Question

5. What is Nitrogen fixation? Mention the difference between nitrification and denitrification processes. Name the organisms involved in these processes

Answer 1

Nitrogen fixation is a process by which nitrogen in the air is converted into ammonia or related nitrogenous compounds. ... Nitrogen fixation is carried out naturally in the soil by a wide range of microorganisms termed diazotrophs that include bacteria such as Azotobacter, and archaea. 

 nitrification and denitrification are two important stages of the nitrogen cycle.Nitrification is the biological conversion of ammonium into nitrate. Denitrification is the biological conversion of nitrate into nitrogen gas. This is the main difference between nitrification and denitrification.

Pseudomonas, and Achromobacter are implicated as denitrifiers
Nitrosomonas, Nitrosococcus,Nitrobacter and Nitrococcus. These are nitrifiers.

Answer 2

Nitrogen fixation is a process by which nitrogen in the air is converted into ammonia or related nitrogenous compounds. Atmospheric nitrogen, is molecular dinitrogen, a relatively nonreactive molecule that is metabolically useless to all but a few microorganisms

Nitrification is the biological conversion of ammonium into nitrate. Denitrification is the biological conversion of nitrate into nitrogen gas. This is the main difference between nitrification and denitrification.

e. g. rhizopus