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Beef Extract is derived from infusion of beef and provides an undefined source of nutrients. Beef Extract is a mixture of peptides and amino acids, nucleotide fractions, organic acids, minerals and some vitamins.
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∙ 12y ago
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∙ 14y agothey are used as food source for bacteria because they contain aminoacid .lipid,protein needed for bacterial growth.
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How do you make pitri dish gel agar?
Agar is generally made by mixing the powdered form with varying ingredients. The powder is based on seaweed extract for nutrient agar, and nutrient agar is generally a base for most other agars - eg. Horse Blood Agar is nutrient agar with horses blood added; Choc agar has defibrinated (cooked) horses blood added.
What purpose does the nutrient agar plate serve?
PREPARATION OF NUTRIENT AGAR Bacteriological media come an a wide range of types. Nutrient Agar is a complex medium because it contains ingredients with contain unknown amounts or types of nutrients. Nutrient Agar contains Beef Extract (0.3%), Peptone (0.5%) and Agar (1.5%) in water. Beef extract is the commercially prepared dehydrated form of autolysed beef and is supplied in the form of a paste. Peptone is casein (milk protein) that has been digested with the enzyme pepsin. Peptone is dehydrated and supplied as a powder. Peptone and Beef Extract contain a mixture of amino acids and peptides. Beef Extract also contains water soluble digest products of all other macromolecules (nucleic acids, fats, polysaccharides) as well as vitamins and trace minerals. Although we know and can define Beef Extract in these terms, each bach can not be chemically defined. There are many media ingredients which are complex: yeast extract, tryptone, and others. The advantage of complex media is that they support the growth of a wide range of microbes. Agar is purified from red algae in which it is an accessory polysaccharide (polygalacturonic acid) of their cell walls. Agar is added to microbiological media only as a solidification agent. Agar for most purposes has no nutrient value. Agar is an excellent solidification agent because it dissolves at near boiling but solidifies at 45oC. Thus, one can prepare molten (liquid) agar at 45oC, mix cells with it, then allow it to solidify thereby trapping living cells. Below 45oC agar is a solid and remains so as the temperature is raised melting only when >95oC is obtained. In this experiment each student will prepare 200 ml of Nutrient Agar to be used in Experiment 4. In subsequent experiments, the media ingredients can be found in the Appendix. It is important for you to know how each medium works: what is the energy source? what is the carbon source? what is the nitrogen source? does the medium have selective or differential ingredients? why can only some types of bacteria grow on the particular medium? MATERIALS 1. Electronic or beam balances. 2. Weigh boats, tongue depressors. 3. Tripods, asbestos wire-gauze, asbestos gloves. 4. 10 ml nonsterile pipettes. 5. pH paper or pH meter with standard buffers. 6. 4 13x100 mm screw capped culture tubes. 7. Graduated Cylinder, 250 ml. 8. 2 500ml Erlenmeyer Flasks 9. Beef Extract, Peptone, Agar. 10. 3 N HCl, 3 N KOH. 11. 16 x 150 mm screw cap culture tubes. 12. Nonabsorbent cotton and gauze to make cotton stoppers. Nutrient Agar Beef Extract: 0.3% Peptone: 0.5% Agar: 1.5% PROCEDURE 1. You will be making 200 ml of Nutrient Agar. To weigh out Beef Extract, first tare a tongue depressor, then dip it into the Beef Extract and weigh. Adjust the amount of Beef Extract until the correct amount is obtained. Be sure to be careful not to get Beef Extract on to the balance! You need to weight out enough Beef Extract to get a 0.3% solution. Place the tongue depressor into the flask, beef extract side down. 2. Tare a weigh boat and weigh out enough Peptone and add that to the flask. 3. Add 200 ml of distilled water and swirl to dissolve the peptone and beef extract. Check the pH, it should be 7.0. 4. Tare a weigh boat and weigh out enough Agar and add that to the flask. 5. With a Bunsen burner, tripod, asbestos wire-gauze, heat the medium to boiling to dissolve the agar. CAREFUL: 1) keep the rotating the flasks to prevent the agar from cooking onto the bottom of the flask and 2) watch out: boiling agar can froth and boil out all over the lab bench. As soon as it begins to boil take it off the heat and put it on to the bench. Allow it to cool a few minutes. 6. While the agar is still warm, but not hot, pipette 3 ml each into 4 13x100 mm screw cap culture tubes. 7. Label the flask and your tubes with your name. 8. After preparation of your medium, the instructor will take you to the autoclave. 9. Place your media in the autoclave with those of the rest of the class. 10. After discussion of the parts of the autoclave, autoclave the medium for 20 minutes. 11. The media will be saved and used in Experiment 4.
