Note: Descriptions are shown in the official language in which they were submitted.
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~U13STRAT~ FOR GR()WING 5HIITAK~3 MUSHlROOMS
TE ClHNICAL FIELD
The present invention is directed to ~ method of making a
composted substrate on which shiit~ke mushrooms, c~n be grown.
The invelltion is further dir~cted to a methocl o~ growing shiitake
mushroom3 which h ~uitable for commercial production.
BACKGROUND OF THE INVENTION
~ orest mushrooms, or shiitake (Lentinu~ edodes), have been
used both as food and medicine in Asia for hundred~ of years.
However, cultivation of shiitake h~s remalned in a primiti~,re state
until ~rery re~ently. Shiitake traditionally have been grown on tree
trunks, some types of trees supporting more abun~nt growth than
otherq. Growth of shiit~ke on trees typi~Qlly reguire~ between on~
and two years until the first crop of fruiting bodie~ is produced. ~
One method which has been ~ound to expedite the growth of
shiitake involves growing the mu~hrooms aseptically in plflstie bags
or in trsys on ~terilized ~ub~trAte. Such substrate~ generally
include ~aYv du~t, ~gasse, ~t~w~ paper chlps and the like, whi~h
are supplementedl with nutrients ~uch ~ ~tarch, yeast, sugars ~nd
protein. Il~ing this method, mushrooms ~an be harvested in as
little a~ three to four mont~ a~ter ino~ldation.
Un~ortunately9 thi~ aseptic ~rowth method is ill 3uited to the
establi~hed equipment and procedures employed by l~rge sc~le, com-
merci~l growers of white mushrooms (~). White mu3hrooms
~re grown on a pasteur1zed, composted substrate In tr~ys.
There~ore, there is a need ~or a method o~ growlng ~hlltnke mush-
rooms which is ~ompatlble lNlth the technlques snd flppAr~tus used
by the indu~try.
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The b~sic pro~edure for commerci&lly growing mushrooms
involves either bulk pasteurlzation o~ compo~t in highly inQulated
rooms ~alled "tunnels,n or pa~teuri~tion o~ compost fn tray3. Such
compost i~ then impregn~ted with rnushroom mycelia. This step is
referred to as ~pQWning~ arld is generally E~erformed in individuql
beds or tra~s to fRc11itQte h~ndling and to m~imize space utilizs-
tion. Altern~tively, the sp~wning ¢arl be performed in bulk,. The
spawn-impregnated compost is then allowed to develop under con-
trolled temperature and moi~ture conditions. When the compost is
sp~wned in bulk, the trays are ~illed after the sp~wn h~s perme-
~ted the compost. Orlce the hyphae of the mushrooms have per~
meated the compost9 condltions are ~ltered to csuse the mushrooms
to fruit. In the e~3e o~ white mushrooms, a thin layer o~ soil,
sand or pe~t i~ placed on top of the bed. The process o~
covering the bed is referred to AS "casingn. In the case of
~hitake, fruiting is stim~ted by significantly reducing the temper~-
~e of the mushroom beds. After the first crop of fruit l~s been
harvested~ ~dditional cy¢leg of ~ruiting occur, referred to ~s
"bre~ks'~ or "n~lshe37', until the nutrients in the compost have been
depleted.
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It is an object of an aspect of the invention to
provide a substrate for growing shiitake mushrooms.
It is an ob~ject of an aspect of the inven-tion to
provide a substrate for growing shiitake mushrooms
which is compatible with the apparatus and techniques
used by commercial mushroom growers.
It is an object of an aspect of the invention to
provide a substrate for growing shiitake mushrooms
which allows a first harvest within two to four months
of spawning.
It is an object of an aspect of the invention to
provide a method for growing mushrooms which eliminates
the need for aseptic growth conditions.
SUMMARY OF THE INVENTION
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759~i6
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A non-sterile, p~steurized, nutri0nt ~ub~trate ~omposi-
tion 3uit~ble for growing shiitake mushrooms consisting essenti~lly
of a mixture of a vegetative w~ste ~nd a mirer~l fertilizer, which
~omposition h~s been sequentially composted first at ambient and
then at mesothermic temperature~.
