What principles should be followed in the preparation of the medium

1. Choose the right nutrients.

All microorganisms need to contain carbon source, nitrogen source, inorganic salts, growth factors, water and energy for the growth and reproduction of microorganisms, but due to the complex types of microbial nutrition, the nutrient needs of different microorganisms are different, so it is necessary to prepare a highly targeted medium according to the nutritional needs of different microorganisms.

2. The concentration and ratio of nutrients are appropriate.

When the concentration of nutrients in the medium is appropriate, microorganisms can grow well, when the concentration of nutrients is too low, it cannot meet the normal growth needs of microorganisms, and when the concentration is too high, it may inhibit the growth of microorganisms.

3. Control pH conditions.

The pH of the medium must be controlled within a certain range to meet the growth and reproduction of different types of microorganisms or the production of metabolites.

4. Control the redox potential.

Different types of microorganisms have different requirements for redox potential (f), generally aerobic microorganisms can grow normally when the f value is above +, generally +a + is appropriate, anaerobic microorganisms can only grow under the condition of f value lower than +, facultative anaerobic microorganisms carry out aerobic respiration when the f value is above +, and ferment when the f value is below +.

5. The selection of raw materials.

In the preparation of culture medium, we should try to use cheap and easily available raw materials as medium components, especially in the fermentation industry, the amount of culture medium is very large, and the use of low-cost raw materials reflects its economic value.

6. Sterilization treatment.

In order to obtain pure microbial culture, it is necessary to avoid contamination by miscellaneous bacteria, so the equipment used and the workplace are disinfected and sterilized. For the culture medium, it is necessary to carry out strict sterilization. The medium is generally sterilized by autoclave, and the medium is generally used, and the sterilization purpose can be achieved by maintaining it for 15 to 30min under conditions.

1. Choose the right nutrients.

Microorganisms need to grow and reproduce in a medium containing carbon sources, nitrogen sources, inorganic salts, growth factors, water and energy. Different microorganisms have different nutrient requirements. For example, autotrophic microorganisms can synthesize complex organic substances such as sugars, lipids, proteins, nucleic acids, vitamins and other complex organic substances from simple and simple organic substances, so the culture of autotrophic microorganisms can basically be composed of simple inorganic substances.

2. The concentration and ratio of nutrients are appropriate.

When the concentration of nutrients in the medium is appropriate, the microorganisms can grow well, when the nutrients are too low, they cannot meet the needs of microbial growth, and if the concentration is too high, the growth of microorganisms may be inhibited.

3.Control pH conditions.

The pH of the nutrient base must be controlled within a certain range to meet the growth and reproduction of different types of microorganisms or the production of metabolites. In general, bacteria and actinomycetes are suitable for growing in range, and yeasts and molds are usually in range. In order to maintain a relatively constant pH of the medium, a pH buffer is usually added to the medium, and the commonly used buffer is a mixture of monohydrogen and dihydrophosphate.

4.Control of redox potential.

The requirements for the redox potential of the same type of microorganisms are different, and generally aerobic microorganisms can grow normally when the redox potential value is above +, which is generally appropriate in +. Anaerobic microorganisms can only grow below a redox potential value of +.

5. The selection of the principle.

In the configuration of the medium, we should try to use cheap and easily available raw materials as the components of the medium, especially in the fermentation industry, the amount of medium is very large, and the use of low-cost raw materials reflects the economic value.

6. Sterilization treatment.

The medium is generally sterilized by autoclave, and in the process of autoclave sterilization, the long-term high temperature will destroy some temperature-resistant substances. During the preparation of the medium, the presence of foam is not good for the sterilization process, because the air in the foam forms an insulating layer, making it difficult to kill the microorganisms in the foam. Therefore, it is sometimes necessary to add an antifoam agent to the medium to reduce the formation of foam.

It's still a lot.

Principles that should be followed in the preparation of the culture medium.

1. Prepare different media according to the nutritional needs of different microorganisms.

2. Pay attention to the concentration and appropriate ratio of various nutrients to maintain appropriate osmotic pressure.

3. Control the pH of the medium within the appropriate range, so as to facilitate the growth and reproduction of different types of microorganisms or the accumulation of metabolites.

