Exercise 13: Catalase and Oxidase Tests

Question 1

Catabolism

Answer 1

breakdown of biochemicals to generate energy

Question 2

Catalase

Answer 2

• enzyme that detoxifies some of the harmful oxygen products

- present in bacteria that undergo cellular respiration

Question 3

Reactive Oxygen Species (ROS)

Answer 3

• harmful oxygen products
• hydroxyl radical (OH*)
• superoxide radical (O2*-)
• hydrogen peroxide (H2O2)

Question 4

Positive results (catalase)

Answer 4

• Staphylococcus and Micrococcus

- produce oxygen bubbles within seconds of reaction

Question 5

Negative results (catalase)

Answer 5

• Enterococcus

- no bubbles

Question 6

Oxidase

Answer 6

• is used in this lab to detect the presence of cytochrome c in the ETC.
• An oxidase swab coated with chromogenic reducing agent TMPD is used to swab the unknown colony on the TSA plate
• swab will turn blue if positive

Question 7

Neisseria

Answer 7

• N. gonorrhoeae –> gonorrhea

- N. meningitidis –> meningitis

Question 8

Vibrio

Answer 8

-V. cholerae –> cholera

Question 9

Acinetobacter

Answer 9

oxidase negative, catalase positive

-causes nosocomial infections and foodborne diseases

Question 10

Aeromonas

Answer 10

oxidase positive, catalase positive

-causes gastroenteritis, traveler’s diarrhea, wound infections, septicemia, respiratory infections, etc.