JP5797077B2 - Mushroom cultivation method - Google Patents

Description

  The present invention relates to a method for cultivating mushrooms, and more particularly to an artificial method for cultivating mushrooms including a simple, quick and effective sterilization process.

  In recent years, fungus bed cultivation has been popular instead of raw wood cultivation because it can be stably supplied throughout the year. Bacteria bed cultivation is made by planting mushroom fungi such as shiitake mushrooms, beech shimeji mushrooms, eringi, etc. on a culture substrate that is mixed with wood chips, sawdust, corn cob, pulp, paper, etc. and nutrients such as rice bran and bran. It is carried out by filling the cultivation container and placing the cultivation container under conditions suitable for the spread of mycelia and the fruiting body in the house.

  Usually, various bacteria such as molds and bacteria adhere to the culture substrate. As shown in FIG. 8 (A), these miscellaneous bacteria easily propagate under the growth conditions of mushrooms, and hinder the growth of the planted mushroom bacteria. It is extremely important to sterilize the culture substrate in advance in order to suppress the propagation of various bacteria during the mushroom cultivation and to propagate the desired mushroom. For this sterilization treatment, as shown in Non-Patent Document 1, heating-type sterilization, irradiation-type sterilization, sterilization chemicals, sterilization gas, and the like are used.

  Heating sterilization requires a heating process in which high-temperature or normal-pressure high-temperature steam (for example, 100 ° C. to 125 ° C.) is treated for 30 minutes to 6 hours, and a cooling process for one day or more, and equipment costs and energy costs are high. A lot of labor work hours. In addition, heating has the disadvantages that the culture substrate may be altered and that it is not effective for heat-resistant bacteria.

  Irradiation sterilization uses ultraviolet rays or radiation. Patent Document 1 proposes cultivating mushrooms using a culture substrate treated with radiation. In Patent Literature 2, when water used for a mushroom cultivation base material is subjected to radiation treatment, mixed with sawdust or the like to prepare a culture base material, and when the cultivation container filled with this is heat sterilized, It is proposed to treat the mushroom cultivation container with radiation.

  Irradiation-type sterilization is expensive in equipment and requires attention such as measures against radiation leakage. Only the irradiated surface can be sterilized. In particular, when an aggregate of chips such as sawdust, which is a medium base material for the fungus bed, is inside the fungus bed with adhering bacteria, effective sterilization cannot be performed with an irradiation type sterilizer.

  As for the use of sterilizing gas, for example, Patent Document 3 discloses sterilization of a mushroom medium characterized by introducing an ozone-containing gas into a sterilizing pot after heat-sterilizing a cultivation container filled with a culture substrate in the sterilizing pot. A method is proposed.

  However, the sterilizing gas and the sterilizing chemical have disadvantages that the treatment takes a long time, is harmful to the human body, has a persistence, requires a secondary treatment, and may generate resistant bacteria.

JP-A 63-63312 JP 59-205910 JP-A-57-174086

Published by the Japan Patent Office-Standard technology collection "Mushroom cultivation method" http: // www. jpo. go. jp / shiryou / s_sonota / hyoujun_gijutsu / kinoko / mokuji. htm Electrostatic Handbook, Section 17.4.2 “Food Disinfection”

  Then, the subject of this invention is low in equipment cost and energy cost, and is providing the cultivation method of a mushroom including the process which can perform effective sterilization by simple work for a short time.

  As a result of intensive studies on the above problems, the present inventor has found that when a high-voltage discharge is applied to the culture substrate, the drawbacks of conventional heating-type sterilization and the like can be eliminated, and the present invention has been completed. That is, the present invention includes a step of sterilizing the culture substrate by applying a high voltage discharge of 20 kV to 120 kV to the culture substrate in the mushroom cultivation method (hereinafter sometimes referred to as an electrosterilization step). A method for cultivating the mushroom is provided.

  In the sterilization examples described in Non-Patent Document 2, there are no examples of use for mushroom cultivation, particularly sterilization examples of culture substrates. As a conventional technique for applying electrical stimulation to mushrooms, JP-A-63-98322 describes that growth of shiitake is promoted when electrical stimulation is applied to shiitake mushrooms. However, this document neither describes nor suggests that it is used for sterilization of a culture substrate by high voltage discharge.

