JPH02104277A - Preparation of culture medium - Google Patents

Abstract

PURPOSE:To efficiently mass-produce a culture medium without deteriorating a culture medium material of low thermal stability by fluidizing the total culture medium material with a small amount of water below a heating limit temperature, then mixing the resultant material with the residual amount of boiling water and dissolving the culture medium material. CONSTITUTION:A culture medium material is dissolved and dispersed in water at a temperature below the heating limit temperature to prepare the first solution in which the above-mentioned culture medium material is converted into a fluid state. The residual amount of water is then boiled to provide the second solution, which is subsequently mixed with the first solution while being stirred. The temperature of the resultant mixture solution is rapidly increased as compared with that in warming or heating the total amount. As a result, deterioration of the culture medium material due to warming or heating can be avoided or suppressed to the minimum. If the dissolution of the culture medium in the mixture solution is insufficient, heating is carried out. The required time, however, can be reduced. The mixture solution, as necessary, is further heated depending on the dissolved state of the culture medium material and the culture medium is simultaneously sterilized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates generally to a method for preparing a culture medium, and in particular to a method for suspending and dissolving culture medium material in a required amount of water, and for dissolving and/or sterilizing the culture medium material. The present invention relates to a method for preparing a medium by heating the medium.

Problems with the prior art The general procedure for preparing a medium is (1) determination of medium composition, (
2) formulation, (3) pH adjustment, (4) dispensing, and (5) sterilization or sterilization. The above steps are subject to change depending on underlying factors.

Media components include various chemicals (reagents), natural nutritional sources (meat extract, peptone, yeast extract, casamino acids, corn starch, soluble plant extract, malt extract, blackstrap molasses), gelling agents (agar, gelatin, etc.), Chelating agents (citric acid, etc.)
etc., and water is generally used as the solvent.

During preparation, each medium component is dissolved in water, but some medium components do not dissolve unless heated, and heating causes deterioration (decomposition of the medium material components).

Includes denaturation, chemical changes, pH fluctuations, coloration, precipitation, etc.

(same below) There is something to do. Furthermore, depending on the formulation of culture medium materials, care must be taken regarding the order of addition. If even one of the medium components is not completely dissolved, the desired medium cannot be obtained. For example, if the gelling agent (agar, gelatin, etc.) is not completely dissolved (so-called lumps occur), it will not solidify to the desired hardness. Also microorganisms to be cultured.

If components that promote or inhibit the growth of animal and plant cells, etc. (hereinafter referred to as microorganisms, etc.) are not completely dissolved, a difference in the concentration of those components in the prepared medium will occur, and the culture results and their judgment will be affect. Heating is generally done in a steamer.

pH adjustment is generally performed after compounding, or may be done before compounding or after heat sterilization or sterilization.

Therefore, in the past, culture media were carefully prepared at the site of use.

However, today, in the fields of medicine, physiology, and biotechnology, opportunities for mass culturing microorganisms and the like have increased. Therefore, at least standard media are manufactured in large quantities by media producers and supplied to consumers.

However, when preparing a small amount of medium, heating for dissolution and heating for sterilization can be performed in a relatively short time, but when heating a large amount of medium, it takes a long time. Prolonged heating causes deterioration of the components, and even if the heating time is shortened by heating at a high temperature, the deterioration is accelerated by partial high-temperature heating. Therefore,
Generally, heating is carried out gradually. Efforts have also been made to keep the rate of temperature rise small at first and then increase it once a certain temperature is reached. In addition, to avoid changes due to heating, it was prepared in small portions. In this case, there was a risk that the culture medium prepared in each steamer would not be homogeneous. In order to solve this problem, it has been practiced to prepare small amounts and then mix and stir them.

In any case, when preparing a large amount of culture medium twice,
It required a long time to prepare.

Means for Solving the Problems The method of the invention presupposes the use of the required amount of water for dissolving the medium material and the use of heat for dissolving and/or sterilizing the medium material.

In the simplest method of the invention, a) the entire amount of medium material is brought to a temperature below its heating limit temperature;

and preparing a first liquid by adding the medium material to as small a amount of water as possible to make it fluid; b) boiling the remaining amount of water to prepare a second liquid; and C) preparing a second liquid. , Mix the first liquid with the liquid under stirring, d) Depending on the dissolution state of the medium material, further heat the mixed liquid if necessary, and if not, immediately dispense it into a culture container, e) Add as necessary. Sterilize the medium as appropriate.

In a further preferred method of the invention, a) the plurality of medium materials used are divided into at least two groups depending on the degree of thermal stability; b) excluding the group of medium materials with the highest thermal stability; The medium materials of each group are dispersed in as little water as possible, sufficient to make the total amount of each fluid in a fluid state at a temperature below the respective heating limit temperature, so that the medium materials have relatively low thermal stability. C) Adding the group of the most thermally stable medium materials to the remaining amount of water and heating to the heating limit temperature of the medium materials contained to prepare the second liquid. prepared, C)
Mixing the above-mentioned two or more first liquids with the second liquid while stirring,
d) Depending on the molten state of the medium material, heat the mixture further if necessary, otherwise dispense it immediately into culture vessels, e
) If necessary, sterilize the medium.

