Ammonium oxide

Giiven D et al. (2005) Propionate oxidation by and methanol inhibition of anaerobic ammonium-oxidizing bacteria. Appl Environ Microbiol 71 1066-1071. 

Cope Elimination oxidize 3° amine to tertiary ammonium oxide (R N -< V I. heat produces RHC=CH2... 

The biogeochemical cycling of nitrogen is very much controlled by redox reactions. This perspective is presented in Figure 24.3 for the redox reactions that take place in the water column and sediments. The major pathways of reduction are nitrogen fixation, assimilatory nitrogen reduction, and denitrification. The major oxidation processes are nitrification and anaerobic ammonium oxidation (anammox). Each of these is described next in further detail. 

Annamox Anaerobic ammonium oxidation. This process is mediated by bacteria. 

NH2C1 has been carefully studied by microwave spectroscopy and SCF calculations of its molecular properties using an essentially DZ basis have been recently reported.110 The barrier to inversion was computed and analysed in terms of the different contributions to the barrier. The main conclusion was that the barrier is attractive in Allen s terminology.111 The dipole and quadrupole moments were also computed in this paper. Hydroxylamines have been investigated previously,112 113 but in a more recent paper, Trindle and Shillady114 have computed the potential surface for the interconversion of ammonium oxide with hydroxylamine [equation (4)]. 

Voytek, M. A., B. B. Ward, and J. C. Priscu. 1998. The abundance of ammonium-oxidizing bacteria in Lake Bonney, Antarctica determined by immunofluorescence, PCR and in situ hybridization. In Ecosystem Dynamics in a Polar Desert. The McMurdo Dry Valleys, Antarctica (J. C. Priscu, Ed.), pp. 217—228. Am. Geophys. Union, Washington, DC. 

Figure 10.5 Major processes involved in the biogeochemical cycling of N in estuaries and the coastal ocean (1) biological N2 fixation (2) ammonia assimilation (3) nitrification (4) assimilatory NC>3 reduction (5) ammonification or N remineralization (6) ammonium oxidation (speculative at this time) (7) denitrification and dissimilatory NO3 reduction to NH4+ and (8) assimilation of dissolved organic nitrogen (DON). (Modified from Libes, 1992.)...

Ammonium oxidation (anammox) anaerobic NH4+ oxidation with NO3 this may be another mechanism whereby N is lost from natural systems. 

Mulder, A., van de Graaf, A.A., Robinson, L.A., and Kuenen, J.G (1995) Anaerobic ammonium oxidation discovered in denitrifying fluidized bed reactor. FEMS Microbiol. Ecol. 16, 177-184. 

Thamdrup, B., and Dalsgaard, T. (2002) Production of N2 through anaerobic ammonium oxidation coupled to nitrate reduction in marine sediments. Appl. Environ. Microbiol. 68, 1312-1318. 

Identification Dissolve 1 g of sample in 5 mL of 1 2 hydrochloric acid, and add an excess of 1 A sodium hydroxide. A red-brown precipitate forms. Boil the mixture, filter to remove the iron, and strongly acidify a portion of the filtrate with hydrochloric acid. Cool, mix with an equal volume of magnesia mixture TS, and treat with a slight excess of 6 A ammonium oxide. An abundant white precipitate forms. This precipitate, after being washed, turns green-yellow when treated with a few drops of silver nitrate TS. 

Ammonium oxide.—No oxide corresponding with ammonium hydroxide has been prepared with certainty (compare ammonium hydroxide). 

Kuypers, M. M. M., Lavik, G., Wobeken, D., Schmid, M., Fuchs, B. M., Amann, R., Jorgensen, B. B., and Jetten, M. S. M. (2005). Massive nitrogen loss from the Benguela upweUing system through anaerobic ammonium oxidation. Proceedings of the National Academy of Sciences 102 (18), 6478-6483. 

NO is not known to be an obligate intermediate during ammonium oxidation. It can be produced by AOB but the mechanism is not well known, see also section NO in the ocean above). During autotrophic nitrification N2O can be formed by AOB either via the pathways NH2OH —> N2O and NO N2O (Arp and Stein, 2003 Stein and Yung, 2003) or via the pathway NO2 NO —N2O (the latter is part of... 

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