5.6: Nitrate Reduction Test Flashcards
In the case of a negative result after adding Reagents A and B, what additional reagent is added to test for the presence of unreduced nitrate?
-zinc dust
What is the function of the zinc powder in the nitrate reduction test?
-to serve as a chromogenic reducing agent
Which type of bacteria is commonly tested using the Nitrate Reduction Test?
-Denitrifying bacteria
What is the end product of the complete reduction of nitrate in the Nitrate Reduction Test?
-nitrogen gas (N2)
When all the possible steps of the nitrate reduction test are complete and the culture tube still fails to produce a color change, this indicates the organism:
-Is capable of nitrate reduction.
If a bacterial culture turns red immediately after the addition of the zinc dust, what does this result indicate?
-Negative nitrate reduction
What is the main function of reagent A and B in the Nitrate Reduction Test?
-Detect the presence of nitrite
The presence of gas in the Durham tube in a nitrate reduction test indicates that the organism:
-Has performed denitrification.
What is the color of the reagent that confirms the presence of unreduced nitrate in the test tube after adding zinc?
-colorless
What is the enzyme responsible for the reduction of nitrate to nitrite in the Nitrate Reduction Test?
-nitrate reductase
Why is the Nitrate Reduction Test useful in environmental microbiology?
-It assesses the ability of bacteria to denitrify and remove nitrate from the environment.
What is the purpose of the Nitrate Reduction Test?
-Determine the ability of bacteria to reduce nitrate to nitrite or other nitrogenous compounds
What is the function of the zinc powder in the nitrate reduction test?
-act as a catalyst
In the first step (after adding reagents A and B), what color change indicates a positive result in the Nitrate Reduction Test?
-clear to red
The presence of gas in the Durham tube in a nitrate reduction test indicates that the organism:
-Has performed denitrification.
