Non-enzymatic Formation of Nitrogen Gas

SINCE comprehensive treatment of the biochemical reduction of nitrate of Gayon and Dupetit 1 it has been generally assumed in denitrification studies that nitric oxide, and particularly nitrogen gas, evolved either from cell preparations or soil systems under moderate conditions of acidity ( p H 5.0–7.0) and temperature (28°-30° C), are dissimilatory products of ‘nitrate or nitrite respiration’ 2–4 . Recent evidence has shown, however, that nitric oxide can also be formed from nitrite in sterile, moderately acid systems when certain transition-like metals are present 5 . Subsequent experiments to be presented in this communication further indicate that nitrogen gas can be formed as a result of reacting potassium nitrite and ferrous sulphate.