A simple test to differentiate between Staphylococcus and Streptococcus is the addition of H2O2 to a colony to see if bubbles form, which are positive for catalase. Which organism would be positive

The Correct answer is B, Staphylococcus.

Explanation:

The Catalase test is used to differentiate Staphylococci (Catalase positive) from Streptococci (Catalyst negative). The enzyme catalase is produced by bacteria that respire using oxygen and protects them from the toxic by-products of oxygen metabolism.

Catalase positive bacteria includes strict aerobes as well as facultative anaerobes. Catalase negative bacteria maybe anarobes or facultative anarobes that only ferment and don't respire using oxygen as terminal electron acceptor.

Catalase converts hydrogen peroxide to water and oxygen gas. Though both Staphylococcus and Streptococcus are gram positive bacteria, only Staphylococcus produces catalase enzymes.