Index >> Nitrification and Denitrification >> Denitrification

Denitrification

Nitrogen transformations in soil result in the loss of molecular nitrogen. The conversion of nitrate and nitrite into molecular nitrogen or nitrous oxide through microbial processes is known as denitrification. The escape of molecular nitrogen into the atmosphere, also known as volatilization of nitrogen is a drain on the availability of this vital element in soil for crop growth.

Denitrification of bound nitrogen to gaseous nitrogen is mediated by numerous species of bacteria which normally use oxygen of the air as hydrogen acceptor (aerobically) but also possess the ability to use nitrates and nitrites in the place of oxygen (anaerobically). Thus these bacteria have the faculty to grow aerobically in the absence of nitrate but anaerobically in the presence of nitrate. The anaerobically conversion of nitrate into molecular nitrogen is also known as nitrate respiration. In fact such or­ganisms capable of denitrification are isolated by enrichment cultures in anaerobic media containing excess of potassium nitrate.