Question

Which type of media contains additives like dyes, bile salts, acids, or antibiotics to inhibit the growth of specific bacteria, such as gram-positive ones?

a) Enrichment media
b) Selective media
c) Differential media
d) Enriched media

Answer 1

The media that contain additives to inhibit the growth of specific kinds of bacteria, such as gram-positive ones, are called selective media.

Step-by-step explanation:

The type of media that contains additives like dyes, bile salts, acids, or antibiotics to inhibit the growth of specific bacteria, such as gram-positive ones, is known as selective media. Selective media support the growth of certain microorganisms while suppressing the growth of others.

For instance, MacConkey agar includes bile salts and crystal violet, which inhibit the growth of many gram-positive bacteria, thus promoting the growth of gram-negative bacteria, especially enterics that are adapted to the presence of bile salts. Another example is EMB agar, which contains dyes that inhibit the growth of gram-positive bacteria.