Nitrite-oxidizing bacteria

The bacteria grow by oxidizing nitrite (NOD to nitrate (N03 ) (Fig. 1.8). Nitro-bacter winogradskyi is a typical species in this group. In addition to this, Nitrobac-ter hamburgensis, Nitrospina gracilis, Nitrococcus mobilis and others are known 

The reaction (1.2) is catalyzed by nitrite oxidoreductase. This enzyme catalyzes actively the oxidation of nitrite at pH 8.0, while it catalyzes more preferentially the reduction of nitrate at pHs below 6.0. Therefore, the pH of the environments should be kept around 8 (Tanaka et al., 1983) for the bacterium to oxidize smoothly nitrite. 

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AOB — Ammonia-oxidizing bacteria NOB - Nitrite-oxidizing bacteria IF — Immunofluorescence MPN — Most Probable Number... 

Daims, H., Nielsen,. L., Nielsen, P. H., Schleifer, K. H., and Wagner, M. (2001). In situ characterization of Nitrospira-like nitrite-oxidizing bacteria active in wastewater treatment plants. Applied and Environmental Microbiology 67, 5273—5284. 

Tal, Y., Watts, J. E. M., and Schreier, H. J. (2005). Anaerobic ammonia-oxidizing bacteria and related activity in Baltimore inner Harbor sediment. Applied and Environmental Microbiology 71, 1816—1821. Teske, A., Aim, E., Regan, J. M., Toze, S., Pattmann, B. E., and Stahl, D. A. (1994). Evolutionary relationships among ammonia- and nitrite-oxidizing bacteria. Journal of Bacteriology 176, 6623-6630. 

Ward, B. B., and Carlucci, A. p. (1985). Marine ammonium- and nitrite-oxidizing bacteria Serological diversity determined by immunofluorescence in culture and in the environment. Applied and Environmental Microbiology 50, 194—201. 

Fig. 1.8. A schematic presentation of the mechanisms by which the nitrite-oxidizing bacteria acquire energy and biosynthesize organic compounds...

Many nitrite-oxidizing bacteria have been discovered, for example Nitrobacter winogradskyi, Nitrobacter hamburgensis, Nitrospina gracilis, Nitrococcus mobilis, and Nitrospira marina, (Watson et al., 1989). Among them, N. winogradskyi is studied most extensively. 

Nitrite oxidoreductase has been purified also from Nitrobacter hamburgensis (Sundermeyer-Klinger et al., 1984) and Nitrospira moscoviensis (Spieck et al., 1998). The N. hamburgensis enzyme has been reported to have heme C but not to have heme A. It does not catalyze the reduction of horse ferricytochrome c with nitrite although it catalyzes the reduction of ferricyanide. The N. moscoviensis enzyme has been reported to have heme B but not to have either heme A or heme C. Although the N. moscoviensis enzyme catalyzes the oxidation of nitrite with chlorate as the electron acceptor, it has not been reported whether cytochrome c or ferricyanide acts as the electron acceptor for the enzyme. The enzyme of this bacterium is known to be located in the periplasmic space. Table 3.3 lists some properties of nitrite oxidoreductase purified from three species of the nitrite-oxidizing bacteria. 

Table 3.3. Comparison of nitrite oxidoreductases purified from three species of the nitrite-oxidizing bacteria...

Interaction Between Ammonia-Oxidizing and Nitrite-Oxidizing Bacteria... 

Nowadays, in Nature, approximately the same numbers of the ammonia-oxidizing and the nitrite-oxidizing bacteria are present in most cases, as already mentioned. So it may be attributable to the presence of approximately the same numbers of both the bacteria in Nature that nitrite does not accumulate by use of paraquat in the field. Namely, the effect of paraquat on the nitrifiers when both the... 

Nitrification is the commonly used term that combines the activity of two distinctly different groups of microorganisms ammonia oxidizing bacteria and nitrite oxidizing bacteria. In combination, these two groups of organisms convert ammonia to nitrate... 

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