4. The principle of economic saving. Under the premise that the selected medium components can meet the requirements of microbial culture, the most inexpensive and resource-rich materials should be selected as the medium components as far as possible.

5. Control the redox potential. It is especially important for anaerobic microorganisms.

6. The medium should be sterile. Therefore, after the preparation of the medium, the bacteria in the medium should be completely killed.

Choose the right nutrients.

Nutrient concentration and ratio.

pH control.

Control of redox potential.

Selection of raw materials**.

Select the appropriate nutrients, the concentration and ratio of nutrients are appropriate, the pH conditions are controlled, the redox potential is controlled, the selection of raw materials is selected, and the sterilization treatment is carried out.

All microorganisms need to contain carbon source, nitrogen source, inorganic salts, growth factors, water and energy for the growth and reproduction of microorganisms, but due to the complex types of microbial nutrition, the nutrient needs of different microorganisms are different, so it is necessary to prepare a highly targeted medium according to the nutritional needs of different microorganisms.

1.Be careful not to contaminate the medium on the mouth of the tube or bottle when dispensing, so as not to soak the tampon and cause contamination.

Do not overturn your head to avoid ** affecting the concentration of ions in the medium.

3.Stir constantly to prevent the bottom of the agar paste from burning.

4.Prepared in strict accordance with the medium formulation.

1. The purpose is clear: different culture conditions must be used for cultivating different microorganisms; The purpose of cultivation is different, and the selection and proportion of raw materials are different;

2. Nutritional coordination: the investigation or analysis of the constituent elements of microbial cells is the reference basis for the design of the medium, and there is a relatively stable ratio between the various components in the microbial cells. Sakuratomo.

3. Physicochemical suitability: It means that the physical and chemical conditions such as pH value, osmotic pressure, water activity and redox potential of the medium are more suitable.

4. Economic praise and saving: when preparing the medium, we should try to use cheap and easily available raw materials as the components of the medium, especially in the fermentation industry, so as to reduce the production cost.

1. The purpose of Sakura friends is clear: different culture conditions must be used to cultivate different microorganisms; The purpose of cultivation is different, and the selection and proportion of raw materials are different;

3. Physicochemical suitability: It refers to the physical and chemical conditions such as pH value, osmotic pressure, water activity and redox potential of the medium.

4. Economic saving: When preparing the medium, we should try to use cheap and easily available raw materials as the components of the medium, especially in the fermentation industry, so as to reduce the production cost.

According to the needs of different microorganisms, different media are prepared.

Pay attention to the concentration and appropriate ratio of various nutrients to maintain appropriate osmotic pressure.

The pH of the medium is controlled within the appropriate range to facilitate the growth and reproduction of different types of microorganisms or the accumulation of metabolites.

It is necessary to pay attention to the ratio of various raw materials, and the appropriate ratio of each culture medium can be done according to the teacher's requirements.

If you need to heat up, pay attention to the time.

Medium is an artificially formulated nutrient for the growth and maintenance of microorganisms, plant tissues and animal tissues, and generally contains carbohydrates, nitrogenous substances, inorganic salts (including trace elements), vitamins and water.

The principles of configuring the medium are: 1. Select appropriate nutrients: all microorganisms need to contain carbon sources, nitrogen sources, inorganic salts, growth factors, water and energy for the growth and reproduction of microorganisms, but due to the complex types of microbial nutrition, the needs of different microorganisms for nutrients are different.

2. Appropriate nutrient concentration and silver ratio: microorganisms can grow well when the nutrient concentration in the medium is appropriate, and when the nutrient concentration is too low, it cannot meet the normal growth needs of microorganisms, and when the concentration is too high, it may inhibit the growth of microorganisms. 3. Control pH conditions.

The pH of the medium must be controlled within a certain range to meet the growth and reproduction of different types of microorganisms or the production of metabolites. The optimal pH conditions for the growth and reproduction of metabolites vary for each type of organism, but in general, bacteria and actinomycetes are suitable for growth, and yeasts and molds are generally within the range. 4. Control the redox potential.

Different types of microorganisms have different requirements for redox potential (f), and generally aerobic microorganisms can grow normally when the f value is above +, generally +1+0[ ooo