JP2875608B2 - Method for growing mushrooms with or without sporulation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for growing mushrooms without or with less sporulation. In order to maintain the freshness of mushrooms, it is important to suppress sporulation of fruiting bodies. TECHNICAL FIELD The present invention relates to a method for growing a mushroom having no or little spore formation, and therefore, having good freshness.

<Prior art and its problems> Conventionally, as a method for maintaining the freshness of mushrooms by suppressing spore maturation of fruiting bodies, a method of directly contacting a collected fruiting body with an acidic protease inhibitor has been proposed (see, for example, Japanese Patent Application Laid-Open Publication No. HEI 9-157556). JP-A-62-171640). However, this conventional method has a problem that every time a fruiting body is collected, there is a troublesome work in that an acidic protease inhibitor must be directly contacted with the fruiting body.

<Problems to be Solved by the Invention, Means for Solving the Problems> The present invention is to provide a method for growing mushrooms without or with less spore formation, which solves the conventional problems as described above.

Thus, the present inventors have studied from the above viewpoint, and found that dihydrofolate reductase is closely involved in sporulation of fruiting bodies, and when mushrooms are treated with a dihydrofolate reductase inhibitor, they are formed during the growth of the mushrooms. It has been found that dihydrofolate reductase is directly inhibited, and that the mushroom is inhibited from forming spores. However, the method of treating mushrooms with a dihydrofolate reductase inhibitor has a troublesome work in that the mushrooms must be treated with dihydrofolate reductase each time as in the case of the above-mentioned conventional method.

Then, the present inventors further investigated and found that when the mycelium, spores, basidiospores or protoplasts of mushrooms (hereinafter referred to as mycelia etc.) were treated with a dihydrofolate reductase inhibitor, culture and cultivation were performed using these. And the mushroom obtained by forming the fruiting body is a mutant strain in which part or all of the gene involved in dihydrofolate reductase is mutated, and has no or little sporulation,
Therefore, the characteristics of becoming mushrooms with or without sporulation are genetically fixed, and mushrooms with or without sporulation are extremely good in keeping freshness. Was.

That is, the present invention is based on the concept of treating a mycelium of a mushroom with a dihydrofolate reductase inhibitor.
A method for growing a mushroom having no or little spore formation, comprising treating a mycelium of a mushroom or the like with a dihydrofolate reductase inhibitor, and then culturing and cultivating the mushroom to form a fruiting body. The present invention relates to a method for growing a mushroom having no or little spore formation, wherein a fruit body is formed using a mushroom obtained by the method for growing as a parent strain.

In the present invention, the target mushroom is an edible or medicinal mushroom that forms a fruiting body. This includes, for example, shiitake mushrooms, syrup mushrooms, enokitake mushrooms, oyster mushrooms, shiroshimaji mushrooms, abalone mushrooms, nameko, maitake mushrooms, yamabushitake mushrooms, jellyfish, willow matsutake mushrooms, matsutake mushrooms, mushrooms, and honshimaji mushrooms.

When treating mycelia of mushrooms with a dihydrofolate reductase inhibitor, a solution containing a dihydrofolate reductase inhibitor may be added to the mycelium of mushrooms or the like or a culture thereof, or both may be mixed. It is preferable to inoculate a solid or liquid medium containing a folate reductase inhibitor with a mushroom mycelium or the like or a culture thereof.
Examples of dihydrofolate reductase inhibitors include aminopterin, methotrexate, and trimethoprim, which are usually 30 to 300 μg / g, preferably 50 to 250 μg / g. It is inoculated. When inoculating a culture such as a mycelium of a mushroom, it is also possible to inoculate a culture in which ultraviolet rays are irradiated during the culture to increase the induction of the mutant strain.

In the present invention, after treating a mycelium of a mushroom or the like with a dihydrofolate reductase inhibitor, the mushroom is cultured and cultivated using the same to form a fruiting body, and a mushroom having no or little spore formation is obtained. The regenerated colonies are grown by culturing the mycelium and the like treated with the dihydrofolate reductase inhibitor, and the regenerated colonies are subjected to cultivation.At this time, the regenerated colonies screened by electrophoresis or the like using the dihydrofolate reductase activity as an index are grown. It can also be offered to

Even if the above mushrooms having no or little sporulation are used as a parent strain and a tissue separated from the parent strain is cultivated to form fruiting bodies, a mushroom without or with little sporulation is similarly obtained. The same is true even if the obtained mushrooms are used sequentially. The property of no or low sporulation is genetically fixed. Using the parent strain, when cultivating it to form fruiting bodies, the parent strain can be crossed with other strains, or bred using techniques such as cell fusion or transformation,
The parent strain may be irradiated with ultraviolet rays, treated with a drug, or protoplasted to induce a mutant strain.

The mushrooms thus obtained without or with less sporulation have very good freshness retention. Over a long period of time, the desired quality, such as color and flavor, including form, can be maintained. When such mushrooms without or with less spore formation are subjected to processing, high-quality processed foods, for example, with less coloring of the broth can be obtained.

