Question

Which bacteria is responsible for the reduction of nitrates into nitrogen in soil?

• A. Nitrosomonas
• B. Pseudomonas
• C. Rhizobium
• D. None of the above

Answer 1

The correct option is B Pseudomonas

Organisms need nitrogen to produce amino acids. Most of the organisms can not use the atmospheric nitrogen and must need the fixed form. The nitrogen cycle includes the four main processes i.e., fixation, ammonification, nitrification and denitrification.

The nitrogen fixation is done by the symbiotic bacteria like Azotobacter, Rhizobium etc.

Ammonification is the process of decomposition of microbes, plants and animal biomass to produce ammonia. It is performed by the bacteria e.g., Bacillus species and fungi.

The conversion of ammonia to nitrite and then to nitrate is done by the bacteria Nitrosomonas and Nitrobacter respectively. This process is called as nitrification.

The reduction of nitrate back into nitrogen in the soil is called as denitrification. This process is performed by bacteria like Pseudomonas, Clostridium etc.