Question

Nitrification is a two-step process which refers to the conversion of ammonium (\(\text{NH}_4^+\)) to nitrate (\(\text{NO}_3^-\)).
(A). Nitrification is a two-step process which refers to the conversion of ammonium (\(\text{NH}_4^+\)) to nitrate (\(\text{NO}_3^-\)).
(B). In the first step, Nitrosomonas (obligate autotrophic bacteria) convert ammonium (\(\text{NH}_4^+\)) to nitrite (\(\text{NO}_2^-\)).
(C). The second step of nitrification occurs through Nitrobacter and Nitrosolobus species, which convert nitrite (\(\text{NO}_2^-\)) to nitrate (\(\text{NO}_3^-\)).
(D). The second step of nitrification occurs through Nitrobacter species only, which convert nitrite (\(\text{NO}_2^-\)) to nitrate (\(\text{NO}_3^-\)).
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only.
• B. (A), (B) and (C) only.
• C. (A), (C) and (D).
• D. (B), (C) and (D) only.

Hint:

To remember the biological actors in nitrification:
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Step 1: Nitroso- genus (Nitrosomonas, Nitrosolobus, Nitrosococcus) oxidizes \(\text{NH}_4^+\) to \(\text{NO}_2^-\).
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Step 2: Nitro- genus (Nitrobacter, Nitrospira) oxidizes \(\text{NO}_2^-\) to \(\text{NO}_3^-\).

Answer 1

The Correct Option is A