Fungal Word Friday: Disjunctor cell

First, I apologize that this is on Saturday and not Friday as it should be, I dropped the ball, much as I have been doing of recent weeks on my more in depth pieces. I will find a way to get back on task.

A Disjunctor cell is a cell that breaks open, or undergoes lysis of some form in order to release a conidium.

Coccidioides immitis showing a disjunctor cell on the right.

Photo cred: http://www.studydroid.com/imageCards/03/ef/card-3620318-front.jpg

Fungal Word Friday: Cystidium

Cystidium is a large cell generally seen between clusters of basidia of a basidiomycete. They have a variety of morphological characteristics that can be used to help with species identification. 

Cystidium stained with Congo red

There are several classifications of cystida based on where they grow on the mushroom (on the edge of the lamella, on the face of the lamella, on the margin or surface of the cap, or along the stipe.)
 In addition they can be classified by structure; do they contain a refreactive yellow body (Chrysocystidia), or do they have a granular or oily appearance (Gleocystidia.)

Photo Cred: Peter G Werner (Own image) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Fungal Word Friday: Hydrophobin

Fungi live all over the place... duh. The thing is, those fungi need to be able to withstand a wide range of environments and pressures in order to do so. On of their tools for survival is a group of proteins called hydrophobins.

Hydrophobin Water Resistant Monolayer assemble!

Hydrophobins are less then 100 amino acids long and rich in cysteine. What makes them special is that only filamentous fungi produce them and they have the ability to self assemble into a monolayer along  hydrophobic:hydrophilic barriers, such as water and air.
Basically hydrophobins give filamentous fungi a barrier to help moderate its interaction with the environment, allowing them to grow in all sorts of habitats.


Photo cred:  Lijealso [Public domain or Public domain], via Wikimedia Commons

Mushroom of the Month: Common Split Gill

For Christmas I received the National Audubon Society Field Guide to North American Mushrooms. In addition to that, I went out walking on Christmas Eve and found a mushroom. Taking those two things into consideration, I had no other option than to use the key from the Christmas gift I received to identify the mushroom I found over my Christmas holiday for the first Mushroom of the Month in 2013.

I found this fuzzy little thing in South East Kansas on  December 24, 2012.

White to Cream or Yellow Spore Key

1. Gills and or flesh exuding white, colored or clear

fluid (latex) when cut; gills attached; veils absent; on

the ground--Lactarius pp. 680-697

1. Gills, etc., not exuding latex when cut--2

2. Gills brittle, typically flaking when flicked with

finger; cap often some shade of red or purple; gills

attached; veils absent; on the ground--Russula pp. 697707

2. Gills not as above--3

3. A ring of tissue present on stalk or cuplike tissue

about stalk base or both--see Key A.

3. Not as above--4

4. Stalk off-center to lateral or absent; on wood or

wood debris--see Key B

Key B

(Stalk Off-Center to Lateral or Absent)

1. Mushrooms tough to leathery or woody--2

1. Mushrooms fleshy to firm-- 10

2. Mushrooms tough--3

2. Mushrooms leathery to woody -- 7

7. Mushroom fanlike; "gills" irregular, fleshy--8

7. Mushroom shelflike; "gills" regular, leathery--9

8. Cap white-hairy; "gills" split lengthwise--

Schizophyllum commune

And there we have it, the mushroom of the month is Schizophyllum commune,also known as the Common Split Gill. Which is thought to be the most widespread mushroom in the world, growing on every continent except Antarctica. 

Zygosaccharomyces bailii wants to ruin your Snakejuice

We are upon the hour of a new year, which of course means booze! Now, we all know that there will be a medley of alcohols consumed tonight. I am sure that we are also all fully aware that we owe thanks to yeasts, for making that fermentation process so readily available.

 

But not all yeasts want to help with your intoxication. And in the same way they will spoil your good times, those yeasts are called spoilage yeasts.

