The EMB (Eosin Methylene Blue) agar is a selective and differential agar medium. It contains sucrose and lactose as fermentable substrates together with Eosin Y and methylene blue dyes which in combination gives the agar its characteristic color when prepared and serves as a pH indicator as well as an inhibitor of growth of Gram-positive bacteria. Hence, it is primarily used to isolate Gram-negative fecal coliforms while some positive fecal coliforms such as Staphylococci are also able to grow.
These coliforms are of two types:
- Lactose or sucrose fermenting coliforms form metallic sheens on the agar as a result of acid production and the response of the indicator to the increased acidity.
- Non-lactose/sucrose fermenters are only able to produce acid by protein deamination. Hence they either form colorless or pinkish colonies on the agar
On the other hand, Mannitol salt agar is a selective and differential agar medium that is primarily used to isolate Staphylococcal bacteria. The presence of sodium chloride in the medium makes it a partial or complete inhibitor of other bacteria.
Hence, an unknown bacterium that forms colorless colonies on EMB will either be a non-lactose fermenting, Gram-negative coliform that will hardly grow on Mannitol salt agar, or a Gram-positive fecal Staphylococcus.
Staphylococci bacteria are of two types:
- Coagulase-positive will form yellow colonies on the Mannitol salt agar.
- Coagulase-negative will form red colonies on the Mannitol salt agar.
More about isolating media can be found here: https://brainly.in/question/7238948
A heart beat, breathing, and moving ;)
In the military strategy of the south the army remains effective, and mobile before an enemy that is stronger to wear it off over time. The plan of the military strategy of the north has three steps: the Union called for the blockade of the south coast, the capture of Richmond, the capture of Mississippi R. With this plan they toppled the south.
Answer:
The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place (Figure below). The transfer of oxygen into the blood is through simple diffusion. ... While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries.
Explanation:
Explanation:
During the first week after menses (in a 28 days cycle), FSH continues to increase, the follicles grow intensely and FSH increases the expression of its own receptor and of the LH receptor on the granulosa cells.