A process i~or pr~p~ring a nutrient substrate composi-
tion suitable for growth of shiihke mushrooms comprising
prep~ring a ~ompost mixture cos~isting essentislly of a
veget~tive wa~te, a misleraI rertilizer and ~ater, said mixture
haviog ~ moisture content of AboUt 65 to 80%;
~erobically digesting the mixture at ~mbient tempera-
tures for between sbout 1 and 9 days;
p~steurizing the mixture; and
further digesting the mi~ture st a mesothern~ic tem-
per~ture oi between about 45 to 55C for between about 3 to S
da~s.
A method for growing shiit~ke mushrooms on the non-
sterile, pasteurized, nutrient substrate o~ ~laim I comprising
mixing shiitake spawn with said nutrient sub~tr~te;
maintaining said spa~qn ~nd substrate mixture ~der
conditions which cause shiit~ke myeelia to permeate the spawn and
substrate mixt~e; and
causing the shiitake to ~ruit by maintaining the
shiitake mycell~ under a suitable temperature ~nd light regime.
A non-sterile, p~steurized, nutrient ~ubstrate ~mposi-
tion suitable for growlng shiit~ke mushrooms cc~ngisting essentially
o~ on ~ d~y weight basi~ a mixture o~ ~7-50% wheat straw,
24-47% corn cobs, 8-20% cotten3eed meal, 2-6~6 gypsum, 0-3%
potash and O.S-3% Am monium ~trate~
~2~5~
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DETArLED DESCRIPTION
A compost formul~tion h&~ been ~ound which supports the
growth of ~hiitake mushrooms and i3 prepared osing techniques Rkin
to those commercially used to prep&re compost ror growing white
mushrooms. The eompost COllSiSt~ es~enffRlly of ~erobially degraded
fnrm or ~orest (vegetative) wa~te materiaI~, supplemented with min-
eral fertilizers. It is important that the Qddition oi~ animal wasge
materisls, such as poultry manure and cow m nure, be avoided.
Although not completely understood, it is believed th~t heavy
metals, such 8S zin~ and msnganese) or organi~ amides present in
such Qnimal waste materials inhibit shiitake development. Composts
prepQred using the combination Or vegetatîve waste material, animal
w&ste material end miner~l sources have pre~riously been used as a
substrate for growing other genera of mæhrooms.
The vegetative waste material used to prepare the compost
generally consistg of cellulosic and ligni~containing material3. Such
materi~ls include cottonseed meal, pe~nut meal, rape seed meal,
corn ~ nd ~ereal grain straws such as wheat, o~t and rice,
snd the like. In a preferred embodimerlt of the invention, the
compost ~rmldstion contairls A mixture of Yegetative wastes com-
prising corn cob, cereal straw and cotltonseed meal.
The mineral ~ertilizer component typically contains sources of
calcium, nitrogen ~nd potassium. The term fertilizer, used herein,
refers to a cheml~l mixture which~ ia combination ~ith the vege-
tative waste, i3 capable Or ~u~taining mushroom growth. Any
~ources of c~lcium, nitrogen snd potassium known in the art m~y
be used, either organic or inorganic, with the exclusion of manures.
A preferred compo~ition o~ the minersl fertilizer component
includes ~ mixture of gypsum, ~mmonium nitrate ~nd potAsh.
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A broad r~nge OI component ratios c~n be wed when pr~
paring ~ compost for growing shiit~ke. The ~egetative w~ste com-
ponent comprises the bulk of the compost mixture. ~ a prererred
formul~tion9 whe~t straw is a m~or component, comprising ~rom
about 37-50% of the compost mixture on ~ dry weight ~sls; eorn
cobs can comprise frorn about 24~796 by weight; cottonseed me~l
~an comprise from about 8-20% by ~e3ght. Miner31 fertili3ers will
typically comprise from ~bout 3% to about 12% by weight of the
compost mixture. For e~Qmple, in ~ preferred rorm~ation gypsum
is added to the eompost mixture ~t between about 2 and 6% by
weight; potash is ~dded at about ~3% by weight; ~nd annmonium
nitrate i3 added at ~bout 0.5-3% by weight.
