We can turn the nutrient agar media into an enriched medium by integrating serum and other biological fluids. The formulation of supportive nutrient agar can function as a selective media after incorporating selective agents like antibiotics.
Similarly, if the nutrient agar becomes saturated with specific dyes or chemicals, it will function as a differential media. The composition of nutrient agar media includes the following ingredients per ml of distilled water:.
The composition of nutrient broth is the same as above, but one should skip the addition of solidifying agar. We could easily prepare nutrient broth from the readymade media by taking 13 grams of nutrient broth powder per litre of sterile water. Nutrient agar media supports the culturing and isolation of various non-fastidious bacteria by providing principal sources for their growth. Tryptic Soy Agar - Pseudomonas aeruginosa Note the blue-green color due to pyocin production by the bacteria.
Chocolate Agar. Chocolate Agar - uninoculated. Purpose: Cultivation of fastidious organisms such as Neisseria or Haemophilus sp. Chocolate Agar - Staphylococcus aureus Note: luxuriant growth with yellow pigmented colonies.
Chocolate Agar - Neisseria gonorrhoeae Note: small colonies that appear transparent on close examination. Chocolate Agar - Escherichia coli Note: luxuriant growth of gray-white colonies.
Thayer-Martin Agar. Thayer-Martin Agar - uninoculated. Type: Enriched and selective; contains antibiotics colistin kills gram-negative coliforms , vancomycin kills gram-positives , nystatin kills fungi. Purpose: To select for fastidious organisms, such as N. Thayer-Martin Agar - Staphylococcus aureus Note: vancomycin in the medium inhibits the growth of staphylococci.
Thayer-Martin Agar - Neisseria gonorrhoeae Note: luxuriant growth of this fastidious bacterium. Thayer-Martin Agar - Escherichia coli Note: colistin in the media inhibits the growth of enterics.
MacConkey lactose Agar. MacConkey Agar - uninoculated. Purpose: Contains bile salts and crystal violet which selects for gram-negative enterics, differentiates lactose-fermenters from non-fermenters. It consists of peptone, beef extract, and agar. This relatively simple formulation provides the nutrients necessary for the replication of a large number of non-fastidious microorganisms.
Final pH 6. Composition of nutrient broth: Nutrient broth contains all these ingredients except agar. Nutrient agar and broth are available from most suppliers of culture media in powdered free-flowing, homogeneous form. But i found lots of bacterial contamination in my Nutrient agar culture…. Does the composition of beef extract hampers the groeth of fungus and favours bacteria instead. Hello I have a question. If a leg wound is cultured and it is put on a nutrient agar, Selective agar and Differential Agar what are expected to show?
I streaked out from sweet potato steep water and I had both red colonies and white colonies that turned nutrient agar kind of green.
Please what kind of organisms are these. They areboth staining gram positive. Basal media 2. Enriched media 3. Selective media 4. Enrichment media 5. Differential media. Just list put techniques name so that i could learn it from basics. Could u tell me what are the microbial techniques? Just list out the techniques name so that i could learn it from basics.
Save my name and email in this browser for the next time I comment. Composition of Nutrient Agar 0. Distilled water Water is essential for the growth of and reproduction of micro-organisms and also provides the medium through which various nutrients can be transported.
Preparation of Nutrient Agar 1. Suspend 28 g of nutrient agar powder in 1 litre of distilled water. Heat this mixture while stirring to fully dissolve all components. Autoclave the dissolved mixture at degrees Celsius for 15 minutes. Once the nutrient agar has been autoclaved, allow it to cool but not solidify. Replace the lid of each Petri dish and store the plates in a refrigerator.
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