Question

Which of the following is/are the example of nitrifying bacteria?

• A. Nitrosomonas
• B. Nitrobacter
• C. Nitrospira
• D. Nitrosomonas, Nitrobacter, Nitrospira

Hint:

Nitrification is an aerobic process, meaning it requires well-aerated soils to convert toxic ammonia and nitrite into nitrate.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Nitrification is a biological process where reduced nitrogen compounds (primarily ammonia) are oxidized to nitrite and subsequently to nitrate.

Step 2: Detailed Explanation:
Nitrifying bacteria are chemolithoautotrophic organisms that drive the nitrification process in two steps:
1. Ammonia-oxidizing bacteria, such as Nitrosomonas, convert ammonia (\(\text{NH}_4^+\)) to nitrite (\(\text{NO}_2^-\)).
2. Nitrite-oxidizing bacteria, such as Nitrobacter and Nitrospira, convert toxic nitrite (\(\text{NO}_2^-\)) to stable nitrate (\(\text{NO}_3^-\)).
All three genera are essential members of the nitrifying community in soil.

Step 3: Final Answer:
Thus, all of the listed organisms are nitrifying bacteria, making Option (D) the correct answer.