Hydroxylamine as an Intermediate in Nitrification

Experiments carried out on washed suspensions of Nitrosomonas in this laboratory have shown that while hydroxylamine is toxic to the nitrification of ammonia, and is not itself nitrified at concentrations in excess of a few micrograms nitrogen per millilitre, yet at concentrations below about 1.5 µgm, it is nitrified as rapidly as ammonia and is thus a possible intermediate in the nitrified process.