fungi called Microsporidia that until recently were classified as protists. They are unicellular and parasite other organisms, especially crustaceans and fish.

Once inside a flatfish, the flounder glugea enters an intestinal cell and starts to develop. They induce the host cell to increase in size and may give rise to the xenomas, which are the most extreme stage in the development of the disease. The proliferating and active stage of the glugea are free in the cytoplasm of the host cell, but they may change into a spore-like form called sporoblast that remains inside a vacuole.

glugea_stephani

Image of electron microscopy of an intestinal cell of winter flounder (Pseudopleuronectes americanus) infected by flounder glugea (Glugea stephani). The S indicates sporoblasts inside the vacuole (SV) and the P the proliferating organisms inside the host cytoplasm (H). Image extracted from Takvorian & Cali (1983).

Fortunately most infections are mild and do not compromise the fish health, at least not very much…

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References:

Takvorian, P. M.; Cali, A. (1983). Appendages associated with Glugea stephani, a microscporidian found in flounder. Journal of Protozoology, 30(2): 251-256.

Wikipedia. Xenoma. Available at: < https://en.wikipedia.org/wiki/Xenoma >. Access on September 17, 2016.

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Friday Fellow: Rosy Crust

ResearchBlogging.orgby Piter Kehoma Boll

If you are walking through a forest in Europe you may find the bark of some trees covered by a thin rosy or orange crust. Commonly known as rosy crust, its scientific name is Peniophora incarnata.

peniophora_incarnata

Rosy crust growing on a dead branch. Photo by Jerzy Opioła.*

As with most fungi, the rosy crust is saprobic, i.e., it feeds on dead material, in this case dead wood, so that it is more commonly found attached to dead branches. It affects a variety of plant species, especially flowering plants, but may eventually grow on pine trees.

Sometimes considered a pest because of its ability to rotten wood, the rosy crust has also some interesting benefits. It has shown to have antimicrobial activity, being a potential source for the production of antibiotics, and is also able to degrade some carcinogenic products used to treat wood, such as polycyclic aromatic hydrocarbons.

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References:

EOL – Encyclopedia of Life. Peniophora Incarnata – Rosy Crust. Available at: <http://www.eol.org/pages/1009530/overview&gt;. Access on September 22, 2016.

Lee, H., Yun, S., Jang, S., Kim, G., & Kim, J. (2015). Bioremediation of Polycyclic Aromatic Hydrocarbons in Creosote-Contaminated Soil by Peniophora incarnata KUC8836 Bioremediation Journal, 19 (1), 1-8 DOI: 10.1080/10889868.2014.939136

Suay, I., Arenal, F,, Asensio, F. J., Basilio, A., Cabello, M. A., Díez, M. T., García, J. B., González del Val, A., Gorrochategui, J., Hernández, P., Peláez, F., & Vicente, M. F. (2000). Screening of basidiomycetes for antimicrobial activities Antonie van Leeuwenhoek, 78 (2), 129-140 DOI: 10.1023/A:1026552024021

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