FOOD MICROBIOLOGY
MICROORGANISMS IN FOOD
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Mac Conkey agar
|
|
|
Eosin Methylene Blue agar
|
|
|
Blood agar
|
|
|
Mannitol agar
|
Detailed explanation-1: -EMB agar is used in water quality tests to distinguish coliforms and fecal coliforms that signal possible pathogenic microorganism contamination in water samples.
Detailed explanation-2: -On EMB if E. coli is grown it will give a distinctive metallic green sheen (due to the metachromatic properties of the dyes, E. coli movement using flagella, and strong acid end-products of fermentation). Some species of Citrobacter and Enterobacter will also react this way to EMB.
Detailed explanation-3: -Use of eosin methylene blue agar to differentiate Escherichia coli from other gram-negative mastitis pathogens.
Detailed explanation-4: -Eosin dye combines with methylene-blue indicator to produce a color change when lactose or sucrose is fermented. Lactose-fermenting coliforms, such as Escherichia coli, produce blue-black colonies with a green metallic sheen due to the amide bonding of the dyes in an acid condition.