If you strongly suspect a nutrient agar slant culture is contaminated what method would you use to ascertain whether you are right or not?
You have to make subculture from this slant and after incubation you can observe how many types of microorganisms are present in the nutrient agar slant. If you have one colony shape so you have a pure nutrient agar slant but if you have more than one type of colonies so the nutrient agar slant is contaminated.
What is the function on bile in Eosin Methylene Blue agar?
To make the Eosin Methylene BLue Agar look cool and hip.
Is it possible to melt a tryptic soy agar slant to make a tryptic soy broth?
No. Agar is a solid at room temperature and would just become solid again. A TSB does not contain agar and therefore can be liquid at room temperature.
How do you make pitri dish gel agar?
Agar is generally made by mixing the powdered form with varying ingredients. The powder is based on seaweed extract for nutrient agar, and nutrient agar is generally a base for most other agars - eg. Horse Blood Agar is nutrient agar with horses blood added; Choc agar has defibrinated (cooked) horses blood added.
What is the purpose of of agar in nutrient agar?
To make it semi-solid
What purpose does the nutrient agar plate serve?
PREPARATION OF NUTRIENT AGAR Bacteriological media come an a wide range of types. Nutrient Agar is a complex medium because it contains ingredients with contain unknown amounts or types of nutrients. Nutrient Agar contains Beef Extract (0.3%), Peptone (0.5%) and Agar (1.5%) in water. Beef extract is the commercially prepared dehydrated form of autolysed beef and is supplied in the form of a paste. Peptone is casein (milk protein) that has been digested with the enzyme pepsin. Peptone is dehydrated and supplied as a powder. Peptone and Beef Extract contain a mixture of amino acids and peptides. Beef Extract also contains water soluble digest products of all other macromolecules (nucleic acids, fats, polysaccharides) as well as vitamins and trace minerals. Although we know and can define Beef Extract in these terms, each bach can not be chemically defined. There are many media ingredients which are complex: yeast extract, tryptone, and others. The advantage of complex media is that they support the growth of a wide range of microbes. Agar is purified from red algae in which it is an accessory polysaccharide (polygalacturonic acid) of their cell walls. Agar is added to microbiological media only as a solidification agent. Agar for most purposes has no nutrient value. Agar is an excellent solidification agent because it dissolves at near boiling but solidifies at 45oC. Thus, one can prepare molten (liquid) agar at 45oC, mix cells with it, then allow it to solidify thereby trapping living cells. Below 45oC agar is a solid and remains so as the temperature is raised melting only when >95oC is obtained. In this experiment each student will prepare 200 ml of Nutrient Agar to be used in Experiment 4. In subsequent experiments, the media ingredients can be found in the Appendix. It is important for you to know how each medium works: what is the energy source? what is the carbon source? what is the nitrogen source? does the medium have selective or differential ingredients? why can only some types of bacteria grow on the particular medium? MATERIALS 1. Electronic or beam balances. 2. Weigh boats, tongue depressors. 3. Tripods, asbestos wire-gauze, asbestos gloves. 4. 10 ml nonsterile pipettes. 5. pH paper or pH meter with standard buffers. 6. 4 13x100 mm screw capped culture tubes. 7. Graduated Cylinder, 250 ml. 8. 2 500ml Erlenmeyer Flasks 9. Beef Extract, Peptone, Agar. 10. 3 N HCl, 3 N KOH. 11. 16 x 150 mm screw cap culture tubes. 12. Nonabsorbent cotton and gauze to make cotton stoppers. Nutrient Agar Beef Extract: 0.3% Peptone: 0.5% Agar: 1.5% PROCEDURE 1. You will be making 200 ml of Nutrient Agar. To weigh out Beef Extract, first tare a tongue depressor, then dip it into the Beef Extract and weigh. Adjust the amount of Beef Extract until the correct amount is obtained. Be sure to be careful not to get Beef Extract on to the balance! You need to weight out enough Beef Extract to get a 0.3% solution. Place the tongue depressor into the flask, beef extract side down. 2. Tare a weigh boat and weigh out enough Peptone and add that to the flask. 3. Add 200 ml of distilled water and swirl to dissolve the peptone and beef extract. Check the pH, it should be 7.0. 4. Tare a weigh boat and weigh out enough Agar and add that to the flask. 5. With a Bunsen burner, tripod, asbestos wire-gauze, heat the medium to boiling to dissolve the agar. CAREFUL: 1) keep the rotating the flasks to prevent the agar from cooking onto the bottom of the flask and 2) watch out: boiling agar can froth and boil out all over the lab bench. As soon as it begins to boil take it off the heat and put it on to the bench. Allow it to cool a few minutes. 6. While the agar is still warm, but not hot, pipette 3 ml each into 4 13x100 mm screw cap culture tubes. 7. Label the flask and your tubes with your name. 8. After preparation of your medium, the instructor will take you to the autoclave. 9. Place your media in the autoclave with those of the rest of the class. 10. After discussion of the parts of the autoclave, autoclave the medium for 20 minutes. 11. The media will be saved and used in Experiment 4.
