JPH0438366B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a signal culture medium used for artificial cultivation of mushrooms. [Prior Art] In recent years, the following artificial cultivation methods have been used to cultivate mushrooms such as shiitake mushrooms. That is, first, a mushroom culture medium mixed with sawdust, rice bran, etc. and added with water is filled into a culture bag made of plastic such as polypropylene, and sterilized to create an artificial culture medium for mushrooms. Next, the inoculum is planted in an artificial culture medium for mushrooms, and the mycelium is spread under temperature control to produce a large amount of edible mushrooms. The key to artificially cultivating mushrooms is how to prevent the invasion of bacteria and create an environment suitable for mushroom growth.
A sterilization pot has been installed, and the seeds are planted in a sterile environment such as a clean bench. However, even if the mushroom culture medium is sterilized using high-pressure steam in a sterilization pot, after sterilization, the 90%
The mushroom culture medium is taken out at a high temperature of about 30°C and cooled in the open air for about half a day until the temperature drops to below 30°C, and then the inoculum is inoculated, which causes the invasion of various bacteria. For this reason, sterile rooms are set up to cool the mushroom culture medium, but this requires a large amount of investment, and even with a large amount of investment, bacteria attached to workers' clothes, hair, etc. are brought in. Put it away. Therefore, as a method for producing an artificial culture medium for mushrooms, after filling a culture bag with a mushroom culture medium, both the shoulder of the cap, which fixes the cap, and the breathable cap, which has a sponge attached to the top plate, are inserted into the opening of the culture bag. A method has been proposed to reduce equipment investment and prevent bacterial contamination by attaching the device in advance, sterilizing it with high-pressure steam, and cooling it. That is, the seventh
Using a transparent culture bag 1 made of polypropylene film as shown in the figure, pass its upper opening into a ring-shaped shoulder cap 2 and fold it back to the outside.In this state, insert a cap 4 having a filter 3 inside into the shoulder cap. The culture bag 1 is fitted into the culture bag 2 and sealed, and the culture bag 1 is sterilized with high-pressure steam and cooled while preventing bacteria from entering the culture bag 1. In this case, ventilation is performed through a filter 3 provided in the steam cap 4, and air from which germs have been removed by the filter 3 enters the culture bag 1. However, the operation of inserting the upper opening of the culture bag 1 into the shoulder cap 2, folding it back to the outside, and fitting the cap 4 with the built-in filter 3 therein is complicated and extremely difficult to automate. The reality is that we rely on manual labor. This causes high manufacturing costs, and the capsule itself is also expensive. A culture bag 6 with a filter 3 attached to the side of the culture bag as shown in FIG. 8 instead of the culture bag 1 described above.
There is also a method of filling the culture bag 6 with the mushroom culture medium 5, sealing the opening, sterilizing it with high-pressure steam, cooling it, cutting out the sealed part with scissors, etc., and planting the seed fungus. Proposed. However, attaching such an expensive filter 3 to the disposable culture bag 6 not only increases the cost of the culture bag 6, but also increases the risk of the culture bag rupturing due to poor ventilation during high-pressure steam sterilization, or the high-pressure steam During sterilization, the air contained in the culture bag 6 and the mushroom culture medium 5 is exhausted, but when returning to normal pressure after high-pressure steam sterilization, sufficient air is not taken in, and the mushroom culture medium 5 is removed from the culture bag 6. The phenomenon of being compressed into vacuum packs occurs frequently, making it impossible to produce stable artificial culture media for mushrooms. In addition, the top of the culture bag 6 swells due to internal pressure, and the top surface of the mushroom culture medium 5 and the culture bag 6
