GROWING GOURMET - Anto2ni.it

MIND AND METHODS FOR MUSHROOM CULTIVATION 85
sue culture technique is also a philosophy of
behavior, ever-adjusting to ever-changing circumstances.
Much like a martial art, the
cultivator develops keen senses to constantly
evaluate threats to the integrity of the sterile
laboratory. These enemies to sterile culture are
largely invisible and are embodied within the
term "contaminant".
A contaminant is anything you don't want to
grow. Classically, Penicillium molds are contaminants
to mushroom culture. However, if you are
growing Shiitake mushrooms, and a near-by fruiting
of Oyster mushrooms generates spores that
come into the laboratory, then the Oyster spores
would be considered the "contaminant". So the
definition of a contaminant is a functional one—
it being any organism you don't want to culture.
The laboratory environment is a sanctuary,
a precious space, to be protected from the turmoils
of the outside world. Maintaining the
cleanliness of a laboratory is less work than
having to deal with the aftermath wreaked by
contamination. Hence, contaminants, as soon
as they appear, should be immediately isolated
and carefully removed so neighboring media
and cultures are not likewise infected.
Overview of Techniques for
Cultivating Mushrooms
The stages for cultivating mushrooms parallel
the development of the mushroom life cycle.
The mass of mycelium is exponentially expanded
millions of times until mushrooms can
be harvested. Depending upon the methodology,
as few as two petri dishes of mushroom
mycelium can result in 500,000-1,000,000 lbs.
of mushrooms in as short as 12 weeks! If any
contaminants exist in the early stages of the
spawn production process, they will likewise be
expanded in enormous quantities. Hence, the
utmost care must be taken, especially at the
early stages of spawn production. Several
tracks lead to successfully growing mushrooms.
For indoor, high-intensity cultivation,
three basic steps are required for the cultivation
of mushrooms on straw (or similar material)
and four for the cultivation of mushrooms on
supplemented sawdust. Within each step, several
generations of transfers occur, with each
resulting in five-to hundred-fold increases in
mycelial mass.
I. Culturing Mycelium on NutrifiedAgar
Media: Mushroom mycelium is first grown on
sterilized, nutrified agar media in petri dishes
and/or in test tubes. Once pure and grown out,
cultures are transferred using the standard cutwedge
technique. Each culture incubating in
100 x 15mm. petri dish can inoculate 10 quarts
(liters) of grain spawn. (See Figure 63) If the
mycelium is chopped in a high-speed stirrer and
diluted, one petri dish culture can effectively
inoculate 40-100 quarts (liters) of sterilized
grain. These techniques are fully described in
the ensuing pages.
II. Producing Grain Spawn: The cultures
in the petri dishes can be expanded by inoculating
sterilized grain housed in bottles,jars, or
bags. Once grown out, each jar can inoculate 10
(range: 5-20) times its original mass for a total
of three generations of expansions. Grain
spawn can be used to inoculate pasteurized
straw (or similar material) or sterilized sawdust.
Grain spawn is inoculated into sawdust, straw,
etc. at a rate between 3-15% (wet mass of spawn
to dry mass of substrate).
III. Producing Sawdust Spawn: Sawdust
spawn is inoculated with grain spawn. Sawdust
spawn is best used to inoculate a "fruiting substrate",
typically logs or supplemented sawdust
formulas. One 5 lb. bag of sawdust spawn can
effectively inoculate 5-20 times its mass, with
a recommended rate of 10:1 Sawdust-to-saw-
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