catalase test principle , methods and interpretation

1. Catalase test
Presented by
Dr mohan singh dhakad
Pg resident

2. Catalase Test Overview
• Catalase is an enzyme that catalyzes the breakdown
of detrimental hydrogen peroxide (H2O2) into
oxygen and water.
–H2O2 is a toxic byproduct produced by metabolic
reactions occurring in the presence of water and
oxygen and is toxic to cells
–Thus enzymes, such as catalase, are necessary to
break down H2O2 in microorganisms that live in
environments where oxygen is abundant

3. • The catalase test is used to detect the presence
of catalase in certain bacteria, such as
staphylococci.
• The presences of catalase is indicated by oxygen
bubbles that are produced upon the addition of
hydrogen peroxide, yielding a positive result.
• If no bubbles are present, it is presumed that
catalase is not present (or is not functional).
Examples of bacteria that do not produce
catalase are streptococci.

4. Catalase Test Protocol
Interpretation:
Bubbles will form around
the organism on the loop
if catalase is produced
Procedure:
1. Start with a clean microscope
slide and place a drop of
hydrogen peroxide on it.
2. Using an inoculating loop,
remove some of your assigned
organism and put the loop with
the organism on it into the drop
of hydrogen peroxide. Do not
stir.
3. Observe the drop of hydrogen
peroxide.
Fig. 1 Catalase test on
Staphylococcus aureus.
In this image, H2O2 is
applied directly to
bacterial colonies. The
bottom image
represents a positive
result for catalase.

5. Tube catalase test

6. Positive Catalase Reaction Produced by
Staphylococcus aureus
A positive catalase reaction produced by
Staphylococcus aureus. Using a wooden
applicator stick, a small amount of organism
from a well-isolated 24-hour colony was
collected and placed into the test tube
containing hydrogen peroxide. A positive
result is indicated by bubbling.
American Society For Microbiology ©

7. Summary
The catalase test is used to detect the presence of catalase in certain
bacteria, The presences of catalase is indicated by oxygen bubbles that are
produced upon the addition of hydrogen peroxide, yielding a positive result.
https://microbenotes.com/catalase-test-principle-procedure-and-result-interpretation/

8. Other Example of catalase positive
• Enterobacteriaceae
• Vibrionacae
• pseudomonadacae