GROWTH AND AUTOTROPHIC METABOLISM OF NITROSOMONAS EUROPAEA

Abstract

The chemoautotrophic nitrifying bacterium, N. europaea, was cultivated in a medium entirely free of particulate constituents. The short generation time and the long logarithmic growth phase observed under these conditions demonstrate that the organism has no absorption requirement for proliferation. Cell suspensions actively oxidize both hydroxylamine and ammonium N. Since hydroxylamine is oxidized by ammonium-grown cultures with no lag period and its oxidation to nitrite is quantitative, it is suggested that hydroxylamine is an intermediate in nitrificiation.