Question

1. Which medium is good for fastidious pathogenic microorganisms such as Helicobacter pylori? Select

only one and explain “why” (your answer must be reasonable)

2. Which medium is good for autotrophs such as Oscillatoria? Select only one and explain “why” (your

answer must be reasonable)

3. Which one is good for selection of only Gram-negative bacteria? Select only one and explain “why”

(your answer must be reasonable)

Answer 1

1. Best medium to grow H. pylori is a Brucella agar with 10% blood. It is motile organisms. Presence of solid surface of agar provides the mechanical support for the growth. Bold provides all the essential nutrients to the bacteria for the growth.

2.
616 medium BG 11

Composition is as follows

3.

MacConkey agar: presence of crystal violet and bile salts inhibits the gram positive bacteria and makes medium selective for only gram negative bacteria.