Question

Bacteria that convert ammonia to nitrite belong to

• A. Nitrobacter
• B. Nitrosomonas
• C. Pseudomonas
• D. Mycobacterium

Answer 1

The correct option is B Nitrosomonas

Nitrification is the phenomena of conversion of ammonium nitrogen to nitrate nitrogen. It is performed in two steps- nitrite formation and nitrate formation. In the first step, ammonium ions are oxidized to nitrites by bacteria Nitrosomonas. In the second step, nitrites are changed to nitrates e.g. Nitrobacter. Nitrates are converted back to nitrogen gas by Pseudomonas (denitrification). Mycobacterium is another group of bacteria that do not have the relationship with nitrogen fixation. It causes several diseases in humans e.g., tuberculosis by Mycobacterium tuberclosis.

Hence, the correct answer is option B.