Method for producing cultivation medium

Abstract

To provide a method for producing a cultivation medium that can sterilize the cultivation medium effectively and quickly.SOLUTION: Provided is a method for producing a cultivation medium, comprising: a moisture supplying step of supplying moisture to a fiber-containing raw material to produce a moisture-containing raw material; a depressurizing step of reducing the pressure of the atmosphere surrounding the moisture-containing raw material to between 3,200 Pa and 50,000 Pa; and an ozone treatment step of applying ozone to the moisture-containing raw material in the atmosphere to perform ozone treatment. Furthermore, the moisture content of the moisture-containing raw material produced in the moisture supplying step is preferably between 1 wt.% and 40 wt.%.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for producing a cultivation medium. [Background technology]

[0002] Artificial cultivation media for cultivating mushrooms and the like have been known for some time. For example, Patent Document 1 discloses a fungal bed medium for growing Matsutake mushrooms, which has a structure consisting of medium components including a base material such as sawdust and voids. After producing such a medium, sterilization is performed to make it sterile, allowing for good cultivation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-178686 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the sterilization process is carried out using a commonly known sterilization method, there is a problem in that it takes a long time to achieve uniform and good sterilization. [Means for solving the problem]

[0005] The method for producing a culture medium of the present invention includes a water supplying step of supplying water to a fiber-containing raw material to produce a water-containing raw material; a decompression step of reducing the pressure of the atmosphere of the moisture-containing raw material to 3200 Pa or more and 50000 Pa or less; and an ozone treatment step of applying ozone to the moisture-containing raw material in the atmosphere to perform ozone treatment. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a culture medium. [Figure 2] FIG. 2 is a diagram showing a schematic diagram of a production device and production process for a culture medium. DETAILED DESCRIPTION OF THE INVENTION

[0007] The method for producing a culture medium of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.

[0008] First Embodiment Fig. 1 is a cross-sectional view showing an example of a culture medium, and Fig. 2 is a diagram showing a schematic diagram of a production device and production process for a culture medium.

[0009] As shown in FIG. 1, a cultivation medium 1 is a medium for cultivating fungi such as mushrooms, and has a sheet S containing fibers, particularly cellulose fibers.

[0010] It should be noted that the things cultivated in the cultivation medium 1 are not limited to mushrooms, but may also be, for example, vegetables, etc. Hereinafter, the cultivation medium 1 will be described as a medium for cultivating mushrooms.

[0011] To cultivate mushrooms, mushroom mycelium K is spread over the entire cultivation medium 1 (sheet S), placed in a culture container (hereinafter simply referred to as "container 10") and cultivated, and a cultivation process is carried out in which the mycelium K grows; and a generation process is carried out in which the cultivation medium 1 with the mycelium K cultivated over the entire surface is removed from the container 10 and fruiting bodies are generated.

[0012] When carrying out the culture process, first, the culture medium 1 is placed in a container 10, and mycelia K or spores are sprayed onto the culture medium 1. The spraying method is not particularly limited, but examples include a method in which a dispersion of mycelia K or spores in water is sprayed over the entire surface using a spray bottle or the like. This allows the mycelia K to be maintained uniformly, i.e., evenly, on the culture medium 1.

[0013] The mycelium K is maintained so as to be evenly distributed throughout the entire cultivation medium 1, and as this mycelium K grows, the cultivation medium 1 becomes less susceptible to mold and bacteria in the outside air, which promotes the growth of fruiting bodies during the development process. When the cultivation process is complete, the mycelium K will turn brown or white over the entire surface of the cultivation medium 1. This phenomenon serves as an indication that the cultivation process is complete. The color will vary depending on the type of mushroom.

