Catalase is an enzyme, which is produced by microorganisms that live in oxygenated environments to neutralize toxic forms of oxygen metabolites; H2O2. The catalase enzyme neutralizes the bactericidal effects of hydrogen peroxide and protects them. Anaerobes generally lack the catalase enzyme.
Catalase mediates the breakdown of hydrogen peroxide H2O2 into oxygen and water. To find out if a particular bacterial isolate is able to produce catalase enzyme, a small inoculum of bacterial isolate is mixed into hydrogen peroxide solution (3%) and is observed for the rapid elaboration of oxygen bubbles. The lack of catalase is evident by a lack of or weak bubble production.
Catalase-positive bacteria include strict aerobes as well as facultative anaerobes. They all have the ability to respire using oxygen as a terminal electron acceptor.
Also, read: Oxygen requirements of Pathogenic bacteria
Catalase-negative bacteria may be anaerobes, or they may be facultative anaerobes that only ferment and do not respire using oxygen as a terminal electron acceptor (ie. Streptococci).
Percentage of H2O2 used on catalase test:
- For routine testing of aerobes, 3% hydrogen peroxide is used.
- 15% H2O2 solution: for the identification of anaerobic bacteria
Catalase test is used to differentiate aerotolerant strains of Clostridium (catalase negative) from Bacillus species (catalase positive). - The superoxol catalase test used for the presumptive speciation of certain Neisseria organisms requires a different concentration of H2O2.
Uses of Catalase Test Results
- The catalase test is primarily used to distinguish among Gram-positive cocci: members of the genus Staphylococcus are catalase-positive, and members of the genera Streptococcus and Enterococcus are catalase-negative.
- Catalase test is used to differentiate aerotolerant strains of Clostridium, which are catalase negative, from Bacillus species, which are positive.
- Semiquantitative catalase test is used for the identification of Mycobacterium tuberculosis.
- Catalase test can be used as an aid to the identification of Enterobacteriaceae. Members of Enterobacteriaceae family are catalase positive.
Quality control:
The hydrogen peroxide reagent must be tested with positive and negative control organisms each day or immediately before unknown bacteria are tested.
A. Positive control: Staphylococcus aureus
B. Negative control: Streptococcus species
Procedure of Catalase test (Slide Test)
- Transfer a small amount of bacterial colony to a surface of clean, dry glass slide using a loop or sterile wooden stick
- Place a drop of 3% H2O2 on to the slide and mix.
- A positive result is the rapid evolution of oxygen (within 5-10 sec.) as evidenced by bubbling.
- A negative result is no bubbles or only a few scattered bubbles.
- Dispose of your slide in the biohazard glass disposal container.
Tube Catalase Test-Procedure and Results
- Add 4 to 5 drops of 3% H2O2 to in a test tube
- Using a wooden applicator stick, collect a small amount of organism from a well-isolated 18- to 24-hour colony and place into the test tube (Note: Be careful not to pick up any agar (esp if using Blood Agar).- Explanation in precaution below)
- Place the tube against a dark background and observe for immediate bubble formation (O2 + water = bubbles) at the end of the wooden applicator stick.
Catalase Positive and Catalase Negative Reactions
Results:
- Catalase Positive reactions: Evident by immediate effervescence (bubble formation)
- Catalase Negative reaction: No bubble formation (no catalase enzyme to hydrolyze the hydrogen peroxide)
You can perform Catalase Test online here
Precautions while performing catalase test
- Do not use a metal loop or needle with H2O2; it will give a false positive and degrade the metal.
- If using colonies from a blood agar plate, be very careful not to scrape up any of the blood agar as blood cells are catalase positive and any contaminating agar (carryover of red blood cells) could give a false positive.
- Because some bacteria possess enzymes other than catalase that can decompose hydrogen peroxide, a few tiny bubbles forming after 20 to 30 seconds is not considered as a positive test.
I am impressed and I learned a lot
how to differentiate between staphylococcus and streptococcus bacteria with catalase test? because almost streptococcus spp. of organisms are aerobic or microaerophilic (beta haemolytic strains).
Ravi Prasad ji
To differentiate the genus (Streptococcus or Staphylococcus), you can perform catalase test. Streptoccus spp is catalase Negative and Staphylococcus is catalase positive.
superb article..accurate and impressive
Sir i just need to know is it a journal or newspaper article because i have to write a report on it and i need a reference
Very impresses
Something to be careful of when doing Catalse is aerosolization of the organism…….ergo the bubbling.
Thank you so much for this. Finally have an answer for our Biochemistry :))
i tried the tube test and i got absolutely no results. but when i tried the slide test the effervescence came. why do you think this happened.
Very hard to say you exact reason on the basis of information you have provided. Please try again with fresh culture with both tube and slide test; adhering with exact protocol and share your results.
Tamara, sounds like you did not have a lot of growth in the tube and the hydrogen peroxide could have been diluted in the liquid media. Culture should be at least 24 hrs old with good growth try this protocol: http://www.microbelibrary.org/library/2-associated-figure-resource/3237-positive-tube-catalase-test
You can also drop a drop of hydrogen peroxide directly on the media if grown on TSA: http://www.microbelibrary.org/library/2-associated-figure-resource/3234-catalase-test-on-staphlococcus-aureus-streak-plate
and
http://www.microbelibrary.org/library/2-associated-figure-resource/3235-catalase-test-on-staphlococcus-aureus-streak-plate-enlarged-view
Thing to be cautious of 1). use a plastic loop or wood application since hydrogen peroxide can react with a metal loop…ie you could get a false positive., 2). some media reacts with hydrogen peroxide such as blood agar. So you could not drop the hydrogen peroxide directly on the plate. If you do the slide test make sure you do not carry over any agar (blood agar, etc) to avoid a false positive.
thank you so much for these useful information
thank you very very much
i took some useful contents in this article,,help me reference it cause i dont wanna be penalised for stealing others s work
Thank you for your comment. Here is the method of citation using APA format: Acharya, TS., (2013.Catalase test: principle, uses, procedure and results. Retrieved from http://microbeonline.com/catalase-test-principle-uses-procedure-results/
what about the use of 30% H202
While performing the catalase test on crude protein extract of drosophila species fed on a pomegranate juice supplemented diet and control, the absorbance decreased with time in the case of control but increased in the flies that recieved the polyphenol treatment. Would be great help if you could provide a possible explanation?
thank you sir for this help
Really sir you are doing a good job for all the medical lab technician.thank you sir.
Its easy to learn thank u
Very nice material easy to perform
I appreciate your efforts
Thanks.
Great information via this plate form
Sir tel me how to differentate when catalase test is performed
Thank you
thank you for the information, am impressed. kindly help me understand why the other catalases only break down H2O2 in 30s and not as the catalase in staph. could you also write on other culture media such as Todd-Hewitt broth, edward’s agar and tryptone soya broth.
Sir is there any difference in meaning between high titre sera, antisera?
Soooo.. is Moraxella Catalase positive??
Very good explanation
i am really impressed and have also learned a lot from your write up.
It made me passed excellently my microbiology end of semester exams.
hello my work on ornithobacterium rhinotracheale bacteria. I want any helpful information about its isolation and identification
I have the following question for you
1. Is all salmonella species are catalase positive
2. What are biochemical test use for the differentiation of salmonella and cetrobacter youngae
I want to check the growth of bacteria in the presence of methylene blue 0.1 %. but I am not confirmed about the formulation to make the media. I need your kind help. Thank You