Question

What does a positive result of a bacterial "catalase" test look like? What's in it that makes it look like so? Select one: O a. The small clump of bacteria appear at the bottom of the tube of test broth. The color of the broth turns deep red, showing acidic substance is being secreted by the bacteria b. The small clump of bacteria makes bubbles/ foams, and it is oxygen gas that's in the bubbles O c. The agar turns to a liquid, showing the exoenzyme catalase is being released d. The small clump of bacteria turns deep blue/ purple in color, because the bacterial catalase enzyme turns the test reagents to deep blue/ purple color

Answer 1

Option B - The small clump of bacteria makes bubbles or foams and it is oxygen gas thats in the bubbles

While testing the bacteria for catalase, hydrogen peroxide is added to them and the hydrogen peroxide is substrate for the enzyme catalase which convert hydrogen peroxide into water and oxygen. By the release or presence of bubbles it is confirmed that oxygen is released by the catalase action and defined as ccatalase positive.