  The high-voltage discharge is applied to the culture substrate by interposing the culture substrate between a high-voltage discharge electrode and a counter electrode, and applying a high voltage between the discharge electrode and the counter electrode. In this case, the high voltage discharge distance is preferably 3 to 20 mm per 10 kV. In the present specification, the “high voltage discharge distance” means a distance at which a high voltage discharge comes between the discharge electrode and the counter electrode, specifically, from the distance between the discharge electrode and the counter electrode. Is obtained by subtracting the thickness of the culture substrate of the conductor intervening.

  The application time of the high-pressure discharge is, for example, 10 seconds to 60 minutes.

  The said sterilization process is performed after filling the said culture | cultivation base material in a cultivation container, for example.

  The sterilization step is performed, for example, when the culture substrate is filled into a cultivation container.

  The high voltage discharge includes a high voltage generation unit 10 and a high voltage application unit 30, and the high voltage application unit includes a discharge side electrode 35 to which an output terminal of the high voltage generation unit is connected, and the discharge side electrode. 35, a high-voltage applying device including a ground-side electrode 36 opposed to the ground-side electrode 36 through a discharge gap, and an application-side electrode 38 that is electrically connected to the ground-side electrode 36, wherein the high-voltage applying unit 10 It can be carried out by the high voltage application device which is accommodated in the cylindrical body 31 and only the application side electrode 38 is exposed.

  The discharge side electrode 35 and the ground side electrode 36 are preferably spherical.

  The present invention also provides a method for treating a mushroom culture substrate, wherein the culture substrate is sterilized by applying a high voltage discharge of 20 kV to 120 kV to the culture substrate.

  In the method for cultivating mushrooms of the present invention, by applying a high voltage discharge of 20 kV to 120 kV to the culture substrate, discharge products such as OH radicals, ultraviolet rays, and shock waves are generated, and this discharge product serves as the culture substrate. Sterilize. Thereby, it is possible to sterilize not only the germs adhering to the surface of the culture substrate of the cultivation container but also the germs living in the deep part of the cultivation container. The present invention can be said to be a method suitable for cultivation of mushrooms that require sterilization of the fungal bed as a chip aggregate in that the entire culture substrate can be easily sterilized in a short time.

  The time required for electrosterilization depends on the shape and capacity of the cultivation container, but is usually 30 seconds to 60 minutes, and can be remarkably shortened as compared with conventional sterilization methods. As a result of improved workability, the mushroom cultivation method of the present invention contributes to an improvement in production.

  Unlike the conventional heating-type sterilization, the present invention performs sterilization at room temperature, so that the equipment cost for heating and cooling is unnecessary, and the energy cost is low. In addition, since no drug or gas is used, safety is high.

  According to the method of performing the sterilization step after filling the culture substrate into the cultivation container, for example, 1 or above which can be moved in the vertical and horizontal directions or the circumferential direction with a certain interval above the cultivation container placed in a large number in the vertical and horizontal directions Several discharge electrodes can be installed, which enables efficient electrosterilization.

  According to the method of performing the sterilization step when filling the culture substrate into the cultivation container, for example, in the fungus bed cultivation, the discharge electrode to the nozzle for injecting the culture substrate in the culture substrate culture bag or bottling step As a result, the number of processes can be greatly reduced.

  The high voltage generator can be easily downsized. By using this apparatus for the mushroom cultivation method of the present invention, the work space can be reduced, and sterilization can be performed without moving the target culture substrate.

