Why is beef paste peptone used in laboratory environment and human surface microbial examination exp

Because beef paste is high in protein.

Why is the microorganism on the surface of the human body different from that of beef paste in the laboratory? What are you talking about? It's not much clear.

Beef paste provides a source of carbon, phosphate, for microorganisms.

and vitamins, peptone mainly provides nitrogen sources and vitamins, and NaCl provides inorganic salts.

Method: Add 100ml of water to a beaker and add beef paste, peptone and sodium chloride.

Mark the outside of the beaker with crayons and heat it over a fire. After the components in the beaker are dissolved, add agar and stir constantly to avoid sticking to the bottom. After the agar is completely dissolved, make up for the water loss, and use 10% hydrochloric acid or 10% sodium hydroxide.

Adjust the pH value.

Then, divide them into individual test tubes, add cotton stoppers, and sterilize with autoclaving: kilograms per square centimeter, 121 degrees Celsius.

Maintain for 15-30 minutes.

Extended Material: Physical Classification of Culture Media.

1. Liquid medium.

80% to 90% is water, which is equipped with soluble or insoluble nutrients.

2. Solid medium.

A class of substrates formulated in a solid state. According to the properties, it is divided into solidification medium, non-reversible solidification medium, natural solid medium, and filter membrane.

3. Semi-solid medium.

Refers to a semi-solid medium prepared by adding a small amount of coagulant to a liquid medium.

4. Dehydration medium.

Also known as prefabricated dry medium, it refers to a commercial medium containing all components except water.

Biology Elective 15 pages: Beef paste provides carbon, nitrogen, phosphate and vitamins; Peptone provides a source of carbon, nitrogen and vitamins. The two answers before He Liang were misleading.

1. A nitrogen source is provided.

2. Both beef paste and peptone contain protein, and protein contains element N.

Beef paste provides carbon sources, phosphates and vitamins for microorganisms, peptones mainly provide nitrogen sources and vitamins, and NaCl provides inorganic salts.

Method: Add 100ml of water to the beaker, add beef paste, peptone and sodium chloride, mark the outside of the beaker with a crayon, and heat it on the fire. After the components in the beaker are dissolved, add agar and stir constantly to avoid sticking to the bottom.

After the agar is completely dissolved, make up for the water loss, adjust the pH value with 10% hydrochloric acid or 10% sodium hydroxide, divide it into each test tube, add cotton stopper, and sterilize it with autoclave: kilograms per square centimeter, 121 degrees Celsius for 15 30 minutes.

Beef paste provides microorganisms with carbon, energy, phosphate and vitamins; Peptones mainly provide a source of nitrogen and vitamins.

1. Beef paste contains creatine, creatinine, peptides, amino acids, nucleotides, organic acids, minerals and vitamins. The product is widely used in biopharmaceutical fermentation and the preparation of various culture media.

2. Peptone is a powder with a light yellow appearance that is dried by hydrolyzing meat, casein or gelatin with acid or protease, and has a special flavor of meat. Peptones can also be formed when proteins are broken down by acids, bases, or proteases. One of the initial products of protein digestion in the stomach is peptone.

Peptones are rich in organic nitrogen compounds and also contain some vitamins and sugars.

The main components of beef paste peptone medium are beef paste, peptone and NaCl, which is a medium widely used for culturing bacteria.

Biology Elective 15 pages: Beef paste provides carbon, nitrogen, phosphate and vitamins; Peptones provide a source of carbon, nitrogen, and vitamins. The previous two answers were wrong.

1. A nitrogen source is provided.

2. Both beef paste and peptone contain protein, and protein contains element N.

Beef paste mainly provides carbon energy, and peptone is a nitrogen source.

Yes. The fungus can be grown on the beef paste peptone medium, and the fungi that generally need to be cultured have low nutritional requirements and grow well on the beef paste peptone medium.

Since you are culturing fungi, you should use the corresponding fungal medium. Beef paste peptone medium is actually mainly used to culture bacteria rather than fungi, and if it is used for culture, it is easy to cause bacterial contamination and seriously affect the effect.

However, the fungal culture medium generally contains components that inhibit the growth of miscellaneous bacteria without affecting the growth of the fungus (such as chloramphenicol), and the fungus can be cultivated at this time. The more commonly used fungal culture media are Bengal red medium, high-salt Chaser's medium, PDA medium, and so on.

Beef paste peptone medium is an ordinary medium, general microorganisms such as bacteria can grow, and microorganisms with urea as a nitrogen source such as urea decomposition bacteria can grow completely, but urea should be added to this medium as the only nitrogen source, and beef paste peptone also contains a nitrogen source, but it can not be used. Personal opinions, criticism and correction are welcome!

Xiaoqiang: Is it possible to think that the macromolecular substances in the medium cannot enter the cells containing the cell wall? I think it's because the microorganisms don't have enzymes that break down this macromolecule.

The chemical nature of most enzymes is proteins, and they are generally macromolecular substances, so how can bacteria with cell walls excrete them out of the cell?

Summary. Dear dear, it's a pleasure to answer your <>

In the process of preparing beef paste peptone medium, the following experimental phenomena may occur:1Due to the inappropriate ratio of raw materials or insufficient temperature during the heating process, the problem of uneven matrix or incomplete solidification will occur.

2.Mutual reactions of various raw material components, such as acid-base reactions, may occur, resulting in precipitates. 3.

Contaminants such as microorganisms may be present in the prepared matrix that can affect the results. 4.At the time of dilution, if the conditions are not strictly controlled, the concentration will change due to the proliferation of microorganisms.

Experimental phenomenon of preparation of beef paste peptone medium.

Dear dear, it's a pleasure to answer your <>

In the process of preparing beef paste peptone medium, the following experimental phenomena may occur: 1Due to the inappropriate ratio of raw materials or insufficient temperature during the heating process, the problem of uneven matrix or incomplete solidification will occur.

2.Mutual reactions of various raw materials may occur, such as acid-base reactions, resulting in precipitates. 3.

Contaminants such as microorganisms may be present in the prepared matrix that can affect the results. 4.In the dilution process, if the control conditions are not strict, the concentration will change due to the proliferation of microorganisms.

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When preparing beef paste peptone medium, it is first necessary to test the formula of ingredients with different proportions to determine the optimal ratio. Then, heat and pressurize in a pressure cooker to add the various ingredients to the beef paste solution to mix. Finally, the matrix is prepared by filtering, sterilization, cooling and other steps.

In the preparation process, it is necessary to master the proportion, heating temperature and time of various components in the cavity resistance, and carry out strict sterilization treatment. At the same time, high-quality raw materials are selected, various aeration, temperature, pressure and other experimental conditions are strictly controlled, and hygiene is paid attention to in the whole process of operation to ensure the quality of the matrix and the reliability of the experimental results. <>

Experimental phenomenon of purification of E. coli by dilution coating plate method.

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Experimental phenomenon of purification of E. coli by dilution coating plate method: 1During the initial coating process, bacteria may accumulate and accumulate on the plate, which may cause some bacteria to fail to grow and form colonies.

2.During the dilution process, there may be uneven bacterial concentrations, resulting in uneven bacterial counts. 3.

During the culture process, there may be changes in the size of different bacterial colonies, which may be due to different growth conditions, competition between different colonies, etc. [Flower Changshi] <>

Beef paste Xiangzhen egg is suitable for culturing () aMold. b.Actinomyces.

c.Bacteria. d.Yeast.

Correct answer: c