More preferably, the medium component contained in the second liquid is a component that is stable at boiling temperature, and the second liquid is heated to boiling temperature.

The ratio of the amount of water used to prepare the first solution to the remaining amount of water used for the second solution varies depending on the medium material used, but when using agar as a gelling agent, the ratio is 2:
The ratio may be 8 to 5:5.

Effect: According to the method of the present invention, a large amount of the second liquid is heated to a relatively high temperature, preferably boiling temperature, and a small amount of the first liquid is heated to water below the heating limit temperature (preferably below the heating limit temperature). The temperature of the mixed liquid can be raised rapidly compared to the case where the entire amount is heated or heated. Deterioration of the medium material can be avoided or minimized.

If the medium material in the mixture is insufficiently melted, further heating is required, but the required time can be shortened, thus avoiding or minimizing deterioration of the medium material due to the additional heating. be able to.

Thus, the total time to prepare the same amount of medium can be significantly reduced.

Examples Example 1 The total amount of the following culture medium materials was mixed with 1OOQ of water (a degree 2]'O
) to prepare a first solution.

Boil 40Q of water (15°C) (100°C) and
A liquid was prepared.

While stirring the second liquid, the first liquid was mixed to obtain a mixed liquid of 8010C. When the resulting mixture was further heated to 93°C and maintained at that temperature for 10 minutes, the medium material was completely dissolved. The total time required was 35 minutes.

Composition of medium materials A, Meat extract 200g B, Peptone 500g C0 Lactose 500g D, Agar powder 750g In addition, in the above materials, meat juice and enzymes can withstand high temperatures to a certain extent, but slight changes in organic substances such as amino acids I can't escape it. Lactose is sensitive to heat and turns yellow when heated for a long time at <100°C. In addition, agar powder has some heat resistance, but its gel strength decreases when heated for a long time.

Example 2 A first solution having the following composition was prepared.

Part 1 Liquid C1 lactose 500g D. Agar powder 750g Water OQ Second liquid A. Meat extract 200g B. Peptone 500g Water (15℃) 40Q Prepare the first liquid by stirring and dissolving the ingredients for the first liquid.

The materials for the second liquid were mixed and heated to 93°C to prepare the second liquid.

While stirring the second liquid, add the first liquid and further raise the temperature to 1.
It was maintained for 0 minutes. The medium was completely dissolved.

The total time required was 35 minutes Comparative Example A medium material with the same composition as in Example 1 was mixed with the entire amount of water (temperature 15
The mixture was dissolved and dispersed at 93° C., and the temperature was slowly raised to 93° C., and the temperature was maintained for 10 minutes.

The time required was 60 minutes.

No change was observed in the performance of the culture media obtained in Examples 1 and 2. The medium obtained in the comparative example had a very slight yellowing, and the pH was slightly shifted to the acidic side.

Regarding yellowing, although the effect on culture medium performance is unknown, it was enough to cause problems in commercial value. Further, subtle changes in pH may require correction depending on the purpose.

Effect of the invention The effects of the method of the present invention are as follows.

(1) A medium containing a medium material with low thermal stability can be produced in large quantities without deteriorating the medium material.

(2) A large amount of culture medium can be produced efficiently.

De Junjin Elmenx Co., Ltd.

Claims (1)

[Scope of Claims] [1] A method for preparing a medium in which a medium material is dissolved in a required amount of water and heated for dissolving and/or sterilizing the medium material, comprising: a) heating the entire amount of the medium material; Prepare a first liquid by adding it to as small a volume of water as possible that is at a temperature below the critical temperature and that is sufficient to bring the medium material into a fluid state; b) Boil the remaining amount of water to prepare a second liquid. c) mixing the first liquid with the second liquid under stirring; d) depending on the dissolution state of the medium materials, further heating the mixture if necessary, otherwise immediately placing it in the culture vessel. A method for preparing a medium, comprising: dispensing the medium; e) sterilizing the medium, if necessary. [2] In a culture medium preparation method in which culture medium materials are dissolved in a required amount of water and heated for dissolution and/or sterilization of the culture medium materials, a) the plurality of culture medium materials used are heated to a degree of thermal stability; b) excluding the group of medium materials with the highest thermal stability, the medium materials of each group are flowed at a temperature below the respective heating limit temperature and the total amount of each group is c) prepare one or more first liquids of relatively low thermal stability by dispersing them in as small a volume of water as possible to obtain the conditions; c) the remaining amount of the most thermally stable medium material; c) mixing the one or more first liquids with the second liquid under stirring; d) Depending on the state of dissolution of the medium material, if necessary, the mixture is further heated, otherwise it is immediately dispensed into culture vessels; e) If necessary, the medium is sterilized. How to adjust the culture medium. [3] The method according to claim 2, characterized in that: a) the medium component contained in the second liquid is a component stable at boiling temperature, and the second liquid is heated to boiling temperature. How to prepare the culture medium.