To understand the function of catalase in cells that produce the enzyme, interpret the results of a catalase test and know their value in differentiating bacteria.
Materials: .
1 clean microscopic slide, 3% H2O2 solution, swabs. Micrococcus luteus, Enterococcus faecalis, patient G.
Procedure:.
1) Scrape some cells off from each bateria to the slant and place them on glass slide. .
2) Place one or two drops of H2O2. Watch for bubbling as an indication of O2 production. .
3) Discard the used slide container.
Results: .
Organisms Bubbles formation Catalase.
Patient G Bubbles Positive.
Micrococcus luteus Bubbles/O2 formed Positive.
Enterococcus faecalis No bubbles/No O2 Negative.
Observations:.
When H2O2 is added to Micrococcus luteus it shows the formation of bubbles which shows production of oxygen. It is catalase positive. .
In addition of H2O2 Patient G cells also show positive reaction forming oxygen and water which means it decomposes hydrogen peroxide into water and oxygen. Also catalase positive. Enterococcus faecalis doesn't show produce bubbles in addition of H2O2 which means it doesn't produce oxygen and is catalase negative.
Conclusion/Interpretation:.
Bubbles appeared after placing H2O2 shows positive reaction to the catalase enzyme. Depending on the strength of the reaction, the bubbles may be tiny or relatively large. The primary reaction catalyzed by catalase is the decomposition of hydrogen peroxide to form water and oxygen, which occurs spontaneously, but not at a very rapid rate.
Title:.
Oxidase Enzyme Detection.
Objective.
Explain the chemical basis for the oxidase test, and interpret reactions in the oxidase test. Purpose is to determine if the bacterium has cytochrome c oxidase in its electron transport chain.
Materials:.
1 paper towel, loops, oxidase reagent dropper, E.coli, Pseudomonas Aeruginosa.
Procedure: .
Take each organism on a loop and add the oxidase reagent to each loop. The area with smeared cells will start to turn blue and continue to get progressively darker.
