Question

Consider a culture medium on which only gram-positive organisms such as Staphylococcus aureus colonies can grow due to an elevated NaCl level. A yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the pH as a result and changing the color of a pH indicator chemical. This type of medium would be referred to as a(n)

Answer 1

A selective and differential medium

Step-by-step explanation:

A Selective and differential medium is utilized in isolating certain micro-organisms. The selective medium permits a certain type of microbe to grow, while inhibiting the growth of others. While, a Differential medium is used to differentiate the close-related organisms.