Final answer:
b) Staphylococcus aureus. The bacterium that would show immediate bubbling when exposed to 3% hydrogen peroxide due to catalase activity
Step-by-step explanation:
The question asks about which type of bacterium would show immediate bubbling when exposed to 3% hydrogen peroxide (H2O2) due to the production of the enzyme catalase. Catalase converts hydrogen peroxide into water and oxygen gas.
This reaction is important because it helps to protect the bacterial cells from oxidative damage by reducing the buildup of hydrogen peroxide, a potentially harmful byproduct of metabolic processes. The catalase test is used to identify bacteria based on their ability to produce this enzyme.
Among the listed bacteria, Staphylococcus aureus is known to be positive for the catalase test. This means that when a culture of Staphylococcus aureus is mixed with hydrogen peroxide, immediate bubbling can be observed, indicating the presence of catalase that decomposes hydrogen peroxide into water and oxygen (2H2O2 → 2H2O + O2).
On the other hand, Streptococcus pneumoniae does not produce catalase, and thus no bubbling would occur. Escherichia coli and Pseudomonas aeruginosa can produce catalase; however, between the options given, it is Staphylococcus aureus that is the clearest answer based on the context provided about the catalase test.
This indicates the presence of catalase, as this enzyme helps to protect bacterial cells by breaking down hydrogen peroxide into water and oxygen.