[0014] Mushrooms to be cultured on the cultivation medium 1 are not particularly limited, and examples thereof include Aishimeji, Aitake, Akayamadori, Akebonoawatake, Akebonosakurashimeji, Morel, Amitake, Amihanaiguchi, Irogawari, Usutake, Usuhiratake, Urabenigasa, Urabenihoteishimeji, Flammulina, Pleurotus eryngii, Asparagus mushroom, Ginkgo biloba, Gomutake, Tsugatake, Otomenokasa, and Ono. Ninaratake mushroom, Onifusa nigra, Kawarihata mushroom, Daylily mushroom, Yellow croaker, Kushigasa mushroom, Kinumerigasa mushroom, Kugitake mushroom, Kuritake mushroom, Chestnut matsutake, Black kawa, Black trumpet mushroom, Kojitake mushroom, Kotake mushroom, Koganetake mushroom, Kozaraminoshimeji, Sakurashimeji, Saketsubatake mushroom, Coprinus comatus, Shiitake mushroom, Shimofurishimeji, Shakashimeji, Shogenji mushroom, White wood ear mushroom, White nametsumu mushroom, White slime mushroom Boletus, Sugiedatake, Susukeyamadoritake, Tamaurabenitake, Tamagotake, Tamogitake, Nittotake, Chanamatsutake, Earth chestnut, Tsubabushimeji, Tsugarimigasatake, Truffle, Nagaenosugitake, Nameko, Armillaria, Nihonshimeji, Nishikitake, Ningyotake, Slimy boletus, Slimy sasatake, Slimy sugitake, Slimy sugitake false, Slimy tsubatake, Noutake, Noboriryu Examples include Utake, Hatakeshimeji, Hattake, Hanaiguchi, Hanabiratake, Hanabiranikawatake, Harushimeji, Oyster mushroom, Bunashimeji, Bunaharitake, Fuyuyamatake, Houkitake, Hoteishimeji, Hokotake, Maitake, Matsuouji, Matsutake, Mukitake, Purple shiitake, Purple boletus, Morinofujiirotake, Yamaguchi, Boletus edodes, Boletus pseudo-boletus, and Yamabushitake.

[0015] Examples of the container 10 include a tray, a petri dish, a flask, and a well plate. The material of the container 10 is not particularly limited, but it is preferably made of a hard material. Examples of hard materials include a hard resin material and a glass material. When the container 10 is made of a hard material, it is easy to form a portion through which air can be introduced into the culture medium 1 contained therein. For example, a hole can be formed in a portion of the container 10, and a HEPA filter or the like can be installed in the hole. This ensures breathing of various fungi and mushroom mycelia K contained in the culture medium 1 and prevents mold from entering the container 10. Another advantage is that the interior of the container 10 can be easily sterilized at high temperature and pressure before the mushroom mycelia K are sprayed.

[0016] The container 10 may be soft or flexible, such as a bag made of resin.

[0017] The cultivation medium 1 is a sheet S made of a material containing cellulose fiber, and contains nutrients C. Note that the nutrients C may be omitted.

[0018] The sheet S may be a stack of multiple sheets, or may be a lump formed by forming wrinkles on each sheet. The cultivation medium 1 may also contain coarsely crushed pieces of the sheet S, for example, by a shredder.

[0019] By using the sheet S as the cultivation medium 1, as described above, gaps can be formed between the sheets S, thereby improving breathability. Furthermore, by including cellulose fibers in the sheet S, the breathability of the sheet S itself can be improved. Therefore, these synergistic effects can promote mushroom cultivation, enabling proper and satisfactory mushroom cultivation.

[0020] In addition, cellulose fibers are easily available, and their use is preferable from the viewpoints of environmental issues and saving natural resources, and is advantageous in terms of raw material procurement and cost. Furthermore, among various fibers, cellulose fibers have a high theoretical strength, and can improve the strength and shape retention of the cultivation medium 1.

[0021] Examples of cellulose fibers include wood cellulose fibers derived from softwoods and hardwoods; seed fiber cellulose fibers from cotton, linter, kabak, etc.; bast cellulose fibers from hemp, ramie, paper mulberry, etc.; and leaf stem cellulose fibers from banana and Manila hemp, etc. While one or a combination of two or more of these can be used, it is preferable to use wood cellulose fibers as the main component. Wood cellulose fibers are readily available in the form of pulp. Examples of pulp include virgin pulp, kraft pulp, chemithermomechanical pulp, synthetic pulp, and pulp derived from waste or recycled paper, and one or a combination of two or more of these can be used. Here, cellulose fibers refer to any fibrous material composed primarily of cellulose as a compound, i.e., cellulose in the narrow sense. Examples of cellulose fibers include regenerated cellulose such as rayon and cupra, as well as hemicellulose and lignin.