Other suitable vegetative waste m~terhls and miner~l ferti-
lizers mny be identified asld substituted Yor those noted ~bove on
the basis o~ routine testing. Unle~s otherwise indicflted, all per-
centages reported throllghout the speciîication ~nd claims are by
weight.
The vegetati~e waste materi~l alld the mineral fertilizers are
blend~d together to form a compost mixture which is chopped,
wetted ~nd assembled into p~les for aerobic digestion. The mixture
of the veget~tive wastes ~nd minernl ~ertilizers i3 wetted to a
moisture content o~ between about 6~ ~nd 80%. Prefer~bly, the
moisture- content is between 72 and 76% o~ the compogt mixture~
The compost mixture is the-l aerob}c~lly digested by
endogenou3 mlcroorganism~, th~t is microorganisms such as ~sc$eri~,
typically ~ and fw~gi ~hich are n~turally on the ~e~e-
tative msteri~l. The mixture cRn be Iormed into piles which flre
mech~nicfllly mixed periodically (about every two to three dRys~ to
insure suitable conditions for aerobic di~estion OI the vegetntive
wa~tes. Such nerobJc dlgestion (composting) contlnue~ ~or between
~bout one and nine d~ys. When ~erobic digestlon OI the eompost
mixture is c~rried out for longer than ~bout one weelc, the result-
lng yield OI mu3hrooms grown on that compost is reduced.
Thereîore, It Is preferred to allow aerobic digestlon for between
AboUt 4 and 7 d~ys.
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After digestion, the compost mixture 3s p~steurized ~t a
temperat~e of Qbout 60C to about 6SC for between about four to
six hours. It i3 important, how~ver, thQt the mixture not be steri-
lized. Pa~teurization c~n be nocomplished economic~lly by use of
live ste~m in an insul~ted space such as a compost tunnel. Thi~
step is ~im~d at eliminating organism3 in the compo3t which would
compete with the growing rnushrooms ~or nutri2nts.
The compost mixture can then be p~lrti~lly cocled to anintermediate temperature, between the pasteuri~ation temperature
and ambient tempePature. This temperature ~ondition, hereln
termed mesothermio9 is generally between about ~5 ~nd 55C,
preferably between ~bout 4g~ and 54 ~C. Keeping the compo~t ~t
such mesothermic conditions for between 2bout three to five days
allows for iurther degradation o~ the compost by endogenous,
thermophilic org~nisms into usable nutrientc. If the compost is
previougly sterili~ed such rurther degr~d~tion ~qould not be possible
in a reason~ble time.
The cornpo~t cRn then be further cooled to ambient tempera-
ture, generally between QboUt 18~ ~d 30C. Pre~erably, the tem-
perature will be ~bout 23 to a7c. A~ these ambient temperA
tures, shiitake mushroom spawn can b~ mixed into th~ compost
~; without l~rm. ~rain spawn conaisting of myeelia and their growth
substrute of rge, wheat~ bQrley or: the like, is pre~erred as u form
- Or mushroom sp~wn. The spawn is ~dded to t~e compost ~t a~out
B to 15% by dr~ weigS~t.
- Ths tr~y~ can be i~illed be~ore or arter mixing of the sp~wn
`~ with the compost. Ii~ desired~ the spswn can be Allowsd to grow
in bulk until the compost become~ thoroughly myceluim-impregnated
be~ore the tr~y3 are filled. The spawn and compost can be
pres3ed into tray~, ~nd covered wlth a moi~ture barrier, ~uch ~s
plastic Pilm or ~hee~; or gl~s~ plllte. The moi~ture ~rri~r is gen-
erally ramo~/ed when ~ruiting begins, and the beds kept molst by
~pplIcstion oP A Illi~t 0~ water.
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Using the described methodologies, a ~ ;t h~rYe~t of shJitake
mu~hrooms c~n be obt~ined within ~bout two to ow~ month~. Sub-
sequent breaks can be har~rested every tell to fourteen d~ys9
approximately. Such a cycle will prev~il ror about eight to ten
months, until the nutrient value o~ the ~ubstral:e ~s been depleted.
