JPH07327663A - Production of soluble agar and agar medium - Google Patents

Abstract

PURPOSE:To provide an agar imparted with cold water solubility and suitable for a medium for culturing microorganisms. CONSTITUTION:This soluble agar is produced by adding agar or agarose to an aqueous solution of a water-soluble polymer such as polyvinyl pyrrolidone, polyvinyl alcohol or polyacrylamide, dissolving the agar or agarose by heating the aqueous solution and removing the water by drying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agar soluble in water at room temperature and a method for producing an agar medium using the agar.

Agar is a major constituent of the cell wall of seaweeds of the Agaricaceae family, and is composed of agarose, a neutral polysaccharide, and agaropectin, an acidic polysaccharide, mixed in a ratio of about 7: 3. , And is widely used in the field of food, but also in the academic field.

That is, agar or purified agarose is used as a medium for culturing microorganisms in biochemistry, and is used as a gel for electrophoresis in the field of electrochemistry.

[0004]

2. Description of the Prior Art A 0.5-1.5% aqueous solution of agar has the property of dissolving at 85 ° C or higher and solidifying and gelling at 30 ° C or lower. Therefore, when making an agar medium for culturing microorganisms in the field of biochemistry, add the nutrients required for agar or agarose, and add water to heat the agar or agarose to dissolve it, and then add it to a petri dish. It had to be transferred, cooled and gelled.

However, when making an agar medium for culturing microorganisms, there are additives that should be avoided from heating. For example, nutrients such as vitamin C having poor heat resistance and antibiotics having poor heat resistance correspond to this, and the latter is used for investigating the resistance of microorganisms in antibiotics.

[0006] Therefore, it is impossible to form an agar medium without applying heat, which has been impossible in the past, and there is no other way but to operate it properly.

[0007]

In the field of biochemistry, agar and agarose are used to prepare a medium for culturing microorganisms, but agar and agarose are dissolved only in hot water, so avoid heating. It is difficult to make an agar medium containing various additives.

Therefore, the development of agar or agarose for a medium that can be dissolved without heating is an issue.

[0009]

[Means for Solving the Problems] The above problems are solved by adding agar to an aqueous solution of a water-soluble polymer such as polyvinylpyrrolidone, polyvinyl alcohol, and polyacrylamide, heating the aqueous solution to dissolve the agar, and then drying. It can be solved by using soluble agar made by removing water.

[0010]

The present invention utilizes the fact that polymers such as polyvinylpyrrolidone, polyvinyl alcohol, and polyacrylamide are water-soluble, and the chain molecule is mixed with the chain molecule of agar or agarose so that both molecules are entangled. This makes agar or agarose soluble in cold water.

That is, when both molecules are put in cold water in a entangled state, the water-soluble polymer dissolves, so that water molecules also penetrate into the agar or agarose molecular chains, resulting in dissolution in water. It will be.

Particularly, since polyvinylpyrrolidone is soluble in alcoholic organic solvents, the present invention can be used to cultivate microorganisms using agar or agarose medium dissolved in alcohol.

[0013]

【Example】

Example 1: (Production Example of Soluble Agar) The following five types of aqueous solutions were prepared by changing the composition ratio. (A) Agar or agarose: 1g Polyvinylpyrrolidone: 1g Water: 2-10ml (b ) Agar or agarose: 1 g Polyvinylpyrrolidone: 0.01 g Water: 1-5 ml (c) Agar or agarose ・ ・ ・ ・ ・ ・ ・ ・ 1g Polyvinylpyrrolidone ・ ・ ・ ・ ・ ・ ・ ・ 0.1g Water ・ ・ ・ ・ ・ ・ ・ ・ 1-5ml (d) Agar Or agarose: 1g Polyvinylpyrrolidone: 10g Water: 10-50 ml (e) Agar or agarose・ ・ ・ ・ ・ ・ ・ ・ 1g Polyvinylpyrrolidone ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 100g Water ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 100 Adjust the amount of water to be added according to the purpose. Here, if the amount of water is small, it becomes a highly viscous solution, which is troublesome to handle. In addition, since the viscosity changes depending on the molecular weight of polyvinylpyrrolidone used, it is necessary to increase the amount of water added when using high-molecular weight polyvinylpyrrolidone.

When this aqueous solution is heated to 90 ° C. or higher, the agar or agarose is dissolved and the solution becomes transparent. Next, this solution was transferred to a freeze-drying flask and freeze-dried by a freeze-dryer to remove water.

The dried product thus obtained is brittle and easy to redissolve, and crushed to obtain soluble agar or agarose. The powder is soluble in cold water and methanol. Soluble in alcohols from to hexanol.

Next, in Examples (a) to (e), soluble agar or agarose can be similarly obtained by using polyvinyl alcohol or polyacrylamide instead of polyvinylpyrrolidone. However, the agar or agarose powder thus produced is not soluble in alcohol. Example 2: (Example of forming agar medium) Materials having the following compositions were used.

Polypeptone: 5 g Yeast extract: 2.5 g Glucose: 1 g Agar:・ ・ ・ ・ 15g Polyvinylpyrrolidone ・ ・ ・ ・ ・ ・ ・ 1.5 to 7g Water ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 1L After heating this solution to dissolve the agar, It was poured into a petri dish to a depth of about 10 mm, and the petri dish was freeze-dried to prepare soluble agar.

Next, when this is used as a medium,
When the amount of water that has been dried and removed is returned to the petri dish, the agar will gel and become an agar medium.If this water is mixed with, for example, antibiotics and vitamins, these substances will be added to the medium. Can be added to.

It is important that the medium is sterilized when it is prepared in this manner. It is freeze-dried and then the petri dish is subjected to gas sterilization or gamma ray sterilization. It can be realized by using a filter-sterilized product.

[0020]

INDUSTRIAL APPLICABILITY According to the present invention, agar or agarose, which is soluble only in hot water, can be dissolved in cold water or alcohol to form a gel, and water is added to the medium for culturing microorganisms. Since it can be used by itself, the labor of preparation can be saved, while it can be stored for a long time because it is in a dry state before use.

Claims (3)

[Claims] 1. Agar is added to an aqueous solution of a water-soluble polymer,
A method for producing soluble agar, which comprises heating the aqueous solution to dissolve the agar, and then drying to remove water. 2. The method for producing soluble agar according to claim 1, wherein the water-soluble polymer is polyvinylpyrrolidone, polyvinyl alcohol or polyacrylamide. 3. An aqueous solution containing agar, necessary additives and a water-soluble polymer is heated to dissolve uniformly, and then the solution is transferred to a petri dish and freeze-dried. A method for producing an agar medium, which comprises gelling by adding a dried amount of water.