Effervescence produced by Staphylococcus aureus
The catalase test may also use a tube instead of a slide, though the tube is not used
much because it is time and materials consuming.
Inoculate bacterial strain on an agar slant (TSA). Incubate it at 37 °C for a day or two.
Add 1-2 ml of hydrogen peroxide to the tube, look for the presence or absence of
bubbles within a minute. Bubbles mean a positive result.
The superoxol test is analogous to the catalase test, but is performed with a 30%
hydrogen peroxide solution. This reagent is most useful in differentiating between
Neisseria gonorrhoeae (strongly positive), Neisseria cinerea (weakly positive), and
Kingella denitriﬁcans (superoxol negative).
Use culture grown on a blood-free media. Erythrocytes may produce a false-positive
Using a nichrome loop may give a false-positive reaction.
Reaction is more intense when adding on the slide a drop of commercial soap
solution before the hydrogen peroxide.
Some bacteria like Tolumonas auensis give positive results for catalase when growth
aerobically, while anaerobic cultures are catalase-negative.
1. Helgomar Raducanescu, Valeria Bica-Popii,1986. Bacteriologie veterinara, Ed. Ceres, Bucuresti.
2. Tone Tonjum, 2005. Order IV. Neisseriales ord. nov. In: Bergey’s Manual of Systematic Bacteriology, Second edition,Vol two, part C
The Alpha-, Beta-, Delta-, and Epsilonproteobacteria, George M. Garrity (Editor-in-Chief), pp 774-863.
Hydrogen peroxide and oxygen radicals used in bacterial electron transport chains of aerobic and facultative anaerobic respiration are
toxic compounds. Catalase is an enzyme present in most of the organisms and is involved in decomposition of the hydrogen
peroxyde in H2O and O2.
If catalase is present, bubbles will form from the oxygen that is made in the reaction: 2H2O2 + catalase => 2H2O + O2 + catalase.
Because not all bacteria can produce catalase, in bacteriology this test is used together with other tests for bacterial identification.
Prepare a 3% hydrogen peroxide solution and put 1 drop on a slide.
Harvest a well isolated colony and immerse the loop in the solution on the slide.
Observe the quick effervescence for a positive reaction. The absence of bubbling is
considered negative. Record whether bubbles were seen immediately, whether
bubbles were seen with a delay, or if bubbles were not seen within a minute.
As an example, generally Staphylococcus species are catalase-positive and
Streptococcus species are catalase-negative.
(c) Costin Stoica