As a result, a head space 7 was formed, and the condensation on the inner surface of the culture bag was extremely condensed into the mushroom culture medium 5, causing bacterial contamination. On the other hand, instead of devising the mushroom culture bag as described above, as shown in FIG. 9, a mushroom culture medium 5 is filled in a normal polypropylene transparent film bag 1, and the opening of the culture bag is secured with a rubber ring or the like. A method has also been proposed in which the culture bag is tied with a string-like body 8 or fastened with a scissor jig, adhesive tape, etc., sterilized with high-pressure steam, and after cooling, the culture bag is opened again and the inoculum is planted. However, this method also inevitably requires complicated manual work, and also causes problems such as rupture of the culture bag due to poor ventilation during high-pressure steam sterilization, shrinkage of the vacuum pack, and the top surface of the mushroom culture medium 5. The head space formed by the culture bag 1 could not be eliminated. As described above, in the conventional method for producing an artificial culture medium for mushrooms, it has been difficult to prevent the invasion of various bacteria during the process of high-pressure steam sterilization and cooling, and to obtain an artificial culture medium at a low cost. [Problems to be Solved by the Invention] The present invention was made in view of the above circumstances, and its purpose is to simplify the conventional complicated manual work and eliminate the need for special expensive equipment. , reduce raw material costs such as caps with filters,
Moreover, it is an object of the present invention to provide a method for producing an artificial culture medium for mushrooms that can be put to practical use in conventional mushroom production facilities. Another object of the present invention is to prevent the invasion of germs during the process of high-pressure steam sterilization and cooling, and to prevent the rupture of the culture bag of the artificial culture medium during high-pressure steam sterilization, the shrinkage of the vacuum pack-like shape after high-pressure steam sterilization, and the prevention of the head. To provide a method for producing a stable artificial culture medium for mushrooms, which can be given appropriate air permeability and shape retention to prevent the formation of spaces. Further objects and effects of the present invention will become apparent from the following description. [Means for solving the problem] The above object is to produce an artificial culture medium for mushrooms by filling a containing material made of a film-like material with a mushroom culture medium, and then using an arbitrary direction parallel to the opening surface as a reference. Then, the corresponding opening walls of the container material are overlapped and closed, the overlapped part is folded along the surface of the mushroom culture medium, the folded part is held down with an air permeable holding device, and heated and sterilized while being held down. , is achieved by a method for producing an artificial culture medium for mushrooms, which is characterized by successive cooling. Next, the present invention will be explained in detail based on the drawings. FIG. 1 is an explanatory diagram showing a part of the procedure of an embodiment of the manufacturing process of an artificial culture medium for mushrooms of the present invention, FIG. 2 is an explanatory diagram showing an example of the use of a holding device, and FIG.
The figure is a partially enlarged explanatory view of FIG. 2A, where 21 is a mushroom culture medium and 22 is a culture bag. The method for producing an artificial culture medium for mushrooms of the present invention includes:
For example, do it as follows. First, prepare a transparent culture bag 22 made of polypropylene film,
A mushroom culture medium mixed with sawdust, rice bran, etc. and hydrated is filled into the culture medium bag 22, and the entire shape is adjusted.
At this time, the culture bag used may be appropriately selected from conventionally used storage materials such as plastic film made of polypropylene, etc., and its shape is particularly limited to a cylindrical one with a bottom. For example, the shape may be cylindrical or prismatic with a bottom. Next, as shown in FIG. 1A, the corresponding opening walls 23a, 23 of the culture bag 22 containing the mushroom culture medium 21 are aligned with each other with respect to an arbitrary direction parallel to the opening surface.
