Method for vessel cultivation of Lentinus edodes

A method for the vessel cultivation of Lentinus edodes in which seed fungi of Lentinus edodes are inoculated into a culture medium in a cultivation vessel comprising mainly light-impermeable portions but including some localized light-permeable portions, taking out the culture medium from the vessel after hyphae have been sufficiently developed in the culture medium and subjecting the culture medium to a fruiting body-producing treatment.

BACKGROUND OF THE INVENTION 
Field of the Invention 
The present invention relates to a method for the vessel cultivation of 
Lentinus edodes in which Lentinus edodes is cultivated in a vessel such as 
a bottle or bag, the culture medium is taken out from the vessel after 
development of hyphae and fruiting bodies are produced from the 
mushroom-generating surface of the culture medium, excluding the bottom 
surface thereof, wherein the generating position and the total number of 
fruiting bodies can optionally be controlled. 
The applicants have previously invented and described a method in which 
fruiting bodies of Lentinus edodes are produced from the 
mushroom-generating surface of a culture medium promptly and with 
assurance of success (see the specification of Japanese Pat. application 
No. 83133/76, corresponding to U.S. Ser. No. 808,977, filed June 22, 
1977). It is a principal object of the present invention to improve this 
method in such a manner that the generating positions and the total number 
of fruiting bodies of Lentinus edodes can optionally be controlled by 
controlling the radiation applied to the mushroom-generating surface of 
the culture medium, whereby fruiting bodies having a high commercial value 
can be produced with assured success. 
In order to be commercially acceptable, the raw fruiting bodies of Lentinus 
edodes should have an umbrella or cap portion diameter of at least about 3 
cm, generally from 4 to 6 cm. In the vessel cultivation of Lentinus 
edodes, in order to grow and produce large quantities of fruiting bodies 
as rapidly as possible, optimum conditions for the growth of Lentinus 
edodes are employed, but under such optimum growing conditions, the number 
of fruiting bodies produced in one culture medium is increased. Since the 
total weight of fruiting bodies that can or should be produced in one 
culture medium naturally is limited, if the number of fruiting bodies is 
thus increased, the sizes of the respective fruiting bodies are inevitably 
decreased and the quantity of commercially acceptable fruiting bodies, 
namely, fruiting bodies having an umbrella portion diameter of at least 3 
cm, is reduced. As a procedure for overcoming this defect, there has been 
proposed a method in which the fruiting bodies are thinned out. However, 
this method requires much time and labor and is not satisfactory for 
practical commercial purposes. 
SUMMARY OF THE INVENTION 
We have developed a method for controlling the number of fruiting bodies. 
According to our invention, in the vessel cultivation of Lentinus edodes, 
the number of generated fruiting bodies of Lentinus edodes can be 
controlled by using a vessel which is light-impermeable as a whole but 
which includes localized areas of light-permeable portions (namely, a 
vessel comprising portions which block transmission of light rays and 
other portions which permit free transmission of light rays), so that the 
light rays are applied only on discrete, localized areas of the 
mushroom-generating surface of the culture medium. 
More specifically, in accordance with the present invention, there is 
provided a method for the vessel cultivation of Lentinus edodes comprising 
inoculating seed fungi of Lentinus edodes into a culture medium in a 
vessel, taking out the culture medium from the vessel after hyphae have 
been sufficiently developed in the culture medium and subjecting the 
culture medium to a fruiting body-producing treatment, said method being 
characterized in that a vessel comprising mainly light-impermeable 
portions, but including some localized light-permeable portions, is used 
as the cultivation vessel. 
The shape of the vessel that is used in the present invention is not 
particularly critical, provided that the culture medium containing 
developed hyphae can be taken out as a unit from the vessel. For example, 
a wide-mouthed bottle, a cup-like vessel, a bag, a cylindrical vessel or a 
square pillar-like vessel can be used. However, in all cases, the vessel 
should have a structure such that light rays can be applied to localized 
areas of the mushroom-generating surface of the culture medium when it is 
present in the vessel.