It is the schematic which shows one embodiment of the disinfection process of the cultivation method of the mushroom of this invention. In this embodiment, electrosterilization is performed after filling the culture substrate into the cultivation container. The culture substrate floats from the discharge electrode and the counter electrode. Since the culture substrate is a conductor, the high voltage discharge distance is the distance between the discharge electrode and the culture substrate surface and the sum of the culture substrate surface and the counter electrode. A variation of the embodiment of FIG. 1, wherein the culture substrate is in conduction with a counter electrode voltage. The high-pressure discharge distance is the distance between the discharge electrode and the culture substrate surface. In another variation of the embodiment of FIG. 1, the culture substrate is in electrical communication with the discharge electrode. The high-pressure discharge distance is the distance between the counter electrode and the culture substrate surface. (1) Plate-like discharge electrode and plate-like counter electrode, (2) Spherical discharge electrode and plate-like counter electrode, and (3) Needle-like discharge electrode and needle-like counter electrode. It is a graph which shows the relationship between distance and a discharge start voltage. It is a modification of the embodiment of FIG. 2 and is a schematic view when a plurality of culture vessels are electrosterilized with one discharge electrode. It is the schematic which shows another one embodiment of the disinfection process of the cultivation method of the mushroom of this invention. In this embodiment, electrosterilization is performed when the culture substrate is filled into the cultivation container. The high voltage discharge distance is almost regarded as the distance from the discharge electrode to the counter electrode. The schematic of the high voltage application apparatus suitable for using for the cultivation method of the mushroom of this invention is shown. (A) is the photograph which inoculated the mushroom to the culture base material which is not sterilized in the comparative example 1, and observed the breeding state of the fungus bed, (B) is a photograph which mushroom was applied to the culture base material sterilized in Example 4. It is the photograph which inoculated and observed the breeding state of the fungus bed. In (A), miscellaneous germs breed on most of the fungal beds. On the other hand, in (B), the bactericidal effect equivalent to steam sterilization is recognized, and the mushroom hyphae are growing smoothly. It is a photograph which shows the propagation state of various bacteria of an agar medium after making various bacteria adhere to an agar medium and storing. A (control) is a control medium to which no high voltage is applied, and B (100 kV) is a medium to which a high voltage of 100 kV is applied by the treatment method of the present invention. (1) and (2) are the results of repeated tests under the same conditions. It can be seen that the growth of miscellaneous bacteria is suppressed in the medium to which a high voltage of 100 kV is applied.

  The mushroom cultivation method of the present invention is the same as the conventional mushroom cultivation method except for the sterilization step. The mushroom cultivation method of the present invention includes a step of sterilizing the culture substrate by applying a high voltage discharge of 20 kV to 120 kV to the culture substrate. In the method for cultivating mushrooms of the present invention, the conventional sterilization process can be completely replaced by an electrosterilization process, or can be partially replaced.

  FIG. 1 is a schematic view of an embodiment in which a culture substrate is filled in a cultivation container and then electrosterilized. First, in a commercially available culture container such as a bag or a bottle, water is added to chips, sawdust, rice bran, bran, etc. to adjust the water content to a certain level, and then the base material is filled and sealed. The culture container is generally composed of an electrical insulator, but the portion of the ventilation filter that allows only air and moisture to pass through without passing through spores of germs (size 3 to 100 μm) can be energized. The reason is that the discharge electrons are much smaller than the spores of various bacteria and can penetrate the ventilation filter. Instead of the energization path by the ventilation filter, a conductor such as a conductor film that conducts electricity between the inner surface and the outer surface of the culture bag or the culture bottle may be installed in the culture container.

  The culture substrate is interposed between a high-voltage discharge electrode and a counter electrode, and a high-frequency high voltage or a high-voltage pulse (for example, a pulse width of 10 ns to 500 μs, a repetition period of 1 to 50 Hz between the discharge electrode and the counter electrode. ) To generate a streamer discharge or a spark discharge that reaches the counter electrode from the discharge electrode. Discharge products (OH radicals, ultraviolet rays, shock waves, etc.) generated by these discharges kill germs when penetrating through the culture medium located between the discharge electrode and the counter electrode. The reason for the sterilization is not limited to the present invention, but it is presumed that the discharge product destroys the cell walls and intracellular DNA and RNA of various bacteria, and as a result, the bacteria are killed.

  The discharge start voltage required to generate streamer discharge and spark discharge varies depending on the discharge distance, the shape of the discharge electrode, the electrode material, the atmospheric pressure, the humidity, and the like, but generally has the relationship shown in FIG. FIG. 4 shows (1) a plate-like discharge electrode and a plate-like counter electrode, (2) a spherical discharge electrode and a plate-like counter electrode, and (3) a needle-like discharge electrode and a needle-like counter electrode. The graph shows the relationship between the discharge distance and the discharge start voltage for each type. FIG. 4 shows that a distance of 3 to 20 mm per 10 kV is required in order to cause dielectric breakdown in the space by a high voltage, depending on the combination of electrode shapes. For example, when the high-voltage discharge electrode is made spherical and a cultivation container composed of a flat portion and a corner portion is made to conduct to the counter electrode voltage, the high-voltage discharge distance can be set with a standard of 10 kV / 10 mm according to the relationship (2). .

