Most Bacillus species are Catalase positive.
Care must be taken if testing an organism cultured on a medium containing blood because catalase is present in red cells. If any of the blood agar is removed with the colony, a false positive reaction will occur. It is usually recommended, therefore that catalase testing be performed from a blood-free culture medium such as nutrient agar.
catalase
positive
sugar
Because catalase is found in red blood cells.
The morphologically similar Enterococcus (catalase negative) and Staphylococcus (catalase positive) can be differentiated using the catalase test.
it should test + for catalase but Salmonella isolates are moderate catalase reactors.
Most Bacillus species are Catalase positive.
The main criterion for differentiation between Staphylococcus and Streptococcus genera is the catalase test. Staphylococci are catalase positive whereas Streptococci are Catalase negative. Catalase is an enzyme used by bacteria to induce the reaction of reduction of hydrogen peroxide into water and oxygen.
Care must be taken if testing an organism cultured on a medium containing blood because catalase is present in red cells. If any of the blood agar is removed with the colony, a false positive reaction will occur. It is usually recommended, therefore that catalase testing be performed from a blood-free culture medium such as nutrient agar.
Catalse Test Catalase (also known as peroxidase) is an enzyme that catalyses the breakdown of hydrogen peroxide to oxygen and water. Most higher organisms produce catalase, but in bacteriology this test is usually used to differentiate staphylococci (Catalase positive) from streptococci (Catalase negative). Chemical equation for the breakdown of hydrogen peroxide:2H2O2 → 2H2O + O2 In this test a drop of hydrogen peroxide is emulsified with the bacterial growth, if the organism is catalase positive active bubbling is seen (formation of oxygen) In catalase negative reactions no active bubbling is seen
catalase
positive
hydrogen peroxide
sugar
you need to test both the experiment-organism and an organism which you already know is catalase-positive, in the same environment in order to compare the results and determine if your experiment-organism is catalase-positive. - See more at: http://www.chacha.com/question/why-is-it-advisable-to-perform-a-catalase-test-on-a-known-catalase%26%2345%3Bpositive-organism-along-with-the-organism-you-are-testing#sthash.oChX8ZqW.dpuf