Applicant has found that the combination o~ the compost
formulation and the sequenti~l composffng procedure described ~boYe
is ideally sl1ited for producing ~ cosnpost ~uit~ble ror growing
shiit~ke mu3hrooms. Quite unexpectedly, shiit~ke call be grown in
high yield on the compost, whi~h is not steriliæed.
No light is required during $he sp~wn-run~ However, under
cropping condiffon3, light is introduced. As recognized in the prior
Art~ nouresc~nt tubes delivering between ~bout 300 and 659 lux are
sufficient~ As i9 also well known in the art, rruiting of the mush-
rooms can be stimul~ted by ~ubject~ng the mycelia to a "~old
shoek9' tPeatm0nt. Under croppirlg conditions the air temperature is
preferably lowe~ed to promote ~ruiting, to ~bout la to 20C while
the compost temper~turs i~ about 16 to ~5C.
An important feature o~ the present invention is th~t the
direct addition OI high gr~de or refined food sour~es such QS
starch, yeast, sugar and protein to the sub~trate is not required.
Instead, th0 present invention reliæ upon the in ~itu production o~
such ingredients by endogenous microorganisms in the presen~e of
the vegetative w~ste and mineral i~ertilizer m3~ture. Une2~peetedly,
the prs~ence in the compost of endogenous thermophiles which
survi~e the pa~teurization treatment, provide ~urther digestion of
the sub~trate, and remain in the compo~t during spawning, do not
adversely inhibit shiitake ~velopment and growth.
The compost o~ the present invention and the method ~or its
preparal:ion are pArtlcularly well ~ulted to growing ~hiitake mush-
rooms com mercially or on a large ~c~lle. Su~h oompost c~n be
prepared and handled erficiently wing ~guipment alrendy us~d
industrlally ror grol~ving ~ or white mushrooms.
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The ~ollowing working exRmple~ are not intended to limit the
scope of the Invent~on, but merely to exempliîy concretely the
methods to be employed and result3 which c~n be expected when
the present invention i5 used.
The following components were Qdded together in the listed
proportions9 mixed and thoroughly wetted to about 75% moisture
content to prepare the compo~t o~ the present invention.
%~
Wheat ~trsw 38.1
Corn cobs 46. 6
Cot ton~eed m~al 8. S
~r~non i um n i t r a t e 1 . 4
Pota~h 1. 4
Gypsum 4. 0
To f~cilitate ~erobic digestion, the pile wa~ turned ~nd
ricked 2-3 times during the period Or 7 to 9 d~ys prior to
pa~teuriz~tion. LiYe steam was used to r~ise the ~ir temperature
to 60-65C for ~6 hours and thereby pQSteUrize the compost. The
air temperst~e w~s ~lowly reduced to between 49 and 54C for 3
to 5 day~ to permit further dlgestlon of the compost by
endogenou~ thermophile~ The compo~t w~ thel~ cooled ~urther to
24C o~er 2 to 3 day~, ~t ~rhich time it was ready for spawning.
rlous ~ 3t~in~ o~ shiitake mu~hroom3~ ~ll oi~ which Qre
ava~l~blQ rrom the Department of Pl~nt Pethology, Pennsylvania
State ~iYe~ity, were ~osYn on the ¢ompost prepared flccording to
E~ample L.
I~ushrooms were h~rvested o~rer ~ period of 8 months a~t~r
~pawning and weighed. Conver~ion e~iciencie~ are expressed as
Wet wel~t of mushroom~
oa
The ti me required to a~hieve fir~t harvest from spa~vning wa~ also
determined. The re~t~ Are ~ummarized below.
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~hl it~ke Days to Yield ~ rsl
~tr~in _t ~X~rve~t ~m2) E~ _ cy ~)
~C-379 111 7. 7 45
WC-325 107 3. 1 18
~ 31~ lg~ 0.2
wc-3ns 160 0. 9
While the present invention h~s been described with respect
to preferred embodiment~9 it should be und~rstood thflt Y~lriOUS
chflnges m~y be m~de without de~arting ~rorn the ~pirit ~nd scope
o~ the invention 619 pQrltic~arly cl~imed below.
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