Final answer:
In microbiology, bacteria are divided into two groups based on their ability to lyse red blood cells on agar plates. This helps identify medically important streptococci. Hemolytic streptococci will cause the destruction of red blood cells, resulting in a clearing around the colonies on blood agar.
Step-by-step explanation:
In microbiology, microbiologists divide bacteria into two groups depending on their ability to lyse red blood cells on agar plates. This is done to identify medically important streptococci. They are categorized into Lancefield groups, which correlate to types of hemolysis observed when the bacteria are grown on Blood Agar Plates. For example, Group A streptococci, such as Streptococcus pyogenes, are ß-hemolytic, while the enterococci in Group D are typically non-hemolytic (y-hemolysis).
The presence of hemolytic streptococcus on blood agar will lead to the destruction of red blood cells and a clearing or halo around the colonies. On the other hand, non-hemolytic bacteria like staphylococci will appear as large white colonies without any clearing.