One of the widest spread spoilage yeasts, Zygosaccharomyces bailii, is so successful because it has the ability to tolerate a wide range of stressful living conditions (like fermented products.) While many products like wine, mayonnaise, and even pickles, are generally described to be shelf stable; Z. bailii is ready to get all up in there and have a good time. One of the sweet skills that lead this yeast to be successful is that it can metabolize both glucose, and acetic acid (which is generally seen as a stressor/killer of yeasts.)

Zygosaccharomyces bailii wants to ruin your Snakejuice

 A new study published in the December 28 issue of PLOS One seeks to explore the relationship of Z. bailii’s utilization of these substrates and how it manages to grow efficiently when both are present. Does it utilize both in the same metabolic pathways? Or do the two get consumed separate and independent of one another?

The Fate of Acetic Acid during Glucose Co-Metabolism by the Spoilage Yeast Zygosaccharomyces bailii

In order to determine whether Z. bailii grew more efficiently in the presence of just one substrate or the other, the team grew strains in isolated substrates as well as mixed substrates of Acetic Acid and glucose. Throughout the growth cycle they measured the biomass and compared amongst the cultures. The results of this demonstrated a number of things.

When comparing those growth rates  and biomass produced on the isolated substrates to those on the mixed substrate cultures, the team found that a mixed growth medium held a lower growth rate at a pH of 3.0 over either pure substrate. This suggests that with the pH lowered the acetic acid affects efficiency, which is evidence of a need by the cell, to overcome intracellular acidification. This is reinforced by the observation that when grown at a higher pH of 5.0 the decrease isn't evident. A similar difference in growth rate is noticed in the purely acetic acid substrate cultures. However; when grown on a mixed substrate of Glucose and acetic acid, Zygosacharomyces bailii utilizes both the acid and sugar simultaneously. The yeast appears to use each of the substrates individually as both a carbon source and an energy source, showing no effect in the presence of the other. This is significant, because generally speaking the presence of glucose reduces the usage of substandard (energy wise) carbon and energy sources.

By using magnetic resonance spectroscopy and measuring 14C at various pathway steps, the researchers were able to determine that even when glucose is present, acetic acid will act as an additional source of acetyl-CoA during the Krebs Cycle, as well as for lipid biosynthesis. Basically that means Z. Bailii takes a typical environmental stressor and uses it to make extra amounts of the precursors for fueling one of the major energy cycles. And thus, your drink and New Year's Eve Bash are destroyed.

Awesome Researchers:
Rodrigues, F., Sousa, M., Ludovico, P., Santos, H., Côrte-Real, M., & Leão, C. (2012). The Fate of Acetic Acid during Glucose Co-Metabolism by the Spoilage Yeast Zygosaccharomyces bailii PLoS ONE, 7 (12) DOI: 10.1371/journal.pone.0052402

Photo Cred:
DTDT (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Gif - Ron Swanson of Parks and Recreation via GIFSoup

Fungal Word Friday: Pileipellis

 

The skin of a mushroom is called the cuticle.

 

 Russula mustelina with portion of cuticle peeled
away from the cap.

However; there are more specific names for the skin at a microscopic level in accord to what portion of the fruiting body they are located. Pileipellis is the name attributed to the microscopic level of the cuticle on the mushroom cap.


Image of Psilocybe aztecorum pileipellis (Microscopic make up of the cap cuticle.)

Photo Creds: 

Amadej Trnkoczy (amadej) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Alan Rockefeller [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Fungal Word Friday: Coprophilous

Coprophilous is a term used to denote that a fungus grows on dung.

Many fungi that grow on dung must find ways to launch their spores far enough away that they have the potential to be picked up by animals that would not eat near dung. The most famous of these fungi are those in the Pilobolus genera, which launch their spores with the fastest acceleration in the living world.

Pilobolus sp. growing on some poo.

Photo Cred: By 19Adelheid (Own work) [Public domain], via Wikimedia Commons