  If the discharge start voltage is 10 kV or more, streamer discharge due to corona discharge occurs, but in the present invention, in order to perform effective sterilization, the discharge start voltage 20-120 kV is necessary, preferably 30-120 kV, More preferably, it is 30-80 kV, More preferably, it is 60-80 kV. If the high voltage discharge is less than 20 kV, the sterilizing ability is insufficient. On the contrary, if it is higher than 140 kV, not only the sterilizing ability is saturated, but also the culture base material is altered, and as a result, the growth of mycelia inoculated by mushrooms is suppressed after sterilization, and the cultivation container and the culture base material burn. This causes problems.

  Culture substrates such as moisture-containing chips are considered electrical conductors. Since the chips in the culture vessel are in contact with each other, all of the contact points become discharge paths, that is, electric conductors. Therefore, since high voltage discharge penetrates to the deep part of a cultivation container, it is possible to give a discharge product to a culture substrate simultaneously with generation.

  The high voltage discharge distance (also referred to as discharge gap) is the sum of the discharge distances between the discharge electrode and / or the counter electrode and the culture substrate, and varies depending on the relationship between the culture substrate and the electrode, which is an electrical conductor. . For example, FIG. 1 shows a state in which the culture substrate is floating from the discharge electrode and the counter electrode, and this high voltage discharge distance is the distance between the discharge electrode and the culture substrate surface and the distance between the culture substrate surface and the counter electrode. Total. In FIG. 2, the culture substrate is in conduction with the counter electrode voltage, and the high-voltage discharge distance is the distance between the discharge electrode and the culture substrate surface. In FIG. 3, the culture substrate is in conduction with the discharge electrode, and the high-pressure discharge distance is the distance between the counter electrode and the culture substrate surface.

  As shown in FIG. 4, the high voltage discharge distance varies depending on the shape of the discharge electrode and the counter electrode, the installation state of the culture substrate, the applied voltage, etc., but is usually 10 to 300 mm, preferably 40 to 40 mm. 150 mm. If the discharge gap is shorter than 10 mm, a large current may flow through the culture substrate and damage the substrate or container. Conversely, if it is longer than 300 mm, streamer discharge and spark discharge effective for sterilization will not occur. A discharge in which spark discharge and streamer discharge are mixed is preferable.

  The point of sterilization in the present invention is to allow the spark discharge to pass through the culture substrate evenly and to give the spark discharge an opportunity for sterilization. The lifetime of the discharge product is as short as 1 μS to 1 ms. In addition, since the electrical resistance of the chip or the like constituting the culture substrate is slightly different mainly due to moisture, the discharge path is also different. Therefore, in order to allow the spark discharge to pass through evenly, a certain number of spark discharges (application time) is required. The longer the application time, the greater the chance of entering everywhere in the cultivation container, but it is usually 10 seconds to 60 minutes, preferably 60 seconds to 10 minutes.

  FIG. 5 shows the positional relationship between the installation form of a plurality of culture vessels and the discharge electrodes. As shown in FIG. 5, a plurality of cultivation containers are juxtaposed on the support member at regular intervals vertically and horizontally. A discharge electrode may be prepared for each cultivation container. As shown in FIG. 5, by rotating the discharge electrode of the high-voltage applying device located above the above-described discharge gap in the vertical and horizontal directions or in an arc from above the cultivation container, a large number of cultivation containers with one or a small number of electrodes are used. Can be sterilized.

  FIG. 6 is an outline in the case where the sterilization step is performed when the culture substrate is filled into the cultivation container. An embodiment is shown in which a discharge space is provided by a discharge electrode and a counter electrode in a culture system (chip) filling system, and sterilization is performed there.

  In FIG. 7, an example of the high voltage generator suitable for using for the cultivation method of the mushroom of this invention is shown. The high voltage generator includes a high voltage generator 10 and a high voltage application unit 30. The high voltage application unit 30 is electrically connected to the discharge side electrode 35 to which the output terminal of the high voltage generation unit 10 is connected, the ground side electrode 36 facing the discharge side electrode 35 via the discharge gap G1, and the ground side electrode 36. The application side electrode 38 is provided. Most of the high voltage application unit 30 is accommodated in the cylindrical body 31, and only the application side electrode 38 is exposed.

  The application side electrode 38 may be electrically connected to the culture substrate, but may be opposed to the culture substrate by opening the second discharge gap G2. In this case, the application side electrode 38 becomes a discharge electrode.

