You have isolated a bacterium that grows in a medium containing only inorganic nutrients. Ammonia is oxidized to a nitrate ion. This bacterium is
A) gram- negative.
B) a photoheterotroph.
C) a photoautotroph
D) using anaerobic respiration.
E) a chemoautotroph.

Question

Quizplus · Accepted Answer

The bacterium in question is capable of growing in a medium containing only inorganic nutrients and oxidizing ammonia to a nitrate ion. This indicates that it is a chemoautotroph, as it is obtaining energy from inorganic compounds and using carbon dioxide as its carbon source. It is not a photoheterotroph, photoautotroph, or using anaerobic respiration, as none of these processes involve the oxidation of ammonia to a nitrate ion. The question does not provide any information regarding the gram-stain test, so we cannot determine if the bacterium is gram-negative or not.

You Have Isolated a Bacterium That Grows in a Medium