KR20230108422A - Mushroom seeds culture method using low temperature pasteurization medium - Google Patents

Abstract

The present invention provides a mushroom spawn culture method using a pasteurized medium, characterized in that the mushroom spawn is inoculated and cultured in a pasteurized medium for mushroom spawn culture containing tartaric acid and lactic acid as organic acids and composed of pH 3.0 to pH 4.0 do.

Description

Mushroom seeds culture method using low temperature pasteurization medium}

The present invention relates to a method for culturing mushroom spawn using a pasteurized medium, and more specifically, to culture by controlling the physiological characteristics and bio-conversion system of hyphae by adjusting the medium composition, and heat treatment at low temperature Because it is possible, it relates to a method for culturing mushroom spawn using a new pasteurization medium that can reduce the energy input for medium sterilization.

Mushroom mycelium is rich in amino acids, polysaccharides, proteins, organic acids, vitamins, etc., so it is possible to mass-produce useful substances such as immunity enhancement, antibiotics, and enzymes. Since it is attracting attention as a protein material that can replace , there are many attempts for mass culture.

Methods for mass-producing mushroom mycelium can be divided into solid and liquid culture. Liquid culture is labor and facility intensive, so production costs can be reduced, and when applied to smart factories with IOT technology, certain By maintaining the production conditions, the production volume and quality are uniform.

In general, in liquid culture, carbon sources such as dextrose, maltose, and glucose, complex nitrogen sources such as yeast extract and malt extract, and inorganic substances such as KH ₂ PO ₄ , MgSO ₄ 7H ₂ O are mixed in an appropriate ratio to prepare a liquid medium. The medium used to control the mushroom spawn, production yield and production cost will be different.

The cost required for producing mushroom mycelium is determined according to facilities / instruments such as culture tanks, sterilizers, filtration and recovery machines, and medium compositions, and various research data have been reported to reduce the cost of mycelium culture.

In order to replace expensive media and increase production yield, directly use grains such as soybean meal, wheat, millet, barley rice, brown rice, black beans, and corn as media, manufacture solid media using wheat bran and rice bran extract, solid and A number of research results related to the preparation of liquid medium have been reported. In particular, the production of a medium using potato extract is a medium material that is widely used in the industry.

Excluding facilities, instruments, and media, energy costs for media sterilization also account for a large portion. Solid and liquid media are prepared as sterile media under conditions of high temperature / high pressure (121 ° C, 1.02 atm), and under these treatment conditions, microorganisms as well as spores are completely killed. It is estimated that the input energy cost will account for more than 10% of the total production cost because it is treated for 15-20 min under high temperature/high pressure conditions. Since the liquid medium required for one culture on an industrial scale amounts to several tons, it takes a long time to heat to a high temperature compared to a laboratory scale, and a lot of input costs are incurred. In addition, in order to cool the heated medium to a temperature suitable for culture, additional energy must be input.

Lee et al. (2002) prepared mixed sawdust medium (cotton sawdust, waste cotton, beet pulp) treated with pasteurization (60℃, 12 h), normal pressure pasteurization (100℃, 6 h) and high temperature pasteurization (121℃, 1.3 h). , Cottonseed bark) on mycelial growth was analyzed, and results were reported that the growth density of mycelia and the production of fruiting bodies increased in proportion to the heat treatment temperature of the medium. is believed to be the result of a decrease in

Jeong et al. (2009; 2013) calculated the energy cost by comparing and analyzing the heat transfer rate, heat transfer rate, and time required for sterilization between the sterilization temperature and sterilization time to establish economical sterilization conditions. did About 100,000 kcal is required to sterilize 1,000 kg of liquid medium, and when calculated with the input electricity and oil, about 100 KW of electricity and about 10 L of oil are consumed. Calculating this as an annual (based on 300 days) usage, it is estimated that 30,000 KW of electricity and 3,000 L of oil will be consumed.

The only way to reduce energy is to shorten the heat treatment time by establishing optimal sterilization conditions, but it is practically very difficult to dramatically reduce the technically input energy cost.

(Patent Publication 1) 10-2001-0007639 (2001.02.05)

Therefore, in the present invention, the medium composition is adjusted to control the physiological characteristics of the hyphae and the bio-conversion system, and the culture is performed, and the energy required for medium sterilization can be reduced because heat treatment is possible at a low temperature. It aims to provide a new method for

The technical problem of the present invention as described above is achieved by the following means.

(1) A mushroom spawn culture method using a pasteurized medium, characterized in that the pasteurized medium for mushroom spawn culture containing tartaric acid and lactic acid as organic acids and inoculated and cultured at pH 3.0 to pH 4.0.

As described above, according to the present invention, since heat treatment is possible at a low temperature when culturing mushroom spawn, there is an effect of greatly reducing the energy input for medium sterilization.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims.

In describing the embodiments of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the embodiment of the present invention, which may vary according to the intention or custom of a user or operator. Therefore, the definition should be made based on the contents throughout this specification.

The mushroom spawn culture method using a pasteurized medium according to the present invention includes the step of inoculating and culturing mushroom spawn in a pasteurized medium for mushroom spawn culture composed of tartaric acid and lactic acid as organic acids and having a pH of 3.0 to pH 4.0. .

Hereinafter, the contents of the present invention will be described in more detail.

Mushrooms that can be cultivated in the present invention are not particularly limited, and various edible mushrooms such as shiitake mushrooms, king oyster mushrooms, and oyster mushrooms are sufficient, preferably shiitake mushrooms ( Lentinus edodes ).

The pasteurized medium used in the mushroom spawn culture method using the pasteurized medium according to the present invention contains an organic acid.

