JPH0471421A - Production of solid sterile culture medium - Google Patents

Abstract

PURPOSE:To obtain the title culture medium useful for mushroom culture, having excellent productivity by sterilizing a waste treatment material or deactivating an enzyme therein by using an extruder for a raw material containing the waste treatment material to give a sterile culture medium, and packing the sterile culture medium into an aseptic chamber. CONSTITUTION:For example, a raw material containing a waste treatment material such as sawdust or rice bran is passed through an extruder (preferably 140-160 deg.C barrel temperature and 20-60kgf/cm<2> inner pressure), and sterilization of the waste treatment material or deactivation of enzyme therein is continuously carried out to give a sterile culture medium and the sterile culture medium is packed preferably at 60-100 deg.C into a device having a delivery part at the side of an aseptic chamber sterilely connected to the die part.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a method for producing a solid sterile culture medium used for culturing mushroom cultivation, young plant seedlings, etc. using an extruder. Our objective is to provide a continuous production system that performs sterilization, enzyme deactivation, etc., and molds and fills the obtained bacterial culture medium.

[Conventional technology] The demand for mushroom cultivation such as shiitake mushrooms, shimeji mushrooms, and enokitake mushrooms has increased significantly due to the recent natural food boom, and the amount of mushroom production using not only log cultivation methods but also artificial cultivation methods has increased. .

Additionally, with the development of biotechnology, the demand for solid sterile culture media has increased in the field of plant tissue/cell culture breeding.

In the production of solid sterile culture media, it is essential to sterilize and deactivate enzymes, since microorganisms are mixed in the treated material. For this reason, the fatigue treated body (medium composition) is filled into a predetermined I container, and after compression molding, high pressure El rj # * W 4m
Input 121℃N degree f) >1411te, 30~
A method of sterilizing a fatigued body using heated steam for about 180 minutes or placing it in a normal pressure y1s * W1 < steamer type normal pressure sterilizer) 9
A method is used in which the fatigue-treated body is sterilized using heated steam at a temperature of about 6° C. for about 4 to 10 hours.

For example, JP-A-62-210921, JP-A-2-1
Two companies have published sterilization methods, such as in Publication No. 04262.

Other sterilization and enzyme deactivation methods that involve solid matter in the fatigued body include fluidized bed continuous M sterilizer, powder sterilizer, gas sterilizer, high frequency sterilizer, hydrolock continuous sterilizer, and radiation sterilizer. Methods such as the killing method are known.

[Problem S to be solved by the invention] Since the raw material containing the treated body is contaminated with many microorganisms, it is difficult to use it as it is as a culture medium for artificial mushroom cultivation mounds or juvenile plant tissue culture. Therefore, a considerable amount of time and energy is spent on sterilization and the like.

High-temperature/high-pressure gil equipment (hereinafter referred to as autoflave), atmospheric pressure sterilization equipment, etc. are used for sterilization, enzyme deactivation, and other treatments. Since the autoflave is a pressure-tight container, it has drawbacks such as a large device and high packaging costs.

Normal j1 - The sterilizing device (steamer type normal pressure i-bacterial device) may not come into contact with heated steam depending on the shape of the sterilized body or the size of the filling material, or the location of the sterilized body in the atmospheric sterilizer. I also appreciate things that aren't done enough. For this reason, complete sterilization requires a longer heating time, which has the disadvantage of increasing energy costs. Furthermore, during the sterilization process, the atmospheric sterilizer must be constantly monitored for safety and other reasons.

In the gas sterilization method and the radiation &ll sterilization method, gas may remain depending on the fatigue-treated body, and the fatigue-treated body is susceptible to TRT damage due to radiation, and it is difficult to handle numerically.

There is a need for the development of an inexpensive sterilizer that can easily sterilize exhausted bodies and deactivate enzymes, has high productivity, and is easy to handle.

[jli! The present inventor uses an extruder on the raw material containing the fatigue-treated body to continuously inactivate the bacteria or enzymes of the fatigue-treated body (to obtain a culture medium without any This is a method for producing a solid fiiM culture medium, which consists of a first step and a second step of filling a ji idle culture medium.

The purpose of the present invention is to provide a device that can obtain high sterilization efficiency by providing a heating function to the screw part of an extruder in order to sterilize fatigued bodies with low thermal conductivity or to increase the efficiency of deactivating enzymes.

