Subject: Re: oyster mushrooms

From: [email-masked] (xyzzyx)
Date: 26 Jan 1996 05:42:41 GMT

In article <[email-masked]>, [email-masked] says...
>
> have a problem with some oyster mushrooms I'm trying to cultivate
>or at least I think.
>        I obtained some sawdust spawn and used it to innoculate some
>used coffee grounds.  I sterilized the grounds with an autoclave at
>my lab so I'm certain that when I added the spawn the coffee was
>sterile.  Since then ( a week ago ) a crop of fungi of various types
>have taken over the top of the coffee grounds.  One white and
>dispersed mycelia, the other more like bread mold - white and green.
>        The Questions:  1) Is this expected or did I do a messy job
>of innoculating the coffee?    2) Am I, rather the mushrooms,
>screwed or do they have a chance against/with other fungus?
>3) What do oyster mushroom mycelia look like outside of the pressed
>sawdust - are they different or do they grow in big white clumps
>like what I received?   4) like #2, can I take the fungus off to
>help the oyster mushrooms or are they better off alone, or should I
>give up?
>        Any help would be much appreciated.  Thanks
>Alkk
>My email is [email-masked]. I'm using someone elses account to post.
>
Couple of questions?

How sure are you that the grounds were sterile?  Depending on the depth of a 
bed of spawn, it can take hours in an autoclave to get near 100% kill.

How did you go about transferring the spawn aseptically?  Obviously, 
absolute sterile transfer needs to be carried out.

How good was the spawn?  Bad spawn makes bad cultures.

I'd have to say that it is very UNLIKELY that your culture can be saved.  I 
would advise starting over.

I grew Pleurotus sajor-caju a while back.  The basic process went like this: 
Sterilize rye grain, cool, inoculate with master spawn culture or plated spore 
culture (PDA or MEA worked well).  The spawn should be white and somewhat 
fibrous in appearance.

Pasteurize your substrate by repeated immersion into near boiling to boiling 
water, discarding water between immersions; or run live steam through the bed. 
 Substrates that have worked very well for me are straw (untreated), wood chip 
animal bedding, chopped corn cob animal bedding.  Conveniently, all are 
available at your local animal feed store for mere pennies per pound, so you 
can afford to experiment (if you can find a place to keep 50 pound sacks of 
the stuff).

Inoculate the spawn, just as soon as it has cooled to room temperature.  Cover 
or bag the culture and keep it in the dark until the substrate is completely 
colonized (should look like a giant mass of white styrofoam).

When fully colonized, open the bag and uncover to expose as much surface as 
possible.  put in a very humid place, where daily day/night cycles can occure 
(this one needs light cyling to fruit).

Pinheads should appear in a couple of days, followed by prolific fruiting.  
Enjoy.

When it looks like fruiting has ceased, immerse the block of mycelium in water 
overnight (hold it down with bricks).  Remove from the water and repeat the 
fruiting process.  I have obtained up to five fruitings from one block of 
mycelium.  This genus is a weed.

I've even fruited off of my agar plates (pushed the lid right off, amazing)

Have fun.

George