  As shown in FIG. 6, the high voltage application device 1 mainly includes a high voltage generation unit 10, a controller 20, and a high voltage pulse application unit 30. The high voltage generating unit 10 is connected to the controller 20 via the low voltage cable 11 and is connected to the high voltage pulse applying unit 30 via the high voltage cable 12. The controller 20 incorporates a circuit for controlling the setting conditions (output voltage, output current, output cycle, boost time, discharge energy, pulse polarity, plasma application time, etc.) of the high voltage pulse. In addition, circuits for safety functions such as overcurrent detection, overvoltage detection, and temperature detection are appropriately incorporated.

  The high voltage generator 10 can use a Cockcroft-Walton circuit, an electrostatic generator, a Wimshurst generator, a van de Graaf generator, a piezoelectric transformer high voltage generator, or the like.

  A long cylindrical cylinder 31 located in the high voltage application unit 30 is connected to three members, that is, a handheld unit 32, a protective cover 33, and a discharge gap cover 34 to which the protective cover is detachably connected from the left. Has been. The other end side of the high voltage cable 12 is drawn into the cylindrical body 31 from the left end side in the axial direction, extends to the discharge gap cover 34 side, and the spherical discharge side electrode 35 is exposed at the tip thereof. The material of the discharge electrode is preferably difficult to ionize, and is made of, for example, stainless steel, pure copper, gold, silver, titanium, tungsten, or carbon.

  A spherical ground-side electrode 36 is opposed to the discharge-side electrode 35 via the discharge gap G1. The material of the ground side electrode is made of carbon.

  When the discharge side electrode 35 and the ground side electrode 36 are spherical, it is more difficult to discharge than in the case of a needle shape. Thereby, the space | interval of the discharge gap G1 can be narrowed to 20-150 mm normally, Preferably it is 50-100 mm. As a result, the high voltage application unit 30 can be reduced in size.

  The application side electrode 38 (discharge electrode) is exposed from the cylindrical body 31 with the conductive rod-shaped connecting portion 37 sandwiched between the ground side electrode 36 and the opposite side. That is, the ground side electrode 36 of the connecting portion 67 is drawn into the discharge gap cover 34 and only the application side electrode 38 is exposed. The material of the application side electrode is made of carbon. The shape of the application side electrode is preferably spherical.

  As described above, the application-side electrode 38 may be opposed to the culture substrate via the second discharge gap G2. G2 is usually 0 to 100 mm, preferably 0 to 50 mm.

  In the method of the present invention, the interval to be controlled for streamer discharge and spark discharge is the discharge gap G1 between the discharge side electrode and the ground side electrode, and the number between the appropriate application side electrode (discharge electrode) and the culture substrate surface. This is the sum of the two discharge gaps G2. Streamer discharge and spark discharge occur between the discharge side electrode 35 and the ground side electrode 36 (G1) surrounded by the discharge gap cover 34 and between the application side electrode 38 (discharge electrode) and the culture substrate (G2).

The handheld part 32 is comprised with the electrically conductive material, for example, a metal material, and the earth wire is connected. The protective cover 33 is made of an insulator, such as PMMA, PVC, PE, PP, POM, PETP, PFA, PTFE, or the like. The discharge gap cover 34 can be seen through, and is made of the above-described insulator or a semiconductor having a resistance value of about 10 ⁶ to 10 ¹⁰ Ω, such as PMMA, PVC, PETP, or the like. The discharge gap cover prevents the occurrence of high voltage leakage due to moisture or contamination of the surrounding environment.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples of the present invention. However, the present invention is not limited to the following examples.
[Examples 1-6, Comparative Examples 1-3]
A 3 L (surface area: 1280 cm ² × height: 12.5 cm) cultivation container (manufactured by Shinkoen) was filled with a culture substrate (material: oak, 60% water). The high voltage applying device shown in FIG. 7 was used in the mode shown in FIG. And the high voltage discharge was applied to the culture base material in a cultivation container on condition of the following.
Discharge gap (G1) between the discharge side electrode and the installation side electrode: about 10 mm per 10 kV
Second discharge gap (G2) between the application side electrode and the culture substrate: 5 mm
High voltage: Table 1
High voltage application time: 10 minutes n number: 10

  The effect of high voltage electrosterilization was relatively evaluated with the sterilization effect at the time of heat sterilization using the same culture vessel (heated with steam at a constant temperature of 100 ° C. for 4 hours) as 100. The results are shown in Table 1.

