Foreign Spore Germination: Science Daily

Science Daily has an interesting article on utilizing Rhizopus microsporus fungi to recycle portions of the waste created by ethanol production.

It is based from a study conducted by Iowa State University researchers...
So, you know, check it out.

Science Daily: Researchers Feed Pigs, Chickens High-Protein Fungus Grown on Ethanol Leftovers

Mycorrhiza Don't Like to Share With Endophytes.

­So I have talked several times about the wonders of Mycorrhizal relationships, but did you know that not all fungi growing on roots fit into this group? It’s true, and these colonizers, known as endophytes, run the full gambit of beneficial to pathogenic for their host. What is a plant to do? Well, a new study out in PLOS One suggests the best course of action is to hope for a true mycorrhizal symbiosis to help keep their neighbors in check.

Mycorriza Reduces Adverse Effects of Dark Septate Endophytes (DSE) on Growth of Conifers

The team of Vanessa Reininger and Thomas Sieber looked at the effects of colonization by Phialocephala fortinii and Acephala applanata, a couple of ascomycetes that like to room together under the acronym PAC, with and without the presence of a common mycorrhizal fungi named Laccaria bicolor.

Laccaria bicolor

The PAC combination is routinely isolated from root tips throughout the Northern Hemisphere. It is in fact the most common complex and thus the main component of the Dark Septate Endophytes, a group of fungi identifiably by their… you guessed it, darkly pigmented septates. While these colonizers can sometimes be beneficial to the host plant they can sometimes be pathogenic and harmful instead.

There have been several studies on endophytes interacting with plants, and several on mycorrhizal relationships, but this study seeks to complete the circle and find out the interplay these two groups have with each other. Since both are clear hosts of L. bicolor and PAC in nature, the scientists chose to study these interactions on the Douglas fir and Norway spruce.

To do this the research team incubated L. bicolor into growth tubes for five and a half weeks, and then planted sterile seeds into said tubes. After allowing the plants to grow for another three and a half weeks they inoculated their roots with one of four PAC strains. Each combination, as well as a completely fungus-free control, was then grown at both 19°c and 25°c. The trees were grown for five months after inoculation under these conditions and root segments were excised for analyses. Each sample was measured for plant biomass, root vs. shoot growth ration, and fungal biomass.

One major factor across all data points was the growth temperature. On all plants this significantly altered both plant growth and colonization rates of both mycorrhiza and endophytes. But this study was meant to focus on the relationship of mycorrhiza and endophyte so I will too.

PAC strains were able to more densely colonize on Douglas fir then they were on Norway spruce as well as at the lower 19°c temperature. Mycorrhized plants significantly decreased the growth of PAC in both plants. It is noted by the researchers however that we have to take into account that L. bicolor was allowed to colonize before the inoculation of PAC.

The biomass of trees was also increased in the presence of mycorrhyzation compared to PAC. The fungal-free controls performed or outperformed both of these though.

Lastly the plants colonized solely by PAC invested more into root growth than both the controls and those with a mycorrhizal relationship. This means mycorrhizal symbiosis allowed the plant to focus on shoot production instead of fighting for nutrients with its fungus.

The researchers demonstrated that mycorrhization by Laccaria bicolor handily kept the team of Phialocephala fortinii and Acephala applanata from getting out of control; letting both the Douglas fir and Norway spruce get on with its day to day routine. Since all of these fungi live in close relation to each other in the wild the team speculated that this same mechanism is in play.


Awesome researchers:

Vanessa Reininger, & Thomas N. Sieber (2012). Mycorrhiza Reduces Adverse Effects of Dark Septate Endophytes (DSE) on Growth of Conifers PLoS One DOI: 10.1371/journal.pone.0042865

Photo cred:
US Department of Energy via Wikimedia

Fungal Word Friday

Mycelium

A mycelium is the conglomerate mass of hyphae making up the non-fruiting portions of filamentous fungi.

Oyster mushroom (Pleurotus ostreatus) mycelium
growing on coffee grounds in a petri dish.

Photo cred:
Tobi Kellner via Wiki-Commons

Blasting Biofilms with Plasma Torches

Killing a fungus doesn't mean you are free from its infectious grasp. You see many pathogenic fungi (and bacteria) grow in what is referred to as a biofilm, and killing the fungus doesn't make the biofilm magically disappear. If you think for a second that is obvious; killing a person wouldn't make the body go away, if it did the boys from Pulp Fiction would never have called in The Wolf.

Anyway, the biofilm is the complex of organisms living together in a self created extracellular matrix. That matrix does a number of things; it supplies a structure for the colony, holds some of the nutrients from the surrounding environment, and it offers protection from things like host responses and microbial forces.

Obviously killing the pathogen itself is the number one goal, but without actual removal of the infector, the host is still open to inflammation and secondary infection. Biofilms of pathogens are involved in well over half of infections contracted by once in a hospital. The problem is that conventional cleaning and disinfecting procedures biofilms often remain. It is for this reason that a new study has attempted to see the potential effectiveness of Plasma Torches on biofilms... Ok, technically Low-Temperature Atmospheric Pressure Plasma, but come on this is a torch:

Biofilm blasting Plasma Torch, driven with 5 slm Ar and
0.05 slm O₂, impinging a polymer surface.

Plasma treatment has been shown to be effective in killing pathogens and has been extensively studied in sterilizing and cleaning biomedical materials. But what about its potential for combining these aspects into killing and removal of biofilms in one awesomely torch-tastic moment?

