Certain bacteria living in the soil convert nitrates into nitrites and then to free nitrogen. Such bacteria are termed as:

Correct option is B

· Denitrifying bacteria play a crucial role in the nitrogen cycle by converting nitrates (NO₃⁻) into nitrogen gas (N₂), releasing it back into the atmosphere.
· Examples of denitrifying bacteria include Pseudomonas and Clostridium species.
· Nitrogen-fixing bacteria (Rhizobium, Azotobacter) convert atmospheric nitrogen (N₂) into ammonia (NH₃), making it available for plants.
· Nitrifying bacteria (Nitrosomonas, Nitrobacter) help in converting ammonia into nitrites (NO₂⁻) and then into nitrates (NO₃⁻).
· Ammonifying bacteria help in decomposing organic matter and releasing ammonia.