What is the principle of agar diffusion method?
how to make a well on the agar for pour the extract
If you strongly suspect a nutrient agar slant culture is contaminated what method would you use to ascertain whether you are right or not?
You have to make subculture from this slant and after incubation you can observe how many types of microorganisms are present in the nutrient agar slant. If you have one colony shape so you have a pure nutrient agar slant but if you have more than one type of colonies so the nutrient agar slant is contaminated.
Which group of algae produce agar agar?
Agar comes from Red Algae (primarily the Gracilaria genus).It mainly is produed from the red algae Gracilaria lichenoides.This algae is harvested along the western coast of the United States and in parts of Asia. To extract the agar the Algae is boiled, cooled, purified and then dried. The agar is then make into blocks, flakes, or granules.("Agar agar" is usually abbreviated as "agar".)
What are the uses of beef extract?
To enhance the flavor of beef dishes, and to make stock. It can be added to any dish you want to lend beef flavor to, for example a rice pilaf.
What is the difference between himedia ready to use nutrient agar plate and nutrient agar plates prepared by dehydrated media?
Ready to use plates are more expensive because the main difference between the two is the amount of work you have to do. Already made plates and ready to go. Dehydrated you need to make the agar from scratch and pour into empty petri, and wait for it to solidify before you can use them.
What brands contain Agar?
Agar or agar-agar is gelatin substances that can be obtain from algae. In culinary agar refers to a vegetable gelatin that is being used to make jellies, puddings, and custards products.
Is nutrient agar selective?
By definition, a selective medium is a medium that contains a substance that inhibits the growth of some types of bacteria but doesn't affect the growth of other types of bacteria (this is may be required when you want to isolate a specific type of bacteria from a specimen that contains other types of bacteria). Nutrient agar medium contains the following ingredients: peptone, meat extract, yeast extract, NaCl and agar. Nutrient agar doesn't contain any inhibitory substance for bacteria, therefore, it is not considered selective and instead it is called all-purpose medium. Answer An alternative definition of selective media is a media which allows the growth of some organisms whilst supressing the growth of others. Whilst nutrient agar contains no ingredients designed to supress growth, the composition is not suitable for the growth of certain microbes (fastidious bacteria) and so can be considered selective on this basis. For a case example try Mycobacterium lepraewhich is generally culitaved on living tissue rather than agar media. Nutriet agar is therefore selective in that certain microbes cannot grow on it. However, nutirent agar is generally considered the least selective media avalible. The confusion in answering the question arises in the catagories used to classify media in textbooks. Nutirent agar is suitable for the growth the vast majority of culturable bacteria, (however, it is estimated that only around 5% of the worlds bacteria can be cultured in the lab at present). As nutirent agar is sutiable for the growth of so many bacteria it may be catagorised as an "all purpose" media due to its suitablity for many different applications. However to researchers investigating new areas it is important for "all purpose" not to be confused with "all bacteria" media due to its selectivity. In summary, nutrient agar is selective but is classified "all purpose" as it is designed to allow the growth of many different species.
How do you make unflavored jello without using gelitin?
You can use caragheen (a sea weed extract). Another jelling agent is agar agar. Vegetarians like jelly as well as meat eaters.
What is the function on bile in Eosin Methylene Blue agar?
To make the Eosin Methylene BLue Agar look cool and hip.
