Question

Consider the following statements related to nitrification process:
\( (i) \, \text{Electron acceptor type vary depending on whether nitrosomonas or nitrobacter is involved.} \)
\( (ii) \, \text{Predominant carbon source is organic matter.} \)
\( (iii) \, \text{Predominant carbon source is inorganic carbon.} \)
\( (iv) \, \text{Electron donor during conversion of ammonium ions to nitrite ions is ammonium ions.} \)
Choose the correct option(s) from the following:

• A. (iii) and (iv) are correct
• B. (i) and (ii) are correct
• C. (i) is incorrect and (iii) is correct
• D. (ii) is correct and (iii) is incorrect

Hint:

In nitrification, ammonia acts as the electron donor, and the carbon source is inorganic carbon (CO₂).

Answer 1

The Correct Option is A, C

Step 1: Understanding the process of nitrification.
Nitrification occurs in two stages:
Ammonia (NH₃) is converted to nitrite (NO₂⁻) by the bacterium {Nitrosomonas}.
Nitrite (NO₂⁻) is further oxidized to nitrate (NO₃⁻) by the bacterium {Nitrobacter}.
Step 2: Analyzing the statements.
Statement (i): Incorrect. Both {Nitrosomonas} and {Nitrobacter} use oxygen as their electron acceptor, thus the electron acceptor is consistent for both.
Statement (ii): Incorrect. Nitrification primarily utilizes inorganic carbon (CO₂) rather than organic carbon sources.
Statement (iii): Correct. The primary carbon source in nitrification is inorganic carbon (CO₂).
Statement (iv): Correct. Ammonium ions act as the electron donor in the conversion of ammonium to nitrite.
Step 3: Final Conclusion.
The accurate statements are (iii) and (iv), so the correct answer is both (A) and (C).