Catalase Test

A lack of bubbling during the Catalase tests indicated that the organism was Catalase negative.

The enzyme Catalase allows organisms to break down products of oxygen which are toxic. Organisms that tolerate oxygen in the atmosphere will have this enzyme; however, Lactobacillus casei does not have this enzyme because it is microaerophilic. Hydrogen Peroxide, the toxic product, is added to a sample of the organism of interest, L. casei, on a clean slide. If the organism shows bubbling that would mean that the enzyme Catalase is present and therefore the organism could not be Lactobacillus casei.