Agar media failing after inoculation ? :(

[Bromo_DragonFly]

Hi all,

 

Two days ago I made my first ever agar media in 4 petri dishes.
the recipe I chose to make was V8, which can be found here.

the media solidified very well.

 

The problem is, two days after inoculation with Agaricus bisporus spores, the following is happening :

1. a weak mycelium has started to grow around spores. (barely visible)
2. the media around the spores has melted !
3. a liquidish thing is made in that zones around spores and where the mycelium is visible.
4. the agar media has changed in shape at that zones (dent).

and these problems are in all 4 dishes I made.

I did the whole process sterile and clean.

 

Any Idea why this happened ? and how to avoid it next time ?

 

and sorry, the attached image can't show the watery thing accumulated in mycelium-grown zone.

[arc]

 

Isn't this normal?

 

http://en.wikipedia.org/wiki/Mycelium

 

It is through the mycelium that a fungus absorbs nutrients from its environment. It does this in a two-stage process. First, the hyphae secrete enzymes onto or into the food source, which break down biological polymers into smaller units such as monomers. These monomers are then absorbed into the mycelium by facilitated diffusion and active transport.

[Bromo_DragonFly]

I don't think it's normal,

because i have seen many photos from web/books and in none of them i could see a melted/damaged agar media

caused by the mycelium growth. and never heard of this watery thing being made by mycelium !

any idea about the reason ?

[arc]

Well, I am no expert in this. But there doesn't appear to be any other contamination. I think the liquid is simply the water left over after the nutrients have been taken. I think all four examples being at the same stage is a good sign. Time will tell.

[CharonY]

Agaricus should not be able to utilize agar (i.e. liquefy it). I wonder, does it grow on V8 medium at all? I was under the assumption that it does not prefer acidic conditions, but I could be wrong. I believe malt extract is more common.

 

Arc, just so you know, agar has been used as a polymerizing agent specifically because there are not so many microbes around that are able to hydrolyze it.

Edited February 9, 2014 by CharonY

[Bromo_DragonFly]

 

Agaricus should not be able to utilize agar (i.e. liquefy it)

Do you mean if mycelium is utilizing agar, the agar should be liquified ?!

have anyone ever encountered this liquidation problem with rowing mycelium ?

Edited February 10, 2014 by Bromo_DragonFly

[arc]

OK, I know less then nothing about this stuff but -

 

http://homeguides.sfgate.com/grow-agaricus-bisporus-24894.html

 

"Cover the colonized compost with a uniform 1 1/2- to 2-inch layer, called casing to make a mushroom-growing medium. Make your casing with pasteurized sphagnum moss peat and add enough garden lime to raise its pH to 7.5."

 

Looks like CharonY is correct about the acidity, and also the malt by the way.

[Ringer]

You could always try to adjust the pH or water % to a range where the contamination won't grow. My university has a huge problem with mold getting in everything so every set of plates I make I leave one or two uninoculated and wrap it with parafilm to see if the contamination was due to my screw up or it happened after inoculation.