[0022] The cellulose fibers are preferably derived from waste paper or recycled paper. This is advantageous from the viewpoints of waste reduction, effective resource utilization, forest conservation, environmental protection, etc. Waste paper is used paper to which ink or the like has been applied. Recycled paper is paper made by recycling waste paper or virgin paper.

[0023] The average fiber length of the cellulose fibers is not particularly limited, but is preferably 0.1 mm or more and 5 mm or less, and more preferably 0.2 mm or more and 3 mm or less. This improves breathability and makes it easier to maintain the shape of the cultivation medium 1. It also contributes to promoting the growth of the mycelia K. As a result, the mycelia K can be cultivated more effectively and quickly. The average fiber length of the cellulose fibers can be measured, for example, by the staple diagram method.

[0024] From the same viewpoint, the average diameter (average width) of the cellulose fibers is not particularly limited, but is preferably 0.5 μm or more and 200 μm or less, and more preferably 1.0 μm or more and 100 μm or less, which allows the mycelium K to be cultured more satisfactorily and quickly.

[0025] From the same viewpoint, the average aspect ratio of the cellulose fibers (ratio of average length to average width) is not particularly limited, but from the same viewpoint as the fiber length, it is preferably 10 or more and 1000 or less, and more preferably 15 or more and 500 or less. This allows the mycelium K to be cultured more effectively and quickly.

[0026] The above-mentioned preferable conditions such as average fiber length, average diameter (average width), average aspect ratio, etc. are also applicable to fibers other than cellulose fibers.

[0027] The content of cellulose fibers in the sheet S is not particularly limited, but is preferably 50% by weight or more and 97% by weight or less, and more preferably 60% by weight or more and 85% by weight or less, so that the above-mentioned effects of including cellulose fibers can be more significantly exhibited.

[0028] The sheet S may contain a binder B. The binding material B functions as a binder that partially binds the defibrated cellulose fibers together. The presence of such binding material B ensures that the sheet S has sufficient strength and maintains its shape. This means that the cultivation medium 1 can maintain sufficient shape while maintaining the necessary breathability. This contributes to the successful and rapid cultivation of mycelia K.

[0029] Starch is suitable as binder B. When exposed to moisture and heat, starch gelatinizes and develops binding power. Starch is derived from natural products, which is advantageous for reducing environmental impact. In addition, it also functions as a nutrient source for mushrooms and a water-retaining agent for Sheet S.

[0030] The content of binder B in the sheet S is not particularly limited, but is preferably 0.3% by weight to 50% by weight, and more preferably 1.0% by weight to 30% by weight, so that the above-mentioned effects of including binder B can be exerted necessary and sufficiently.

[0031] The binder B can be added to the deposit M during the deposit supply step described below, or before or during the sheet S forming step.

[0032] The nutrient C has the function of supplying nutrients to the mycelium K and promoting the growth of the mycelium K. Examples of nutrients C include nitrogen fertilizers such as ammonium sulfate, ammonium chloride, and ammonium nitrate, phosphate fertilizers such as superphosphate, triple superphosphate, and fused phosphate fertilizer, potassium fertilizers such as potassium chloride and potassium nitrate, soybean meal, rice bran, wheat bran, chicken manure, horse manure, etc. Other examples include chicken matter (shells of crustaceans such as shrimp and crab, and exoskeletons of arthropods such as insects), and nutrients contained in foods for specified health uses (e.g., DHA and EPA).

[0033] By including the nutrient C in the sheet S, nutrients can be supplied to the mycelia K in the cultivation medium 1, allowing for better and faster cultivation of the mycelia K. In particular, the effort required to separately spray the nutrient C on the cultivation medium 1 is also reduced.

[0034] The content of the nutrient C in the sheet S is not particularly limited, but is preferably 0.1% by weight to 40% by weight, and more preferably 1.0% by weight to 20% by weight, so that the above-mentioned effects of including the nutrient C can be more effectively and effectively achieved. The sheet S may not substantially contain the nutrients C.

