Streptococci are unable to synthesize which enzyme?

Streptococci are unable to synthesize which enzyme?

• A. Catalase
• B. Kinase
• C. Hyaluronidase
• D. Lipase

Answer: (A)

Streptococci are catalase-negative, meaning they do not produce the enzyme catalase that breaks down hydrogen peroxide into water and oxygen. In the lab, a catalase test is used to distinguish these organisms from Staphylococcus, which are catalase-positive and bubble vigorously when hydrogen peroxide is added. The absence of bubbles indicates catalase negativity, a hallmark of streptococci. The other enzymes listed—kinase, hyaluronidase, and lipase—are not universal traits of streptococci and vary among species, so they’re not reliable identifiers for the genus.

Streptococci are catalase-negative, meaning they do not produce the enzyme catalase that breaks down hydrogen peroxide into water and oxygen. In the lab, a catalase test is used to distinguish these organisms from Staphylococcus, which are catalase-positive and bubble vigorously when hydrogen peroxide is added. The absence of bubbles indicates catalase negativity, a hallmark of streptococci. The other enzymes listed—kinase, hyaluronidase, and lipase—are not universal traits of streptococci and vary among species, so they’re not reliable identifiers for the genus.