The present invention will now be described by reference to the 
accompanying drawing which pertains to an embodiment in which a 
wide-mouthed bottle is used as the cultivation vessel. The appearance of 
the wide-mouthed bottle is as shown in the drawing. The hatched portion 1 
of the vessel is light-impermeable, and the circular portions 2 are 
light-permeable. As is well-known in the art, light radiation is necessary 
for the growth of Lentinus edodes, especially during the period of the 
growth of hyphae. The present invention utilizes this fact in an unobvious 
way for the vessel cultivation of Lentinus edodes. Hyphae of Lentinus 
edodes are grown by using a wide-mouthed bottle as shown in the drawing, 
and after development of the hyphae, the culture medium is taken out, as a 
unit, from the wide-mouthed bottle. The bed of culture medium is then 
subjected to a fruiting body-producing treatment, for example, a low 
temperature treatment. Fruiting bodies grow only from the portions of the 
mushroom-generating surface to which light was applied during the 
hyphae-forming stage and no fruiting bodies grow from the other portions 
to which no light was applied. Since light radiation is indispensable for 
the growth of Lentinus edodes during the hyphae-growing period, even if 
the entire surface of the culture medium, after it is taken out from the 
vessel, is exposed to light radiation during the fruiting body-generating 
period, fruiting bodies are produced only from the portions to which light 
radiation was applied during the hyphae-growing period. 
According to the method of the present invention, there is achieved a 
direct control of the number of fruiting bodies that grow from the culture 
medium. This has been impossible according to the conventional techniques 
of the vessel cultivation of Lentinus edodes. By controlling the 
positions and the areas of the light-permeable portions of the vessel, 
which otherwise is light-impermeable as a whole, the number of generated 
fruiting bodies can be controlled. 
A wide-mouthed bottle which has heretofore been used for the vessel 
cultivation of Lentinus edodes is made of a light-permeable, 
heat-resistant, synthetic resin such as polypropylene or glass, and it is 
light-permeable as a whole. When such wide-mouthed bottle is used as an 
example of a vessel for use in the present invention, it is necessary to 
provide light-impermeable portions on the bottle. As the methods for 
forming such light-impermeable portions, there can be employed a method in 
which portions of the outer wall or the inner wall of the wide-mouthed 
bottle are made light-impermeable by printing or coating same with a 
light-impermeable ink or paint having preferably heat resistance, or a 
method in which a metal foil, a light-impermeable paper such as black 
paper, a clay, a light-impermeable plastic tape such as black tape or a 
light-impermeable plastic film such as black film is applied, coated or 
bonded to the above-mentioned portions of the wide-mouthed bottle, or a 
method in which a composite vessel formed by combining a light-impermeable 
bottle having a number of small open windows with a plastic bottle is 
employed, as well as various other methods. The surface portions of the 
vessel which are not rendered light-impermeable by one of the foregoing 
methods constitute light-permeable portions of the vessel. At any rate, 
the wide-mouthed bottle that is used in the present invention is 
light-impermeable as a whole but it includes discrete, localized, 
light-permeable portions. The method of preparing such a wide-mouthed 
bottle is not particularly critical. Bag-like and cylindrical vessels can 
be formed in similar fashion. 
The light-permeable portions 2 will now be described. The shape of the 
light-permeable portions is not critical but they may have a circular, 
triangular, square or other shape (a circular light-permeable portion is 
illustrated in the drawing). In the case of circular light-permeable 
portions, it is preferred that the diameter of each circle is from 5 to 10 
mm. If the diameter is too small, the effect of the light rays for 
effecting the growth of fruiting bodies is not sufficient, whereas if the 
diameter is too large, a plurality of fruiting bodies are produced from 
one light-permeable portion and the desired effect of controlling the 
total number of fruiting bodies produced cannot be attained. The number of 
light-permeable portions formed on one vessel is optional but it is 
preferred that this number be changed depending on the weight of the 
culture medium contained in the vessel and the average weight of the 
fruiting bodies to be produced. In general, the total weight of fruiting 
bodies generated from one culture medium is about 20% of the weight of the 
culture medium, on the average. The weight of raw fruiting bodies having a 
high commercial value is about 10 g apiece on the average. Accordingly if 
it is intended to produce such high quality fruiting bodies, the number of 
light-permeable portions can be calculated according to the following 
formula: 
EQU N=(w.times.0.2)/10 
wherein N is the number of light-permeable portions provided in the vessel 
and W denotes the weight (g) of the culture medium. 
The positions of the light-permeable portions are distributed substantially 
uniformly and equidistantly on the fruit body-producing surface so that 
the umbrella or cap portions of each two adjacent fruiting bodies do not 
impinge against each other in order that said umbrella portions of 
respective fruiting bodies do not become deformed by each other. 
The intensity of light radiation applied through the light-permeable 
portions onto the culture medium in which hyphae are growing can be the 
light intensity customarily used in the cultivation of Lentinus edodes. 
Hyphae grow even under an illumination as low as about 1 lux and also 
under an illumination of up to 1000 to 2000 luxes. Preferred illuminations 
are in the range of from 10 to 500 luxes. There is no substantial 
difference between illumination by artificial generated radiation 
(radiation emitted from an illuminating equipment) and solar radiation. 