In addition, in order to obtain a solid sterile culture medium that is completely sterilized during the filling process, by providing an ejection part of the die part of the extruder on the sterile room side, microorganisms originating from the exhausted body can be removed even during long-term culture. The purpose is to provide a solid intact culture medium in which no growth is observed.

Hereinafter, the present invention will be described in detail regarding the sterilization mechanism of the exhausted body, the extruder, the filling of the sterile culture medium, etc.

As methods for sterilizing microorganisms, heating, freezing, high frequency, ultrahigh pressure, N agent, ultrasonic waves, etc. are used.

Microorganism killing I11 machine side 1wL varies depending on the type of organism and sterilization method.

For example, sterilization by heating and pressure increases the lag time of microbial growth, leaks intracellular substances, and reduces enzyme activity. It is known that microorganisms are killed by changes in the intermolecular forces of proteins, which are biopolymers (phase 1i), by the mechanism that degrades in-utero nNA, etc.

When sterilizing with Auto 7 Rave, there is a correlation between the vapor pressure and temperature of the water, but with an extruder, there is no correlation between IF, force and temperature. Optionally depending on the composition of the fatigue treated body, etc.: A! ! It is possible to do so.

Even though the temperature is the same as that of autoflakes, the pressure applied to Extro-Goo is one to several hundred times higher, which enhances the conditions for killing microorganisms and improves the killing efficiency.

One eyelid, the fatigue place of the present invention J9! Materials include wood raw materials such as sawdust, wood chips, chip dust, and crushed wood products generated during wood processing, grain meal such as rice bran, rice husks, rice straw, soybean meal, oil cake, and others.

Examples include vitamins, minerals, and cytokinins. They can be used alone or in combination of two or more. The blending ratio varies depending on the type of culturing and is not particularly limited.

Raw materials containing fatigue-treated bodies can be subjected to pretreatment such as mixing, kneading, and heat treatment. When blending a small amount of raw materials, it is preferable to pre-treat them.

Extruder The extruder of the present invention is classified into single-shaft, double-shaft, and multi-shaft types depending on the number of screw axes9. A single-screw extruder is desirable from the viewpoint of practicality such as performance.

Two-shaft and multi-shaft extruders are expensive,
Handling is complicated, running costs are high,
The cleaning workability after use is more complicated than that of the single-screw type, and the screws and other consumable parts are expensive, making them unsuitable.

The extruder of the present invention is driven by a motor while controlling the barrel temperature with a heating device.
This device has functions such as cross-wiring and 16N crushing, and performs extrusion molding and filling from the goose part. Furthermore, a heating temperature control is attached to the screw part, and the goo part and filling 'A' position are sterile! ! This is a device connected to the bacteria room.

For example, good operating conditions for the extruder in the first and second steps vary depending on the type of fatigued body and the solid sterile culture medium, but the barrel temperature is 120 to 18
At 0°C, preferably 140-160°C, the pressure inside the barrel is 1-90 kg (/d, preferably 20-60 ktr
/d.

If the barrel temperature is less than 120°C, the sterilization and enzyme deactivation effects will be reduced, which is not good; if the barrel temperature exceeds 180°C, the components of the irradiated product will be overly decomposed, which is not good.

If the pressure inside the barrel is less than 1 kf/-, sterilization and enzyme deactivation will not be carried out sufficiently, which is not good; if the pressure inside the barrel exceeds 90 hr/-, the heating will cause excessive decomposition of the components of the irradiated body. This is undesirable in that it reduces filling work efficiency and increases equipment costs.

Next, the reasons for the limitations of the present invention will be described.

If the temperature of the fatigued object is low, the thermal conductivity is poor, or if you are processing a somewhat large fatigued object, it will take time for the barrel to reach the set temperature, making it difficult to obtain a sufficient sterilizing effect. Heating by the barrel alone is not good because sufficient heat may not be transferred through contact between the screw and the fatigue treated body, which may cause a reduction in the effectiveness of G1 bacteria, etc.

As a method to improve this cause, it was possible to reduce the temperature distribution of the fatigue-treated body inside the barrel by imparting a heating capacity of 81 to the screw shaft. The heating v1 function is that the structure is such that an electric heater or heat medium can be passed through the center of the screw shaft. The temperature is equivalent to the barrel temperature to l
The temperature is about 0°C higher, and by attaching a bottle, etc. to the screw to further improve the temperature distribution inside the barrel, the temperature distribution of the fatigued body inside the barrel can be made even more uniform to enhance the stirring action. is now possible.

