microbi Is MacConkey agar a defined or an Provide the reason

Is MacConkey agar a defined or an Provide the reasoning behind your choice and explain a why this formulation is In your own words, what are the roles of crystal voter and bile salts in MacConkey agar In your own words, what are the roles of neutral red lactose in MacConkey agar? Think about the results you recorded. Growth on the MacConkey agar NA plates was recorded as \"good growth, -poor growth, or no growth.\" These are qualitative and at least for the first two, subjective terms. What did you use to establish what constituted \"good growth?\" why wouldn\'t it be advisable to compare growth of the organism on each plate to each other There are at least two answers to this question!

Solution

3.macConkey agar is a defined medium of which all the quantities of the components is known and is fixed.This medium is used selectively for gram-negative and lactose fermenting bacteria.

It has peptone a protein digest from animal tissues for nutritional needs, lactose a sugar, crystal violet dye acts both as a dye and an inhibitor of gram-positive bacteria, bile salts, NaCl, neutral red as the indicator of pH.All the above-mentioned components promote the growth of gram-negative and acid-producing bacteria

4.crystal violet has triaryl methane and is usually used as a dye it doesn\'t allow the growth of gram-positive bacteria.Bile salts do not allow the growth of gram-positive bacteria.It is pretty simple bile salts help in degradation or emulsification of fats in the intestines.Now in the case of gram-positive bacteria the outer cell wall composition is lipopolysaccharides and hence they promote the breakdown.

5.Neutral red is used as a pH indicator which turns red when the pH of the solution or medium is below 6.8 and lactose is a carbohydrate which will be used by only the lactose fermenting bacteria and thus promoting their growth than the other organisms.

6.a) Depends upon your practical

b) Any mishandling of the sample during the inoculation and the concentration of the sample inoculum defines the growth quantity.