Final answer:
The area around a microbe without growth when the microbe's growth is inhibited or killed is called the zone of inhibition. This is a critical concept in microbiology, particularly when evaluating the effectiveness of antimicrobial drugs against bacteria.
Step-by-step explanation:
The term for the area around a microbe where growth is inhibited due to the action of an antimicrobial drug is known as the zone of inhibition. This is seen as a clear zone around a filter disk that has been impregnated with the drug, indicating the growth has been stopped or killed due to the drug's antimicrobial properties. In laboratory settings, this is often observed in the disk-diffusion assay where different chemical agents are applied to sterile filter paper disks placed on an agar plate inoculated with bacteria. As the bacteria grow to form a bacterial lawn, any effective antimicrobial will diffuse into the agar and produce a visible clear area around itself, representing the zone of inhibition.
Additional key terms from this explanation include bacteriostatic, which refers to substances that inhibit bacterial growth, and bactericidal, which are agents that kill bacteria. The effective assessment of these properties is crucial in determining the susceptibility of bacteria to antimicrobial agents.