Preferably, the organic acid includes at least one organic acid selected from tartaric acid, citric acid, and lactic acid, more preferably a mixed organic acid of two or more kinds, and still more preferably a mixed organic acid of tartaric acid and lactic acid. Preferably, the mixing ratio of tartaric acid and lactic acid is 8:2 to 6:4 by weight, more preferably 8:2.

The medium usable in the present invention is not particularly limited as long as it is a culture medium suitable for the type of mushroom, but preferably YGM medium (yeast = 0.5%, glucose = 2.0%, KH ₂ PO ₄ = 0.05%, MgSO ₄ ·7H ₂ O = 0.05%).

The culture medium for pasteurization according to the present invention is preferably adjusted to pH 3.0-4.0, more preferably pH 3.2-3.8, and most preferably pH 3.4-3.6 by adding the organic acid aqueous solution (eg, 10% aqueous solution). make it regulated.

The pasteurized culture according to the present invention enables sufficient sterilization even at about 60 ° C., and does not hinder the growth of mycelium, so that energy can be greatly reduced during mushroom spawn culture.

Hereinafter, the content of the present invention will be described in more detail with reference to examples, but these examples are only presented to aid understanding of the present invention and should not be construed as limiting the scope of the present invention thereto.

[Example]

(1) Mycelial tissue culture

Shiitake mushroom ( Lentinus edodes ) mycelium used in the experiment was cultured in the following way by separating the tissue from the shiitake mushroom fruiting body. The shiitake mushroom tissue was cut into squares with a thickness of 1 mm and a length of about 3 mm with a sterile surgical scalpel at the thick part where the cap and stem are connected after splitting the mushroom under aseptic conditions. The separated tissue was inoculated into a PDA (potato dextrose agar) medium and incubated at 25°C. When mycelia grew to about 2-3 cm, they were subcultured 2-3 times in a new medium. When the mycelium grew to 70-80% of the Petri dish area, it was used as a spawn for mycelium culture.

(2) Mycelium culture

Mycelium culture was carried out in the following way using a homogenizer after cutting the shiitake mushroom mycelium spawn grown in a petri dish into a square size of 2-3 mm with a surgical scalpel. Each was homogenized for 20 seconds at 6,000-8,000 rpm. As for the homogenized mycelial spawn, strains of 100 um or more were recovered using a nylon fiber filter paper having a pore size of 100 um and inoculated into PDB medium. The air supply was constantly adjusted to 0.15 vvm. Mycelium culture was carried out at 25 ° C. for 5 days and then used as a spawn for subculture.

(3) Preparation of pasteurization medium and evaluation of sterilization effect

Energy-saving pasteurized medium used for medium sterilization was prepared by adding various organic acids to YGM medium (yeast=0.5%, glucose=2.0%, KH ₂ PO ₄ =0.05%, MgSO ₄ 7H ₂ O = 0.05%). . Organic acids used in the preparation of the medium were tartaric acid, citric acid, and lactic acid, and the pH was adjusted to 3.5 and 4.5 using a 10% aqueous solution, respectively. The pasteurization treatment conditions were 0.5, 1, 2, and 5 hours at 60°C. The mixed organic acid was adjusted to a final concentration of 10% aqueous solution by mixing tartaric acid and lactic acid at a ratio of 8:2, 5:5, and 2:8, and the sterilization treatment condition was 60 ° C. for 1 hour.

To evaluate the medium effect of organic acids and sterilization conditions, a dry film (3M Petrifilm Aerobic Count Plates) for measuring general bacteria was used. General bacterial measurement was inoculated with 100 u each of sterilized medium on a dry film medium, and then cultured at 35 ° C for 48 hours.

The culture results are shown in Table 1 (sterilization effect of YGM liquid medium adjusted to pH 3.5 with various organic acids), Table 2 (sterilization effect of YGM liquid medium adjusted to pH 4.5 with various organic acids) and Table 3 (mixed organic acids). It was the same as the sterilization effect of the YGM liquid medium adjusted to pH 3.5) using pH 3.5, and it can be confirmed that the sterilization effect at low temperature is very high when adjusted to pH 3.5. In particular, tartaric acid and lactic acid are mixed at a weight ratio of 8:2 It can be seen that the most effective effect is obtained when mixed organic acids are used.

(3) Evaluation of effects on mycelial subculture and mycelial growth

In order to inoculate a uniform amount of mycelium, the mycelium cultured in the PDB medium was recovered by filtration using 100 um nylon filter paper. After inoculating about 5 mg (moisture content = 95%) of mycelium in YGM medium, it was cultured at 25°C for 5 days. As the control group used in the experiment, YGM medium without organic acids was used, and the pH was 5.56. The air supply was constantly adjusted to 0.15 vvm, and the culture medium volume was 800 ml. The cultured mycelium was recovered by filtration using 100 um nylon filter paper, and as a result of drying, it was confirmed that the mycelium growth was not inhibited, as shown in Table 4 below.

Evaluation of the effect of mixed organic acids on mycelial growth inoculated mycelium amount
(mg, dry basis) Amount of recovered mycelia
(mg, dry basis) control group 0.25 336 pH 3.5 YGM 0.25 325

- Medium composition: mixed organic acid (tartaric acid = 8%, lactic acid = 2%)

-Sterilization conditions: 2 hours at 60℃

The above description is merely an example of the technical idea of the present invention, and various modifications and variations can be made to those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (1)

A mushroom spawn culture method using a pasteurized medium, characterized in that the mushroom spawn is inoculated and cultured in a pasteurized medium for mushroom spawn culture containing tartaric acid and lactic acid as organic acids and composed of pH 3.0 to pH 4.0.