Question

One way that white blood cells kill bacteria is by using hydrogen peroxide. Based on this information would you expect pathogenic bacteria to be catalase positive or negative? Explain.

Answer 1

catalase is an enzyme which catalyzes the decomposition of hydrogen peroxide i.e. H2O2 in water and oxygen. its main function is to protect the cell from reactive oxygen species because they result in oxidative damage of the cell. its (catalase) presence can be detected in a microbe by adding hydrogen peroxide and the formation of oxygen bubbles. based on the statement "One way that white blood cells kill bacteria is by using hydrogen peroxide", we would expect pathogenic bacteria to be catalse negative because Catalase-positive pathogens make catalase to shut off the radicals of peroxide which makes the pathogens to survive under unfavourable conditions within the host. some examples of catalse-positive microbes are Mycobacterium tuberculosis, Legionella pneumophila, and Campylobacter jejuni.