* Sterilization effect: Relative value of high-voltage electrosterilization when the effect of heat sterilization is 100%

  As shown in Table 1, by applying a high-voltage discharge of 20 kV to the culture substrate in Example 1, the sterilization effect of the culture substrate appeared significantly. The sterilization effect was shown so that all the conventional steam sterilization processes could be substituted at 60 kV or more of Examples 3 to 6. However, the high voltage of 140 kV in Comparative Example 3 inhibited mycelial growth. Therefore, in order to suppress the propagation of germs and promote the growth of mycelia, a high voltage of 20 to 120 kV is required, preferably 30 to 120 kV, more preferably 30 to 80 kV, and even more preferably 60 to 80 kV. It turned out to be.

In order to further verify the above results, the following tests were conducted. First, after allowing various bacteria to adhere to a Petri dish (10 cm ² ) on which an agar medium was spread, a high voltage of 100 kV was applied for 10 minutes using the high voltage application device of FIG. At this time, the distance between the discharge electrode and the culture substrate was 100 mm. For comparison, a control sample was prepared by attaching various bacteria to a Petri dish on which an agar medium was spread and then applying no voltage. A high-voltage agar medium and a control agar medium were cultured at 35 ° C. and a humidity of 80% RH for 1 day. A photograph of the agar medium after storage is shown in FIG. As shown in FIG. 9, miscellaneous bacteria propagated on the agar medium to which no high voltage was applied, but the propagation of miscellaneous bacteria was remarkably suppressed when the high voltage was applied. By applying a high voltage, it was proved that propagation of miscellaneous bacteria was suppressed, and mushroom cultivation was possible without performing heat sterilization of the medium substrate.

DESCRIPTION OF SYMBOLS 1 ... High voltage application apparatus 10 ... High voltage generation part 11 ... Low voltage cable 12 ... High voltage cable 20 ... Controller 30 ... High voltage pulse application part 31 ... Cylindrical body 32 ... Hand-held part 33 ... Protective cover 34 ... Discharge gap cover 35 ... Discharge side electrode 36 ... Ground side electrode 37 ... Communication part 38 ... Apply side electrode (discharge electrode)
G1 ... discharge gap G2 ... second discharge gap X ... cultivation container Y ... culture substrate

Claims (6)

In cultivation method of mushrooms, it viewed including the step of sterilizing the culture substrate by applying a high voltage discharge of 20kV~120kV the culture substrate,
The high voltage discharge includes a high voltage generation unit (10) and a high voltage application unit (30), and the high voltage application unit includes a discharge side electrode (35) to which an output terminal of the high voltage generation unit is connected. A high-voltage applying device comprising: a ground-side electrode (36) opposed to the discharge-side electrode (35) via a discharge gap; and an application-side electrode (38) electrically connected to the ground-side electrode (36) The high voltage application unit (10) is housed in a cylindrical body (31), and only the application side electrode (38) is exposed. And
The method for cultivating the mushroom, wherein the discharge side electrode (35) and the ground side electrode (36) are spherical in shape .   The high-voltage discharge is applied to the culture substrate by interposing the culture substrate between a high-voltage discharge electrode and a counter electrode, and applying a high voltage between the discharge electrode and the counter electrode. The method for cultivating mushrooms according to claim 1, wherein the cultivation is performed by generating streamer discharge or spark discharge, and at this time, the high voltage discharge distance is 3 to 20 mm per 10 kV.   The application method of the said high voltage discharge is the cultivation method of the mushroom of Claim 1 or 2 which is 10 second-60 minutes.   The method for cultivating mushrooms according to any one of claims 1 to 3, wherein the sterilizing step is performed after filling the culture substrate into a cultivation container.   The method for cultivating mushrooms according to any one of claims 1 to 3, wherein the sterilizing step is performed when the culture substrate is filled into a cultivation container. Sterilizing the culture substrate by applying a high voltage discharge of 20 kV to 120 kV to the culture substrate ;
The high voltage discharge includes a high voltage generation unit (10) and a high voltage application unit (30), and the high voltage application unit includes a discharge side electrode (35) to which an output terminal of the high voltage generation unit is connected. A high-voltage applying device comprising: a ground-side electrode (36) opposed to the discharge-side electrode (35) via a discharge gap; and an application-side electrode (38) electrically connected to the ground-side electrode (36) The high voltage application unit (10) is housed in a cylindrical body (31), and only the application side electrode (38) is exposed. And
The method for treating a mushroom culture substrate, wherein the discharge-side electrode (35) and the ground-side electrode (36) are spherical in shape .