Nitrosomonas bacteria

When organics containing reduced nitrogen are degraded, they usually produce ammonium, which is in equilibrium with ammonia. As the pK for NH3 NH4" is 9.3, the ammonium ion is the primary form present in virtually all biological treatment systems, as they operate at pH < 8.5 and usually in the pH range of 6.5-7.5. In aerobic reactions, ammonium is oxidized by nitrifying bacteria (nitrosomonas) to nitrite... 

Konig et al. [80-84] demonstrated that microbial sensors are suitable for the summary quantification of nitrifiable compounds (see also Sect. 3.3.1) as well as for the detection of nitrification inhibiting effects. Such biosensors, which contain a mixed population of the nitrifying bacteria Nitrosomonas sp. and Nitrobacter sp., exhibit a specific supplementary metabolic capacity. This enables the amperometric determination of ammonia according the following scheme of nitrification ... 

Fig. 12. The red copper site of nitrosocyanin from the bacteria Nitrosomonas europaea (PDB Accession Code IIBY).

The reactions in the nitrification process are mediated by two types of autotrophic bacteria Nitrosomonas and Nitrobacter. The ammonia comes from the nitrogen content of any organic substance, such as proteins, that contains about 16% nitrogen. As soon as the ammonia has been hydrolyzed from the organic substance, Nitrosomonas consumes it and in the process also consumes oxygen according to... 

From the amino acids, resulting from the decomposition of proteins, ammonia is liberated, and it is oxidized to nitrites and nitrates by nitrifying bacteria Nitrosomonas and Nitrobacter. Denitrifying bacteria produce molecular nitrogen from nitrates. Nitrogen fixation is performed by nitro-genic bacteria (Azotobacter) and cyanobacteria (Nostoc). 

Emergence of acidic environments is associated with the activity of nitrifying bacteria (Nitrosomonas and Nitrobacter), which oxidize ammonia or ammonium entering in sufficient quantity the underground space with sewage effluents, to nitrous and nitric acids. 

Nitrite is very important in N transformations because it is an intermediate product in aerobic nitrification by the bacteria Nitrosomonas and... 

Ammonia-oxidizing bacteria including Nitrosomonas europaea... 

Although the number of Nitrosomonas bacteria was greater than the number of Nitrobacter in each treatment plots, only Nitrobacter differed significantly among treatments (Table II). Both Nitrosomonas and Nitrobacter counts decreased significantly with sampled depths. 

One of the pitfalls of microbial sensors, viz. their low selectivity, can be overcome by combining cells with an immobilized enzyme. Thus, creatinine deaminase (CDA, EC 3.5.4.21) hydrolyses creatinine to N-methylhydantoin and ammonium ion, the ammonia produced being successively oxidized to nitrite and nitrate ion by nitrifying bacteria. These bacteria have not yet been characterized but are known to be a mixed culture of Nitrosomonas sp. and Nitrobacter sp. The reaction sequence involved is as follows ... 

As bacteria die, ammonia is typically produced as a product of decomposition. Aerobic nitrifying bacteria such as Nitrosomonas and Nitrobacter can oxidize ammonia (NH3) to nitrate (N03 ). As a result of this process, the pH of the system can be reduced. 

For the most part, nitrification involves the activity of two very different classes of bacteria (Wallace and Nicholas, 1969 Kuenen and Robertson, 1987). The first step, the 6-electron oxidation of NH, to nitrite (NO2 ), is carried out by a small numbet of genera of autotrophic bacteria, exemplified by Nitrosomonas the second step, the 2-electron oxidation of nitrite to nitrate (NO3 ) by a sim-... 

Aerobic, chemolithotrophic bacteria. Colorless sulfur bacteria Thiobacillus iron or manganese-oxidizing bacteria, magnetotactic bacteria nitrifying bacteria Nitrobacter, Nitrosomonas... 

---