Consider a culture medium on which only gram-positive organi…

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