[0035] The cultivation medium 1 may contain various additives in addition to the cellulose fiber, binder B, and nutrients C. Examples of the various additives include soil conditioners, pest repellents and insecticides, water retention agents, lactic acid bacteria and fermentation promoters, and ash.

[0036] Examples of soil conditioners include pH adjusters such as organic lime, wood ash, quicklime, and slaked lime.

[0037] Examples of pest repellents and insecticides include known chemically synthesized agents such as camphor and naphthalene, and natural materials such as camphor wood flour and cypress wood flour. These agents and natural materials may be used alone or in combination.

[0038] Examples of water-retaining agents include acrylic acid-vinyl alcohol copolymers, alkaline hydrolysates of starch-acrylonitrile graft copolymers, sodium acrylate polymers, and mixtures of multiple types of water-absorbent polymers.

[0039] Lactic acid bacteria inhibit the activity of mold and aerobic bacteria, which cause spoilage. Fermentation accelerators in Sheet S promote the activity of microorganisms such as lactic acid bacteria.

[0040] Examples of ash include charcoal, bamboo charcoal, and charcoal made from oak shells. Ash can be used with the sheet S to suppress the growth of bacteria and insects.

[0041] The addition of the nutrients C and other various additives to the sheet S may be carried out before, during, or after each of the sheet S forming process, moisture supply process, pressure reduction process, and ozone treatment process described below.

[0042] Next, the cultivation medium production apparatus 100 for carrying out the cultivation medium production method of the present invention and each step of the cultivation medium production method using the cultivation medium production apparatus 100 will be described with reference to FIG.

[0043] As shown in Figure 2, the cultivation medium manufacturing apparatus 100 includes a deposit supply unit 2 that supplies a deposit M of defibrated cellulose fibers, a forming unit 3 that forms the deposit M into a sheet S, a moisture supply unit 4, and a sterilization unit 5 that performs a sterilization treatment. The deposit supply unit 2, the forming unit 3, the moisture supply unit 4, and the sterilization unit 5 are arranged in this order from the upstream side to the downstream side of the path along which the raw material sheet S and the moisture-containing raw material SW travel. In the following explanation, the upstream side and downstream side of the path along which the sheet S travels will simply be referred to as the "upstream side" and the "downstream side."

[0044] The configuration of the deposit supply unit 2 can be, for example, the configuration of the crushing unit, defibrating unit, and depositing unit of a sheet manufacturing apparatus as described in JP 2022-176652 A. The deposit supply step is performed by this deposit supply unit 2. The deposit M supplied by the deposit supply unit 2 is formed into a sheet S by the forming unit 3.

[0045] A forming unit 3 is installed downstream of the deposit supply unit 2. The forming unit 3 is a part that carries out a forming process of forming the deposit M into a sheet S, and includes a heating unit 31, a pressurizing unit 32, and a cutting unit 33.

[0046] The heating unit 31 irradiates microwaves toward the deposit M, thereby vibrating the moisture contained in the deposit M and heating the deposit M through the vibrations. This melts the binder B contained in the deposit M and bonds the cellulose fibers together.

[0047] The frequency of the microwave is not particularly limited, but is preferably 1 GHz or more and 100 GHz or less, and more preferably 2 GHz or more and 70 GHz or less, which allows the deposit M to be heated more effectively.

[0048] The microwave irradiation time is not particularly limited, but is preferably from 5 to 120 seconds, and more preferably from 10 to 60 seconds, which allows the deposit M to be heated more effectively.

[0049] It is more preferable to irradiate the deposit M with microwaves having a frequency in the above-mentioned preferred range for an irradiation time in the above-mentioned preferred range, thereby making it possible to heat the deposit M more effectively.

[0050] In this way, the deposit M is heated by irradiating it with microwaves. This allows the deposit M to be heated efficiently while reducing damage to the cellulose fibers and other components contained in the deposit M.

[0051] In the present invention, the heating of the deposit M by the heating section 31 is not limited to a method using microwave irradiation, but may be other heating methods, such as heating using a heater such as a heat roller, or heating using infrared irradiation or laser light irradiation.

