Question

In $N_2$ cycle, Pseudomonas denitrificans helps in

• A. nitrogen fixation
• B. producing elemental nitrogen
• C. oxidising ammonia to nitrite
• D. none of these

Answer 1

The correct option is B producing elemental nitrogen

Pseudomonas denitrificans helps in the process of denitrification.
Denitrification is the process in which nitrates present in the soil are reduced to gaseous nitrogen. Nitrogen fixation is the conversion of atmospheric nitrogen into usable compounds of nitrogen like nitrates, ammonia. Biological nitrogen fixation is carried out by microorganisms such as Nostoc, Anabaena, Azotobacter.
Oxidation of ammonia into nitrite is carried out by bacteria Nitrosomonas/Nitrococcus.