Studies on anaerobic biphasic growth of a denitrifying bacterium, Pseudomonas stutzeri

Growth of Pseudomonas stutzeri(VAN NIEL strain) in the presence of a limiting amount of nitrate under anaerobic conditions is characterized by 2 logarithmic phases separated distinctly by an intermediate phase where the growth rate is very low. In the first logarithmic phase nitrate is reduced stoichiometrically to nitrite stage, and in the second phase nitrite is reduced to nitrogen gas. The nitrite reducing activity of cells in the second growth phase is 3–4 times higher than that of cells in the first phase. The rise in nitrite reducing activity is correlated with a remarkable increase in the content of cytochromes a2 and c-552.