[0052] A pressure applying unit 32 is provided downstream of the heating unit 31. The pressure applying unit 32 has a pair of rollers 321. The rollers 321 are arranged side by side in the vertical direction in FIG. 2, and when the pile M passes between the rollers 321, the pile M is pressed by the rollers 321. This causes the pile M to be compressed in the thickness direction, and a sheet S is produced.

[0053] It should be noted that by using a heat roller as the roller 321, heating and pressure can be applied simultaneously.

[0054] As in this embodiment, applying pressure using a pair of rollers 321 has the advantage of being able to continuously produce sheets S from the pile M, but the present invention is not limited to this, and may be configured, for example, to apply pressure to the pile M in a batchwise manner using a pair of upper and lower pressure plates. In this case, by using a heating plate as the pressure plate, heating and pressure can be performed simultaneously.

[0055] A cutting unit 33 is provided downstream of the pressure applying unit 32. The cutting unit 33 has a pair of cutting blades 331. The cutting blades 331 are arranged side by side in the vertical direction in FIG. 2, and the sheet S passing between the cutting blades 331 is cut to a predetermined length by the cutting blades 331 moving toward and away from each other.

[0056] A moisture supplying section 4 is installed downstream of the forming section 3. The sheet S formed by the forming section 3 is supplied with moisture by the moisture supplying section 4. The moisture supplying section 4 is a section that executes a moisture supplying step of supplying moisture to the sheet S to produce the moisture-containing raw material SW. The moisture supplying section 4 sprays water toward the sheet S in a spray-like manner.

[0057] The moisture content of the moisture-containing raw material SW produced in the moisture supplying step, i.e., the moisture-containing raw material SW to which moisture has been added by the moisture supply unit 4, is not particularly limited, but is preferably 1% by weight to 40% by weight, more preferably 1% by weight to 40% by weight, which allows for better and more efficient sterilization of the sheet S in the ozone treatment in the ozone treatment step described below.

[0058] Thus, the moisture content of the moisture-containing raw material SW produced in the moisture supplying step is 1% by weight or more and 40% by weight or less, which allows the sheet S to be sterilized more effectively and efficiently by the ozone treatment described below.

[0059] The moisture supply unit 4 is not limited to a configuration that sprays water in a spray-like manner, but may be configured to supply moisture to the sheet S by immersing the sheet S in water or an aqueous solution, or may be configured to supply moisture to the sheet S by supplying humidified air.

[0060] A sterilization unit 5 is installed downstream of the moisture supply unit 4. The sterilization unit 5 sterilizes the moisture-containing raw material SW, i.e., the sheet S, by carrying out a depressurization step and an ozone treatment step. In this embodiment, the depressurization step and the ozone treatment step are carried out in this order in the same sterilization unit 5 without any overlap in time. In this specification, sterilization refers to reducing the survival rate of microorganisms and viruses to 1% or less compared to before treatment.

[0061] The sterilization unit 5 has a chamber 51, a vacuum pump 52, a heater 53, a fan 54, and an ozone supply unit 55. The vacuum pump 52 is also called an exhaust pump.

[0062] The chamber 51 is a container that can ensure airtightness. Although not shown, the chamber 51 has an inlet for taking in the moisture-containing raw material SW and an outlet for taking out the moisture-containing raw material SW that has been ozone-treated. The inlet and outlet can each be opened and closed, and when open, the moisture-containing raw material SW can be introduced and removed, while when closed, the chamber 51 can maintain its airtightness. The inlet and outlet may be the same, i.e., common.

[0063] In addition to the intake and outlet ports, the chamber 51 has a suction port 511 to which a decompression pump 52 is connected, and a supply port 512 to which an ozone supply unit 55 is connected.

[0064] When the decompression step and the ozone treatment step are performed, the moisture-containing raw material SW is stored and arranged in the chamber 51. The number of moisture-containing raw material SW arranged may be one or more. In the case of more than one raw material SW, it is preferable that they are arranged and held in a state spaced apart from each other by a holder such as a rack (not shown).

[0065] In the sterilization section 5, after the moisture-containing raw material SW is placed in the chamber 51, the decompression pump 52 is operated to exhaust the gas in the chamber 51 through the pipe 521, thereby reducing the pressure of the atmosphere. That is, a decompression step is performed. When the operation of the decompression pump 52 is stopped, the flow of gas through the flow path of the pipe 521 is blocked.

