Flashcards in MIDTERM 2 Catalase Test Deck (10):
What is Superoxide Dismutase and its significance and problems?
Its an enzyme that protonates superoxide to form hydrogen peroxide. Hydrogen peroxide is also toxic
How is the hydrogen Peroxide Dealt with?
The enzyme catalase breaks apart the hydrogen peroxide into water and O2
Where can catalase be found?
its produced by and found in essentially all actively growing microbes capable of using oxygen for respiration
Where does catalase exist?
It exists close to the cell surface and attacks external hydrogen peroxide.
What cultures are most suitable for a catalase test and why?
Cultures not older than 24 hours because the enzyme seems most active during exponential growth.
How do you test for catalase?
add a couple of drops of 3% hydrogen peroxide directly on the colony and observe if there are bubbles
what can the catalase test distinguish?
It can distinguish between morphologically similar but metabolically dissimilar microorganisms like costridium and bacillus
Is bacillus catalase positive?
Is clostridia catalase negative?