1. Overlap and close the parts 2 and 3, and fold the overlapping parts along the mushroom culture surface in the order shown in Figure 1 B and C. At this time, the head space 24 formed by the top surface of the mushroom medium 21 and the culture bag 22 is bent to be as small as possible, so that the gap X between the top surface of the mushroom medium 21 and the culture bag 22 is preferably 5 mm or less. hold it down. If a large head space 24 remains, a large amount of dew condensation will occur on the inner surface of the culture bag 22 after high-pressure steam sterilization, and when it drips off, not only will bacteria enter, but the top surface of the mushroom culture medium 21 will dry out, allowing the seed to be planted. In some cases, poor attachment may occur. Subsequently, several culture bags with their openings bent as described above are arranged on a tray 25 as shown in FIG. 2A, and a pressing device 26 is placed over the culture bags so as to press the bent portions. The tray 25 is sterilized with high pressure steam with the holding device 26 covered, and after completion,
Remove from the sterilization pot while still at a high temperature of about 90℃,
An artificial culture medium for mushrooms can be obtained by cooling the mixture under the condition shown in Figure 2A to 30°C or lower. In the method for producing an artificial culture medium of the present invention, during high-pressure steam sterilization, ventilation is performed by the pressure difference between the atmosphere inside the sterilization pot, the culture bag, and the inside of the mushroom culture medium, and the exhaust and cooling process when the mushroom culture medium is at high temperature after being carried out from the sterilization pot. Ventilation inside and outside the culture bag, such as air intake, is performed through the gap between the walls of the culture bag folded portion 27 shown in FIG. The folded portion 27 is simply made by overlapping and bending the corresponding opening walls of the culture bag 22 based on an arbitrary direction parallel to the opening surface, but the inner surface of the culture bag at the folded portion 27 is completely They are not in close contact and have gaps due to wrinkles in the culture bag 22, unevenness on the surface of the bag material itself, and the like. These various voids communicate the inside and outside of the culture bag 22, allowing air to circulate therein. However, since the above-mentioned voids are minute and not linear, they have an air filtering effect and prevent the invasion of various germs. In addition, the length of the culture bag folded portion 27 should preferably be 20 mm or more, more preferably 50 mm or more, to sufficiently prevent the invasion of bacteria, and adjust the length of the bent portion as appropriate depending on the environment of the cooling room. do it. If the length of the bent part is less than 20 mm, there is a risk of bacteria entering depending on the working environment. The folded part 27 of the culture bag should be further folded at the 28th point (shoulder part of the upper surface of the medium) so that it runs along the mushroom culture medium 21, which is more effective in preventing the invasion of bacteria, but it should be made longer than the height of the mushroom culture medium 21. Folding again at point 29 (bottom part of the medium) prevents evaporation of water adhering to the folded part and the inner surface, and there is a risk that condensation and contaminants may flow into the inside of the mushroom medium 21 when planting the inoculum. The holding device 26 used in the manufacturing method of the present invention is
Use one with a breathable structure. By using such a holding device 26, the culture bag 22
Also, the moisture adhering to the inner surface of the bent portion 27 can be efficiently evaporated, and the invasion of various germs can be prevented. Bacteria cannot grow in dry conditions, but
Mushroom culture medium 21 The spores, etc. that are floating in the air can be easily propagated in the presence of moisture.
The above is extremely important in order to slip into the In addition, the weight of the holding device 26 pressurizes the top surface of the mushroom culture medium 21 to prevent the bent portion 27 from standing up, and furthermore, a head space is formed between the top surface of the mushroom culture medium 21 and the culture bag 22. to prevent it from happening. Here, the weight of the holding device 26 cannot be absolutely defined depending on the material of the containing material, but for example, in the case of a bag made of polypropylene, the weight is preferably 20 g or more per 1 cm ² of the upper surface of the mushroom culture medium 21, and more preferably Set it so that it is 100g or less. If it exceeds 20g, the culture medium will be compressed by the weight of the holding device during proof steam sterilization, and ventilation inside and outside the culture bag will be insufficient, causing the culture bag to rupture.
