H2O2 in Agar Medium?

Joe Harrington joeharr at worldnet.att.net
Thu Feb 6 19:02:46 EST 1997

klh at ripco.com (Keith H.) wrote:
>I've heard accounts of cultivators using hydrogen peroxide as an additive in 
>agar medium to supress the growth of bacteria and mold.  Has anyone on this 
>newsgroup any experience with this sort of thing?  What proportions would one 
>use (assuming a 3% solution of H202)?  If it's effective against mold con-
>tamination, then why wouldn't the presence of H202 inhibit the growth of the 
>intended culture as well?  
>And, a few more questions:
>Wouldn't autoclaving the H202 destroy it? 

The peroxide is used at room temp, and if the proper substrate is 
selected, autoclaving, other than the agar media, is not required.

>Another mycophile suggested that the H202 might have unwanted mutagenic 
>effects.  Is this a real concern?    

I've not noticed any in the trials I've conducted so far. As the 
mycelium grows, it decomposes the peroxide. I should be having my 
first flush of Plerotus o. within the week.

>As a home-based amateur working out of a home-kitchen "laboratory," where 
>sterility is hard to maintain, I am interested in any possible means (short of 
>installing a laminar hood!) to reduce contamination.  I'd like to clone 
>store-bought exotics and experiment with growing them on a variety of 
>composted kitchen wastes.  Is H202 a feasible substrate additive as well?
>All opinions/information appreciated.

Dr. Wayne Rush wrote a very easy to read Hydrogen peroxide manual, 
geared toward the home grower. Thus far, I've had excellent results
with Zero contamination in my agar cultures, and no apparent retardation
in the growth rate. Peroxide can also be used as a very effective 
agent for pasteurization of different substrates. I paid $20 for the 
manual and it was well worth it to me and resolved a lot time problem
of contamination.  


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