(a) List two bacteria which bring about nitrification.

(b) List one denitrifying bacteria.

(c) List any two bacteria which play a role in biological nitrogen fixation.

(a) Nitrification is the conversion of ammonia into nitrate. It is carried out by bacteria like Nitrobacter, amd Nitrocystis.

(b) Pseudomonas is a denitrifying bacteria that converts nitrates in soil to free atmospheric nitrogen.

(c) Azobacter, Cyanobacteria, Anabaena and Clostridium are some bacterias that play a role in biological nitrogen fixation i.e. they convert nitrogen in earth’s atmosphere to ammonia NH3.