Or, a vacuum pack-like compression occurs, or
The mushroom medium 21 may become dense, which may adversely affect the growth of mushroom mycelia. Furthermore, by completely covering the holding device 26 as shown in FIG. 2A, deformation of the mushroom culture medium during transportation is prevented. This is particularly effective since the mushroom culture medium is easily deformed at high temperatures when being removed from the sterilization pot after high-pressure steam sterilization. Note that the material of this holding device 26 is not particularly limited, as long as it has heat resistance, such as metal or plastic. In addition, the shape is not limited to a cage-like one with the height of the side plate set lower than the height of the mushroom culture medium as shown in Figure 2A, but also a fishing net-like shape as shown in Figure 2B. , woven fabrics, nonwoven fabrics, twine, porous materials, and other breathable structures may be used alone or in combination of two or more types. Furthermore, the holding device has a second
As shown in Figures A or B, multiple pieces may be covered together, or as shown in Figure C, pressers may be prepared individually. As described above, the artificial culture medium obtained after sterilization and cooling is completed, the opening 23 is opened again in the clean bench, mushroom inoculum such as shiitake, maitake, nameko, etc. is inoculated, and then, as shown in FIG. It can be applied to various culture formats, such as heat-sealing the opening of the culture bag as shown in FIG. 11, or suturing it with thread as shown in FIG. 11, and also enables continuous industrial production. Furthermore, as shown in FIG. 4, compared to case A in which a conventional cap with a filter is used, the present invention B has the following advantages:
Needless to say, since the mushroom seed fungus 30 can be planted over a wide area, the mycelium spreads more quickly and the cultivation period is shortened. The method for producing an artificial culture medium for mushrooms of the present invention includes:
This can be applied to the form of artificial culture medium for all kinds of mushrooms that are cultured in bags. For example, by preparing a cylindrical container 31 with no confinement at the bottom as shown in FIG. 5, and folding it along the mushroom culture medium 32. By providing two portions 33, it becomes possible to plant mushroom seed fungi at multiple points, and it is also possible to significantly shorten the cultivation period of mushroom hyphae. Furthermore, the shape of the artificial culture medium is not particularly limited, such as a cylindrical shape or a rectangular parallelepiped shape. Furthermore, the present invention can be applied to a culture bag 6 equipped with a filter 3 as shown in FIG. It also solves problems. [Effects of the Invention] As described above, the method for producing an artificial culture medium for mushrooms of the present invention involves filling a mushroom culture medium into a containing material made of a film-like material, sterilizing it with high-pressure steam, and cooling it. In the pre-process, the opening walls of the container material are overlapped and bent in any direction parallel to the opening surface, and simply covered with a simple holding device to prevent bacteria from entering the mushroom culture bag. It can be used to sterilize the mushrooms to prevent them from sterilizing, and to produce stable artificial culture for mushrooms due to its appropriate air permeability and shape retention, which prevents the rupture of culture bags, shrinkage of vacuum packs, and the formation of head spaces. does not occur.
In addition, a conventional cap with a filter,
To easily enable continuous industrial production without requiring complicated operations such as fixing the opening of a bag with a rubber ring, a scissor jig, adhesive tape, etc. Moreover, since conventionally used plastic film bags made of polypropylene or the like can be used as is, the cost can be significantly reduced by simplifying the work and reducing the cost of raw materials such as caps with filters. Furthermore, when inoculating the inoculum into the manufactured artificial culture medium, the inoculum can be planted over a wide area.
The mycelium spreads faster and the culture period is shortened. Next, the present invention will be specifically explained with reference to Examples. [Example 1] Cylindrical extrusion molded with a diameter of 12 cm and a thickness
A 50 μm transparent plastic film was cut into a length of 35 cm. Then, the cylindrical film was folded into a gusset so that the folded parts touched at the center, and the bottom was heat-sealed to make a mushroom culture bag made of transparent polypropylene. Next, this mushroom culture bag was filled with 1 kg of mushroom culture medium, which had been mixed with 4 parts by weight of sawdust and 1 part by weight of rice bran to adjust the moisture content to 70%, and formed into a cylinder with a diameter of 12 cm and a height of 14 cm. . Then, the corresponding opening walls of the culture bag are overlapped and brought into close contact with each other with reference to a certain direction parallel to the opening surface, and then folded along the mushroom culture surface, and placed in the tray 34 as shown in FIG. I arranged them. Next, the culture bag was fixed with a presser 35 having an open top and having a large number of ventilation holes in the side and bottom plates so as to press the bent portion of the culture bag. At this time, the weight of the holding device 35 placed on the top surface of the mushroom culture medium was 2 g/cm ² , and the length of the bent portion of the culture bag was 9 cm. Next, these were placed as they were in a high-pressure steam sterilization pot and heated to 121°C.