[0066] In the depressurization step, the pressure inside the chamber 51, i.e., the pressure of the atmosphere surrounding the moisture-containing raw material SW, is reduced. In the present invention, the pressure of the atmosphere surrounding the moisture-containing raw material SW is reduced to 3200 Pa or more and 50000 Pa or less. This allows for uniform and good sterilization in the ozone treatment described below. If the pressure of the atmosphere surrounding the moisture-containing raw material SW is too low or too high, it will be disadvantageous to uniform and rapid sterilization in the ozone treatment described below.

[0067] An open / close valve or a variable flow rate valve that can select whether or not to allow gas to flow can also be provided in pipe 521. When a variable flow rate valve is provided, the speed at which the pressure in chamber 51 is reduced can be adjusted.

[0068] As a result, when the gas exhausted to the outside of the chamber 51 contains ozone, the ozone odor in the environment outside the chamber 51 can be reduced.

[0069] In the sterilization unit 5, the ozone supply unit 55 is operated to supply ozone through the pipe 551 in an atmosphere where the pressure inside the chamber 51 is reduced to between 3200 Pa and 50000 Pa. In other words, the ozone treatment step is performed. As a result, ozone is applied to the moisture-containing raw material SW, the moisture-containing raw material SW is treated with ozone, and the moisture-containing raw material SW is sterilized.

[0070] Supplying ozone into chamber 51 causes a slight increase in the pressure inside chamber 51. After ozone is supplied, i.e., during ozone treatment, the pressure inside chamber 51 is lower than atmospheric pressure, and is preferably between 4000 Pa and 55000 Pa, and more preferably between 4500 Pa and 54500 Pa. This allows a sufficient amount of ozone to be supplied into chamber 51, thereby enabling better sterilization of the water-containing raw material SW.

[0071] In this way, the pressure of the atmosphere around the water-containing raw material SW during ozone treatment in the ozone treatment step is 4000 Pa or more and 55000 Pa or less. This allows a sufficient amount of ozone to be supplied to the chamber 51, and the water-containing raw material SW can be sterilized more effectively.

[0072] The ozone supply unit 55 has an ozone generation source. The ozone generation source is not particularly limited, and examples thereof include a method of irradiating oxygen with high-energy light such as an electron beam, radiation, or ultraviolet light, a chemical method, an electrolysis method, a discharge method, or the like to generate ozone.

[0073] Furthermore, the ozone supply unit 55 may have an air supply means, such as a fan, that supplies ozone generated in the ozone generation source into the chamber 51 through the pipe 551 .

[0074] In the present invention, unlike the configuration shown in FIG. 2, the ozone supply unit 55, particularly the ozone generation source, may be installed inside the chamber 51.

[0075] The ozone concentration in the atmosphere during ozone treatment in chamber 51 is not particularly limited, but is preferably 0.01% by volume or more and 1.0% by volume or less, and more preferably 0.1% by volume or more and 0.9% by volume or less. This allows for just the right amount of ozone treatment, enabling faster and better sterilization.

[0076] In this way, by subjecting the moisture-containing raw material SW to ozone treatment, ozone dissolves in part of the moisture in the moisture-containing raw material SW, forming ozone water. This ozone water can sterilize the sheet S more effectively and quickly. Furthermore, since the ozone treatment is performed after the pressure in the chamber 51 is reduced to between 3,200 Pa and 50,000 Pa, the ozone diffuses more uniformly and quickly within the chamber 51, allowing for uniform and good sterilization in a shorter time. As described above, according to the present invention, the sheet S can be sterilized efficiently and quickly.

[0077] A heater 53 and a fan 54 are provided at the top of the chamber 51. The heater 53 has a heating element that generates heat when electricity is applied. This makes it possible to increase the temperature inside the chamber 51, and even when the ambient temperature is low, such as in winter, ozone treatment can be performed at an appropriate temperature, as described below.

[0078] The temperature of the atmosphere in the chamber 51 can be adjusted appropriately by controlling the operation of the heater 53 .

