Question

Micro-organisms responsible for nitrification are

• A. Nitrosomonas and Nitrobacter
• B. Nostoc and Anabaena
• C. Rhizobium and Azotobacter
• D. Clostridium and Pseudomonas

Hint:

Remember: Nitrification involves two steps – ammonia to nitrite (Nitrosomonas) and nitrite to nitrate (Nitrobacter).

Answer 1

The Correct Option is A

Step 1: Nitrification Defined.
Nitrification is a two-step biological process: ammonia (\( NH_3 \)) is oxidized to nitrite (\( NO_2^- \)), which is then oxidized to nitrate (\( NO_3^- \)).
Step 2: Key Microorganisms.
- Nitrosomonas converts ammonia to nitrite.
- Nitrobacter converts nitrite to nitrate.
In summary, Nitrosomonas and Nitrobacter are the primary microorganisms mediating nitrification.
Final Answer: \[ \boxed{\text{Nitrosomonas and Nitrobacter}} \]