During the forming and filling operations in step 2-1, remove part of the goo part or barrel! ! By aseptically connecting the discharge section to the bacterial chamber side, molding and filling operations can be carried out without an 11i-shape.

The entire extruder! ! If it is installed in a bacteria room, the treated body will be contaminated with microorganisms, so it will be solid! !
It is not good because the shade can cause contamination even to the threshold culture medium.

In addition, installing the extruder in the -i's 12th room (normal room) makes it difficult to keep the filling device attached to the goo sterile, making the device larger and more complicated to handle. This is not desirable in that it becomes

悉-Direct jjL! Shiiji j The sterile culture medium obtained in the first step is transported to the guid part and used by the molding and filling equipment attached to the tip of the die! ! Filled with bacteria into containers and bags.

To obtain a shaped solid sterile culture medium, culture 1
Depending on the type and size, the hardness of the F4 material can be adjusted arbitrarily by applying pressure at the tip of the goo. It is not possible to limit the die tip pressure.

The solid i*ta* base powder production method can be carried out by attaching a device for filling a container to the tip of a goo. If the pressure at the goo tip is high, a resistor tank etc. can be used.

The temperature of the filling device is preferably 60 to ioo°C in consideration of workability, safety, and the like.

] In the present invention, ultrasonic waves, microwaves, pulsed discharge, etc. can also be used in combination.

The present invention will be explained in more detail below using Examples.

[Example] Examples 1-G Crushed oak wood] 00 parts, rice bran 20 parts.

The water content of the fatigue-treated body containing 15 parts of wheat bran and water is the highest.
The amount of water was adjusted to the values shown in the table, and the samples were left outdoors for one week. The microbial culture N groups obtained by sterilizing and deactivating enzymes under the operating conditions shown in Table 1 using a device in which this fatigued body was passed through a heating medium through the screw shaft of an extruder was attached to the tip of a gooey. It is transported to a mold and solidified by compression molding! ! A bacterial culture medium was obtained. The gooey part and the compression molding device were connected to a sterile room to produce a solid sterile culture medium.

() The solid sterile medium was incubated at 37°C on Sabouraud agar medium, which is a fungal confirmation medium, 1 hour and 21 days after production.
60 hours on potato dextrose agar medium at 30℃, 7
Culture was performed for 1 day. Using 10 petri dishes for 1 specimen, the steel saving property was evaluated by the number of plates in which colonies were generated.

Deactivation of the enzyme (cellulase activity) was determined by dispersing 10 g of solid sterile culture medium in 50 ml of sterile water, pulverizing it with a homomixer, separating it using M81 at the same speed, and dispersing the supernatant liquid 5.
m! , filter paper No., 51. Place two pieces of lil
After shaking for 1 hour at a temperature of 40° C., the disintegration state of the filter paper was visually determined.

The state of extrusion at the tip of the goo was visually determined.

Examples below, ratio @! Bactericidal properties shown in examples. Cellulase activity and extrudability tests were also evaluated in a similar manner.

[Comparative Example] Comparative Example 1.2 A fatigued body treated in the same manner as in Example 1 was placed in an extruder to obtain a solid sterile culture medium under the conditions shown in Table 1.

Comparative Example 3 A solid culture medium obtained by compression molding a fatigued body treated in the same manner as in Example 1 was placed in a polyethylene bag and heated at 96°C under normal pressure for 7 hours! 111i was performed to obtain a solid sterile culture medium.

Comparative Example 4 A solid culture medium obtained by compression molding a fatigued body treated in the same manner as in Example 1 was placed in a polyethylene bag at 121°C, 9
Pressure sterilization was performed for 0 minutes to obtain a solid sterile culture medium.

[Effects of the Invention] By carrying out the present invention, all of the above [1] can be achieved.

In other words, Ex I Ruder's? By effectively utilizing functions such as temperature, high pressure, kneading, and moldability, solid p! , it is possible to provide a system in which LII culture medium can be continuously and efficiently sterilized in a small-scale facility using inexpensive equipment.

Claims (3)

[Claims] (1) A first step of obtaining a sterile culture medium by continuously sterilizing the processed material or inactivating the enzyme using an extruder for the raw material containing the processed material, and a second step of filling the material with the sterile culture medium. A method for producing a solid sterile culture medium characterized by: (2) The method for producing a solid sterile culture medium according to claims 1 and 2, characterized in that in the first step, the screw portion of the extruder is heated. (3) The method for producing a solid sterile culture medium according to any one of claims 1 to 3, characterized in that in the second step, the die part is connected to a delivery part on the sterile room side.