With reference to the color of the radiation, when single wave length 
radiation is applied with the same energy, violet-to-blue radiation 
(having a wave length of about 400 m.mu. to about 450 m.mu.) is most 
effective for the production of fruiting bodies and it is said that 
green-to-red rays (having a wave length of about 500 m.mu. to about 650 
m.mu.) are less effective. However, since green-to-red rays do not 
positively inhibit generation or growth of fruiting bodies, natural or 
white light artificial radiation can be directly applied without removal 
of green-to-red rays. The intended effect of the present invention can be 
satisfactorily attained by the use of ordinary natural radiation (solar 
radiation) or white light artificial radiation. 
The materials used to make the culture medium are not particularly critical 
in the present invention, and the materials customarily used for the 
cultivation of Lentinus edodes can be used in the present invention. More 
specifically, there can be employed sawdusts of various woods, bagasse, 
rice hulls, old papers, paper lumps, rice bran, corn bran, wheat bran, and 
other various agricultural wastes and by-products. Further, porous 
polymeric substances or porous natural or synthetic aggregates (for 
example, light aggregates) impregnated with nutriments can also be used. 
When hyphae of Lentinus edodes are cultivated by using a vessel which is 
light-impermeable as a whole, but which includes localized 
light-impermeable portions, and the culture medium is taken out from such 
vessel after sufficient development of the hyphae and then is subjected to 
a fruiting body-producing treatment, fruiting bodies are produced from the 
portions to which radiation was applied during the hyphae-cultivating 
period. Accordingly, the number of produced fruiting bodies and the size 
of respective fruiting bodies can be controlled by adjusting the number 
and sizes of the light-permeable portions. 
Although it has long been known that radiation is necessary for generation 
and growth of Lentinus edodes, there has not been proposed the concept of 
directly controlling the number of produced fruiting bodies of Lentinus 
edodes in the vessel cultivation thereof by utilizing this known fact. 
Accordingly, the method of the present invention is a novel and unique 
method based on this hitherto unknown concept. 
As will be apparent from the foregoing detailed description, the gist of 
the present invention resides in that, the vessel cultivation of Lentinus 
edodes, there is used a cultivation vessel which is light-impermeable as a 
whole, but which includes localized light-permeable portions. The portions 
of the culture medium to which radiation is applied during the 
hyphae-cultivating period are controlled, whereby production of an 
excessive number of fruiting bodies is prevented and large fruiting bodies 
having a high commercial value are produced in increased quantities. 
Accordingly, the present invention makes significant contributions to the 
art of cultivation of Lentinus edodes. 
The present invention will now be described in detail by reference to the 
following Examples. 
EXAMPLE 1 
A culture medium was prepared by homogeneously mixing the following 
components: 
Oak Sawdust: 6.9 parts by weight 
Bagasse: 3.9 parts by weight 
Defatted rice bran: 2.2 parts by weight 
Water: 18.3 parts by weight 
Then, 600 g of the thus-prepared culture medium was placed in a 
wide-mouthed vessel having an inner capacity of 1000 ml and a mouth 
diameter of 11 cm. The outer surface portion of this wide-mouthed bottle 
was coated in advance with a carbon black-type heat-resistant black paint 
so that the bottle was light-impermeable as a whole but circular 
non-coated portions each having a diameter of 10 mm, were left at 12 
points on the side wall of the vessel so that they were distributed 
substantially uniformly and equidistantly as light-permeable portions. 
Four inoculating holes having a diameter of 12 mm were formed 
substantially equidistantly along the inner surface of the side wall of 
the bottle, and in order to prevent intrusion of other fungi such as 
air-borne fungi, an air-filtering plug was set in the bottle mouth, and 
sterilization with pressurized steam was carried out at a temperature of 
121.degree. C. under a pressure of 1.2 Kg/cm.sup.2 for 90 minutes. After 
cooling the contents of the vessel, seed fungi of Lentinus edodes were 
inoculated in the four inoculation holes and also on the top face of the 
culture medium. ( 
Hyphae were cultivated at a temperature of 25.degree. C. for 51 days under 
irradiation of white fluorescent lamp rays having an illuminance of about 
200 luxes (the actual illuminance of the radiation applied on the culture 
medium in the bottle through the light-permeable portions was about 160 
luxes). Then, the culture medium was taken out from the bottle and was 
subjected to a fruiting body-producing treatment at a temperature of 
15.degree. C. and a relative humidity of 85%. Rudiments of fruiting bodies 
were formed only on the light-permeated portions of the culture medium 
which had been exposed to the radiation during the cultivation of hyphae, 
and after 5 days, complete fruiting bodies of Lentinus edodes were formed 
in these light-permeated portions. One fruiting body was formed on each of 
the light-permeated portions which had been exposed to the radiation (12 
fruiting bodies as a whole). The total weight of all the fruiting bodies 
and the average weight of one fruiting body are shown in Table 1. 