A new study by researchers out of Germany seeks to answer this question. The team basically grew Candida albicans biofilms on a flat surface and blasted the hell out of it with an Argon plasma jet, and then also with a combination jet of Argon and Oxygen. They then used microscopic imaging to detect whether or not there was any biofilm remaining.

Atmospheric Pressure Plasma: A High-Performance Tool for the Efficient Removal of Biofilms

C. albicans is a good model for this study because it is one of the most prevalent biofilm creating pathogens. It is known to colonize pretty much everything from dental materials to prostheses and is responsible for some majorly life threatening infections.  And it is also a fungus, so I get to talk about this study.

The team grew C. albicans on a Polystyrene wafer that was pre-treated to enable a uniform colony growth on its surface. They did this by growing the fungus in a broth and then transferring a sample onto the wafer. The samples were incubated for 7 days, with a medium change every twenty-four hours, and then wafers were washed with a saline solution to remove any left overs.

And now for the plasma treatment.  Since previous studies suggested that a small distance allowed for the greatest plasma etching, the scientists held a constant distance of 7mm between the nozzle and sample. They then proceeded to subject the C. albicans, along with its biofilm matrix, to 60, 120, 180 and 300s of Argon plasma jet. They used a control that was exposed to the gas without full on plasma ignition. They repeated this with the aforementioned mix of Argon with a hint of Oxygen.

At 300s the Argon plasma did its initial job, killing C. albicans, but it didn't quite have the up-and-at-em to completely remove the biofilm entirely. However, as you can see in the below picture, adding some good 'ol Oxygen to the Plasma made for a clean wafer. The major caveat is that a plasma jet treatment is localized; I mean it can only hit the pathogen directly in front of it.

So, while more testing is always a good thing, this study demonstrates the potential use of Non-thermal plasma in efficiently removing C. albicans biofilms from surfaces. This could open up new possible sterilization and bio-decontamination techniques. Plus maybe it is the first step down the road to get a Plasma globe into every laboratory like on old sci-fi shows.

Awesome Researchers:
Katja Fricke, Ina Koban, Helena Tresp, Lukasz Jablonowski, Karston Schroder, Axel Kramer, Klaus-Dieter Weltman, Thomas von Woedtke, & Thomas Kocher (2012). Atmospheric Pressure Plasma: A High-Performance Tool for the Efficient Removal of Biofilms PLoS One DOI: 10.1371/journal.pone.0042539

Additional Photo Cred(Plasma ball):
Blaise Frazier aka PiccoloNamek via WikiCommons

Myco-Orchid Mycorrhyzal Relations

I think it is safe to say everyone loves orchids. And if by some chance you don't then you are dead to me, go read something else.

Now for all of you wonderful people that matter, which is of course everyone because nobody could belong to that other group, orchids are some an extremely diverse family of flowers. They grow all around the world and make up to about 10 percent of all seed plants. There are over 20,000 species which includes not only your typically prized Orchid flower but also things like vanilla. And guess what. Without fungi they wouldn't exist.

Dactylorhiza incarnata

You see, orchids are one of those many, many plants that rely on a mycorrhizal relationship with fungi to get nutrients. In fact some studies suggest that the distribution and specificity fungi are in part responsible for the rarity of some orchids. Recent research on the mycorrhizal relationships of Caladenia demonstrate that this in combination with other environmental goings on had a great impact on plant rarity.

A study recently out in PLoS One takes a look at this special relationship in five species from the Dactylorhiza genus.

Variation in Mycorrhizal Associations with Tulasnelloid Fungi among Populations of Five Dactylorhiza Species

The teams findings set to determine what species of fungi, as well as whether that specificity affected the rarity of species at least in this genus. And they found that the sampled Dactylorhiza species were not that stingy with whom they hooked up with.

On the five flower species they found 10 different isolatable fungal species with an average of 3 per plant (some had 2 others had 5 or six). The isolated fungi all came from the genus Tulasnella, which is a common symbiont of terrestrial orchids including several different genera. Most of the isolated Tulasnella species were found on more than one orchid of this study, and some of them were widespread amongst the specimens.

What this shows is that in contrast to the studies suggesting specificity amongst mycorrhizal symbionts, at least in Dactylorhiza a wide host of fungi could be utilized to get the job done. And while this study tackled whether or not mycorrhizal specificity was a major factor in Dactylorhiza, future tests focusing on other environmental conditions could help see if it triggered a constricted association. According to the researchers, more studies could also help determine what the purpose of multiple fungal infections is. Do they work in different ways to help acquire nutrients for the plant, or are they maybe competitors within the root system?



Awesome researchers:
Hans Jacquemyn, Agnieszka Deja, Koen De hert, Bruno Cachapa Bailarote, & Bart Lievens (2012). Variation in Mycorrhizal Associations with Tulasnelloid Fungi among Populations of Five Dactylorhiza Species PLoS One DOI: 10.1371/journal.pone.0042212

Photo Cred:
Roepers at nl.wikipedia

Fungal Word Friday

Capsule:
A polysaccharide sheath that grows around the cell wall of some yeasts.

Cryptoccocus in lung, the capsule is stained red.

Photo cred:
CDC Public Health Image Library #962

I drew more fungi

 Here are the latest additions to my sketchbook. Each one has the genus name on the drawing but i added them as captions for legibility.

Amanita

Pleurotus

Sarcoscypha
 (I know I misspelled on the actual sketch)

Pilobolus

Hope you enjoyed them.