What type of culture media contains substances that inhibit some organisms while allowing others to grow?

• A. Enriched media
• B. Minimal media
• C. Differential media
• D. Selective media

Answer: (D)

Selective culture media use inhibitors to suppress some microbes while letting others grow. This lets you isolate or enrich for a specific organism from a mixed sample because only those that tolerate or resist the inhibitors (or utilize the provided nutrients) will form colonies. Enriched media simply add nutrients to support the growth of fastidious organisms without aiming to suppress others. Minimal media provide only essential nutrients and are not designed to inhibit specific groups. Differential media reveal differences between organisms that grow on them but don’t inherently prevent growth of non-target organisms. Some media can be both selective and differential, but the key idea here is the growth-suppressing components that favor certain microbes over others.