Sterilized by holding for 90 minutes. After sterilization, temperature inside the sterilization pot
It was taken out at 90°C and cooled until the mushroom medium temperature reached 25°C. Cooling took 12 hours, and the environment inside the cooling room was at a class 100,000 level. [Example 2] The length of the transparent plastic film was 30 cm,
Other than that, filling with mushroom culture medium, bending the opening of the culture bag, attaching a holding device, heating steam sterilization, and cooling were carried out in the same manner as in Example 1. At this time, the length of the folded portion was 4 cm. [Comparative Example 1] The opening of the culture bag was not sealed, but steam sterilization and cooling were carried out with it left open. Note that the other conditions were the same as in Example 1. [Comparative Example 2] The opening of the culture bag was stacked and brought into close contact in the same manner as in Example 1, and then bent along the culture medium surface, but was not pressed with a pressing device. The other conditions were the same as in Example 1. [Comparative Example 3] A non-air permeable plastic sheet was used as the holding device, and the test was carried out under the same conditions as in Example 1 except for that. At this time, the weight applied to the top surface of the mushroom medium was 2 g/cm ² , the same as in Example 1. [Comparative Example 4] Using a commercially available shoulder cap and a cap with a sponge filter, the caps were arranged on a tray as shown in FIG. 7, and heated and steam sterilized and cooled. However, pressing with a pressing device was not performed, and the other conditions were the same as in Example 1. The number of broken culture bags after high-pressure steam sterilization of the artificial culture media of Examples and Comparative Examples produced as described above was investigated, and the top end of the culture bags of the artificial culture media of Examples 1, 2 and Comparative Examples 1, 2, and 3 was investigated. After sealing the cells in a sheet and completely shutting them off from the outside air, they were cultured at 25°C for 10 days, and the number of bacterial contamination was measured. In addition, the artificial culture medium of Comparative Example 4 was cooled and kept as it was for 10 days at 25°C.
After culturing for days, the number of bacterial contamination was measured. Each experiment was conducted using 270 artificial culture media. The results are shown in the table below.

【table】

[Table] From the above results, in Examples 1 and 2, a good artificial culture medium was obtained without breakage of the culture bag or contamination with various bacteria. That is, in Examples 1 and 2, there was no difference in the shape of the artificial culture medium before and after the high-pressure steam sterilization/cooling process. However, in the artificial culture medium of Comparative Example 3, after high-pressure steam sterilization, a large amount of dew condensation was observed on the top surfaces of all the mushroom culture bags, and the culture medium was frequently compressed into vacuum packs. This is thought to be due to water pooling between the plastic sheet and the top of the culture bag during high-pressure steam sterilization, which promoted water condensation on the inner surface of the culture bag's folded part, resulting in poor ventilation inside and outside the culture bag. It was done. In addition, the artificial culture media of Examples 1 and 2 are due to the difference in the length of the folded part of the culture bag, but by adjusting the length of the folded part of the bag according to the difference in the cleanliness of the working environment, It has been shown that bacterial contamination can be completely prevented. Furthermore, the artificial culture media of Examples 1 and 2 were free from bacterial contamination due to fallen bacteria, and the appearance of the artificial culture media was the same as that of Comparative Example 4 using commercially available shoulder caps. That is, according to the present invention, with extremely simple operations, the same germ prevention effect as that obtained using commercially available shoulder caps can be obtained, and after inoculation, the bag opening is sealed with a sheet or sutured with thread, etc. It can be cultured and the manufacturing cost can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of one embodiment of the present invention, FIG. 2 is an explanatory diagram showing an example of the use of the holding device, FIG. 3 is a partially enlarged explanatory diagram of FIG. 2A, and FIG. , an explanatory diagram comparing the conventional method A and the present invention B, FIG. 5 is an explanatory diagram showing another embodiment, FIG. 6 is an explanatory diagram showing the embodiment, FIGS. Figures 9 and 10
11 are explanatory diagrams showing the conventional method. 21...Mushroom medium, 22...Culture bag, 25...
...Tray, 26...pressing device.

Claims (1)

[Claims] 1. When producing an artificial culture medium for mushrooms, after filling a containing material made of a film-like material with a mushroom culture medium, corresponding opening walls of the containing material are overlapped with each other with respect to an arbitrary direction parallel to the opening surface. the overlapping portion is folded along the surface of the mushroom culture medium, the folded portion is held down with a breathable holding device, heat sterilized while being held down, and subsequently cooled. Method for producing artificial culture medium.