Hereinafter, examples and the like will be described in order to make the configuration and effects of the present invention more specific, but the present invention is not limited to these examples.

<Examples> Example 1 A mycelium of Pleurotus ostreatus was slant-cultured, suspended in sterile water, and the suspension was filtered to obtain a mycelium fragment solution as a filtrate. Then, while irradiating the mycelium fragment solution with ultraviolet rays (15 W), the mixture was gently stirred for 2 minutes. Separately, prepare a complete plate medium containing aminopterin 200 μg / g,
The complete plate medium was inoculated with a mycelium fragment solution irradiated with ultraviolet rays. This was cultured at 25 ° C. to grow a regenerated colony, and a part of the regenerated colony was cultivated in a bottle to form a fruiting body, and a mutant of Oyster mushroom was obtained.

Table 1 shows the results of a spore print formation test and a freshness retention test of the oyster mushroom parent strain used as a raw material and the oyster mushroom mutant strain obtained here.

The spore print formation test was carried out by placing the fruiting bodies of each strain on filter paper, leaving them at room temperature for one day, and visually observing the spore prints formed on the filter paper. The freshness retention test was performed by leaving each of the collected strains at 15 ° C. or 20 ° C. for 3 days or 5 days and visually observing the form and color tone.

Example 2 Spores separated from willow matsutake were suspended in sterile water,
If the suspension was irradiated with ultraviolet light (15 W), it was gently stirred for 3 minutes. Separately, a complete plate medium containing 200 μg / g of aminopterin was prepared, and the complete plate medium was inoculated with a suspension irradiated with ultraviolet rays. This was cultured at 25 ° C. to grow a regenerated colony, and it was confirmed under a microscope that the regenerated colony was a mononuclear hypha. Then, the regenerated colonies, which are mononuclear hyphae, were crossed with other willow matsutake mushrooms having excellent traits by confrontation culture, and the crossed strain was confirmed under a microscope to be dinuclear hyphae, and the hybrid strain was isolated. Bottle cultivation of the hybrid strain,
Fruiting bodies were formed to obtain a mutant of Salix matsutake.

The results of the spore print formation test and the freshness retention test results of the obtained willow matsutake mutants were almost the same as expected in Table 1 above.

Subsequently, a strain having good growth and freshness was selected from among the above-mentioned willow matsutake mutant strains, and bottle cultivation was performed using the selected strain to form fruiting bodies, thereby obtaining a second-generation willow matsutake mutant strain. The results of the spore print formation test and the freshness retention test of the second-generation willow matsutake mutants obtained here were almost the same as expected in the case of Table 1 above.

The second-generation willow matsutake mutant was filled in a pouch, sealed, and sterilized under pressure and heat with a retort to obtain a processed food.
The processed food obtained here was of high quality with little coloring or turbidity of the broth.

Example 3 Oyster mushroom was protoplasted, and the solution was gently stirred for 3 minutes while irradiating the solution with ultraviolet rays (15 W).
Separately, a complete plate medium containing 150 μg / g of aminopterin was prepared, and the complete plate medium was inoculated with a protoplast solution irradiated with ultraviolet rays. This was cultured at 25 ° C. to proliferate the regenerated colonies, and a portion of the regenerated colonies screened and selected were cultivated in bottles to form fruiting bodies, and oyster mushroom mutants were obtained. The results of the spore pattern formation test and the freshness retention test of the mutant Pleurotus ostreatus obtained here were almost the same as expected in the case of Table 1 above.

<Effects of the Invention> As is clear from the above, the present invention described above has an effect of obtaining a mushroom having a property of no or little spore formation genetically fixed and having good freshness retention.

──────────────────────────────────────────────────続 き Continuing the front page (72) Inventor Tomofumi Yoshida 321-1174 Minami-Akada, Nishinasuno-machi, Nasu-gun, Tochigi Pref. No. 107, Yoshikawa Heights (56) References JP-A-62-171640 (JP, A) Theoretic and Applied Genetics , Vol. 47, No. 4, (1976), p. 155-163 Mycology, Vol. 74, No. 2, (1982), p. 275-279 (58) Fields surveyed (Int. Cl. ⁶ , DB name) A01H 1/00-15/00 A01G 1/04 JICST file (JOIS) BIOSIS (DIALOG)

Claims (2)

(57) [Claims] The present invention relates to a method for sporulation, which comprises treating a mushroom mycelium, a mitosis, a basidiospore or a protoplast with a dihydrofolate reductase inhibitor and then culturing and cultivating the same to form a fruiting body. How to grow mushrooms with little or no mushrooms. 2. Mycelium, spores, basidiospores or protoplasts of a mushroom are treated with a dihydrofolate reductase inhibitor, and then cultured and cultivated using these to form fruiting bodies, thereby producing no or little sporulation. A method for growing a mushroom having no or little spore formation, comprising obtaining a mushroom and then forming a fruiting body using the mushroom as a parent strain.