What is the difference between selective and differential media quizlet?
What is the difference between selective and differential media quizlet?
What is selective media? Allows the growth of some organisms while inhibiting the growth of others. What is differential media? Differentiates closely related organisms or groups of organisms based on the organism’s biochemical characteristics.
What is a differential media?
Differential media contain compounds that allow groups of microorganisms to be visually distinguished by the appearance of the colony or the surrounding media, usually on the basis of some biochemical difference between the two groups.
Which type of media is both selective and differential?
MacConkey agar is an example of a medium that is both differential and selective. The presence of bile salts, as well as crystal violet, within the media prevent gram-positive organisms from growing.
What is the function of differential media?
Differential media are used to differentiate closely related organisms or groups of organisms. Owing to the presence of certain dyes or chemicals in the media, the organisms will produce characteristic changes or growth patterns that are used for identification or differentiation.
Why is EMB selective and differential?
Eosin Methylene Blue (or EMB) Agar is a Selective & Differential Medium. The selective and differential aspects are due to the dyes Eosin Y and Methylene Blue, and the sugars lactose and sucrose in the medium. It is Selective because it encourages some bacteria to grow while inhibiting others.
Does E coli grow on TSA?
Unheated cells of E. coli O157:H7 grew to population densities of 10(8) to 10(9) CFU ml-1 in TSB (pHs 6.0 and 5.4) at an a(w) of 0.99. coli O157:H7 cells recovered on TSA; pH did not significantly affect the viability of cells.
How do I make TSA media?
Preparation and Method of Use of Tryptic Soy Agar
- Suspend 45 grams in 1000 ml distilled water.
- Heat to boiling to dissolve the medium completely.
- Sterilize by autoclaving at 15lbs pressure (121°C) for 15 minutes.
- Cool to 45-50°C.
- Mix well and pour into sterile Petri plates.
Can fungi grow on TSA plate?
Bacteria are grown on TSA as it is not inhibitive of bacterial growth. It gave the best recovery of bacteria on Cherwell plates and the best recovery of fungi on Oxoid plates. Slightly better results were obtained for fungi on Cherwell plates at 22.5°C and for the recovery of bacteria on Oxoid plates at 32.5°C.
Can salmonella grow on MacConkey Agar?
Result Interpretation on MacConkey Agar Lactose non-fermenting strains, such as Shigella and Salmonella are colourless and transparent and typically do not alter appearance of the medium.