Soil bacteria are responsible for any steps in the nitrogen

Soil bacteria are mainly involved in four steps in nitrogen cycle.

Nitrogen :First of all atmospheric nitrogen is fixed by soil bacteria (N2 to NH3/ NH4+, NO3-)Nitrification: The conversion of ammonium to nitrate is performed primarily by soil-living bacteria and other nitrifying bacteria (NH3 to NO3-)When a plant or animal dies or an animal expels waste, the initial form of nitrogen is organic. Bacteria or fungi convert the organic nitrogen within the remains back into ammonium (NH+4), a process called ammonification.Denitrification is the reduction of nitrates back into nitrogen gas (N2), completing the nitrogen cycle. This process is performed by bacterial species such as Pseudomonas and Clostridium in anaerobic conditions.