For comparision, the cultivation was conducted in the same manner as 
described above except that there was used a conventional wide-mouthed 
bottle which was completely and entirely light-permeable and which had no 
light-impermeable portions. The results obtained are shown in Table 1. In 
this comparative run, the positions for the production of fruiting bodies 
were not fixed, and the number of produced fruiting bodies was large and 
the size of each fruiting body was relatively small. 
Each of (1) the run according to the present invention and (2) the 
comparative run were carried out using five samples of the culture media. 
In each of the culture media treated according to the present invention, 
the umbrella portion diameter of each fruiting body was 4 to 5 cm and each 
fruiting body had a weight of about 10 g. Thus, fruiting bodies having a 
high commercial value were obtained in the runs according to the present 
invention. However, in the comparative runs, the majority of the fruiting 
bodies were inferior in commercial value because the umbrella portion 
diameter was less than 3 cm and the average weight was less than 4 g. 
Table 1 
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Effect by Localized Irradiation in the Bottle Cultivation 
of Lentinus Edodes 
Culture Medium 
Produced Fruiting Bodies 
Average Weight (g) 
Sample No. 
Number 
Total Weight (g) 
of One Fruiting Body 
__________________________________________________________________________ 
Run according to present invention 
1 12 124 10.3 
2 12 116 9.7 
3 12 135 11.3 
4 12 142 11.8 
5 12 125 10.4 
Comparative Run 
1 32 118 3.7 
2 40 134 3.3 
3 33 126 3.8 
4 36 122 3.4 
5 35 131 3.7 
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EXAMPLE 2 
By using a culture medium having the composition set forth below, the 
cultivation of Lentinus edodes was carried out in the same manner as 
described in Example 1 except that the light-impermeable portion was 
formed by applying a black vinyl resin tape to the vessel: 
Lauan sawdust: 8.3 parts by weight 
Rice hulls: 3.6 parts by weight 
Corn bran: 2.4 parts by weight 
Water: 16.6 parts by weight 
Each light-permeable portion had a square shape of about 8 cm on each side, 
and radiation having an illuminance of about 100 luxes, which was emitted 
from a white fluorescent lamp, was applied (the actual illuminance on the 
culture medium was about 80 luxes). The results obtained are shown in 
Table 2. It will readily be understood that advantageous effects can be 
attained according to the present invention. 
Table 2 
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Effect by Localized Irradiation in the Bottle 
Cultivation of Lentinus Edodes 
Culture Medium 
Produced Fruiting Bodies 
Average Weight (g) 
Sample No. 
Number 
Total Weight (g) 
of One Fruiting Body 
__________________________________________________________________________ 
Run according to present invention 
1 12 129 10.8 
2 12 145 12.1 
3 12 136 11.3 
4 12 132 11.0 
5 12 140 11.7 
Comparative run 
1 48 139 2.9 
2 52 148 2.8 
3 44 126 2.9 
4 50 142 2.8 
5 45 133 3.0 
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EXAMPLE 3 
A culture medium was prepared from the following components: 
Lauan sawdust: 5.8 parts by weight 
Rice hulls: 4.2 parts by weight 
Potato starch grounds: 1.2 parts by weight 
Defatted rice bran: 2.4 parts by weight 
Water: 19.7 parts by weight 
A transparent bag composed of a polypropylene film having a thickness of 50 
.mu. and having such a shape that when it was expanded, it had a bottom 
face of 10 cm.times.10 cm and a depth of 20 cm, was filled with 800 g of 
the culture medium. The height of the culture medium in the bag was 10 cm 
and the volume thereof was 1000 ml. The bag thus filled with culture 
medium was placed into an aluminum case (having a thickness of 0.5 mm, a 
bottom face of 10 cm.times.10 cm and a height of 10 cm) which had been 
molded so that the bag filled with culture medium fitted tightly therein. 
Four circular holes each having a diameter of 10 mm were formed on each of 
the four sides of the aluminum case (16 holes in total) so that they were 
uniformly distributed as light-permeable portions. The cultivation of 
Lentinus edodes was carried out in the same manner as described in Example 
1. As a result, sixteen fruiting bodies, each having a weight of about 10 
g on the average, were obtained in one culture medium. The total amount of 
produced fruiting bodies was 150 to 170 g. When the entire surface of the 
culture medium was exposed to radiation without using the above-mentioned 
aluminum case, the total weight of produced fruiting bodies was 
substantially the same as in the above run according to the present 
invention, but the number of the produced fruiting bodies was larger and 
many of them had a weight of 2 to 4 g.