[0079] The ozone treatment time is not particularly limited, but the sheet S can be sterilized with a treatment of about 10 minutes.

[0080] The fan 54 has a motor that rotates when energized and a rotating blade that rotates when driven by the motor. The rotation of the rotating blade generates an air current within the chamber 51, which can agitate the atmosphere. This agitation of the atmosphere can make the temperature and ozone concentration of the atmosphere within the chamber 51 more uniform. As a result, the sterilization of the sheets S can be performed more uniformly, effectively, and quickly.

[0081] The operation timing of the heater 53 and the fan 54 is not particularly limited, and may or may not overlap with at least one of the decompression step and the ozone treatment step.

[0082] In the present invention, the decompression step and the ozone treatment step can be collectively referred to as the sterilization step. The ozone treatment step can also be referred to as the sterilization step, in which case the decompression step can be referred to as a preliminary sterilization step or a pre-sterilization step.

[0083] The sterilization section 5 does not necessarily have to have at least one of the heater 53 and the fan 54.

[0084] As explained above, the method for producing a culture medium includes a moisture supplying step of supplying moisture to a sheet S, which is a raw material containing fibers, to produce a moisture-containing raw material SW, a depressurizing step of reducing the pressure of the atmosphere around the moisture-containing raw material SW to between 3200 Pa and 50000 Pa, and an ozone treatment step of applying ozone to the moisture-containing raw material SW in the atmosphere to perform ozone treatment. This allows for good and rapid sterilization of the sheet S.

[0085] In this embodiment, the depressurization step and the ozone treatment step are performed in this order without overlapping in time. However, this is not limiting, and the depressurization step and the ozone treatment step may overlap in time partially. That is, the start time of the ozone treatment step may be later than the start time of the depressurization step and earlier than the end time of the depressurization step. The same applies to the water supply step and the depressurization step with respect to the overlap in time of the steps.

[0086] The raw material used in the method for producing the cultivation medium is a sheet S, which is a fiber deposit M, particularly a cellulose fiber deposit, that is heated and pressurized to form it into a sheet. This increases the breathability of the cultivation medium 1 and makes it easier to maintain the shape of the cultivation medium 1. It also contributes to promoting the growth of mycelia K. As a result, mycelia K can be cultivated more effectively and quickly.

[0087] Although the method for producing a medium for mushroom cultivation according to the present invention has been described above as an embodiment, the present invention is not limited thereto. Furthermore, each step in the method for producing a medium for mushroom cultivation can be replaced with any step that can exert a similar function. Furthermore, any step may be added. [Explanation of symbols]

[0088] 1...cultivation medium, 2...deposit supply section, 3...shaping section, 4...moisture supply section, 5...sterilization section, 10...container, 31...heating section, 32...pressurizing section, 33...cutting section, 51...chamber, 52...vacuum pump, 53...heater, 54...fan, 55...ozone supply section, 100...cultivation medium manufacturing device, 321...roller, 331...cutting blade, 511...suction port, 512...supply port, 521...pipe, 551...pipe, B...binder, C...nutrient, K...mycelium, M...deposit, S...sheet, SW...moisture-containing raw material

Claims

1. a moisture supplying step of supplying moisture to a fiber-containing raw material to produce a moisture-containing raw material; a decompression step of reducing the pressure of the atmosphere of the moisture-containing raw material to 3,200 Pa or more and 50,000 Pa or less; and an ozone treatment step of applying ozone to the water-containing raw material under the atmosphere to perform ozone treatment.

2. The method for producing a culture medium according to claim 1, wherein the moisture content of the water-containing raw material produced in the moisture supplying step is 1% by weight or more and 40% by weight or less.

3. The method for producing a culture medium according to claim 1 or 2, wherein the pressure of the atmosphere of the water-containing raw material during the ozone treatment in the ozone treatment step is 4000 Pa or more and 55000 Pa or less.

4. The method for producing a cultivation medium according to claim 1 or 2, wherein the raw material is formed into a sheet by heating and pressurizing a deposit of the fibers.

5. The method for producing a culture medium according to claim 4, wherein the heating is performed by irradiating with microwaves.

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