why is it advisable to perform the catalase test on a known

why is it advisable to perform the catalase test on a known catalase- positive organism simultaneously with the organism you are checking?

Solution

The enzyme, Catalase detoxifies and destroys the toxic chemical hydrogen peroxide. In order to find out the bacterium producing catalase, 3% hydrogen peroxide when smeared on the sample of bacteria grown, shows production of gas bubbles. The release of gas bubbles shows the presence of catalase activity. Catalase converts hydrogen peroxide into gaseous oxygen and water. It is advisable to perform the catalase test on a known catalase-positive organism along with unknown organism to assess the hydrogen peroxide has not broken down and to know the hydrogen peroxide activity on the catalase released.