Bacteria ammonium oxidizing

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

Cork [283], Sublette [284], and others have identified a number of chemolithotrophic bacteria which oxidize elemental sulfur and use reduced or partially reduced sulfur compounds as an energy source, in the presence of various carbon sources (such as carbon dioxide or bicarbonate) and reduced nitrogen (e.g., ammonium ion). In the case of Cork et al. s work, the anaerobic photosynthetic bacterium Chlorobium thiosulfatophilum is used to convert sulfides to sulfate. The economics of this process was not favorable due to the requirement of light for the growth of the bacterium. 

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

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. 

Ward, B. B. (1982). Oceanic distribution of ammonium-oxidizing bacteria determined by immuno-fluorescent assay. Journal of Marine Research 40, 1155—1172. 

Isaka, K., Date, Y., Sumino, T. Y., Sohie, S., and Tsuneda, S. (2005). Growth characteristics of anaerobic ammonium-oxidizing bacteria in anaerobic biological filtrated reactor. Appl. Microbiol. Biotechnol. 70, 47-52. 

Recently research has revealed that nitrification is not exclusively associated with chemoautotrophic bacteria of the P and y proteobacteria, but occurs in many Crenarcheaota as well (Francis et al, 2005 Konneke et al, 2005 Wuchter et al, 2006) who may in fact may dominate this process in seawater (Wuchter et al, 2006) (see Chapter 5 by Ward, this volume). The extent that archael nitrification occurs in coral reef habitats remains to be determined. Ammonium oxidation has also been shown to occur anoxicaUy in some marine sediments at the expense of N02 (Thamdrup and Dalsgaard, 2002) (see Chapter 6, Devol, this volume). 

This process is termed Anammox for anaerobic ammonium oxidation and is catalyzed by a speciabzed group of planctomycetes bacteria first discovered in sewage reactors (Strous and Jetten, 2004). Again, the importance of Anammox in coral reef environments has not yet been considered. 

Jetten, M. S. M., Sliekers, O., Kuypers, M., Dalsgaard, T., van Niftrik, L., Cirpus, I., et al. (2003). Anaerobic ammonium oxidation by marine and freshwater planctomycete-hke bacteria. Appl. Microbiol. Biotechnol. 63, 107—114. 

Penton, C. R., Devol, A. H., and Tiedje, J. M. (2006). Molecular evidence for the broad distribution of anaerobic ammonium-oxidizing bacteria in freshwater and marine sediments. Appl. Environ. Microbiol. 72, 6829—6832. 

Schmid, M. C., Risgaard-Petersen, N., van de Vossenberg, J., Kuypers, M. M. M., Lavik, G., Petersen, J., et al. (2007). Anaerobic ammonium-oxidizing bacteria in marine environments widespread occurrence but low diversity. Environ. Microbiol. 9, 1476—1484. 

Many other carboxylation reactions exist (Barton et al., 1991). For example, in methylo-trophic bacteria, formaldehyde and CO2 are combined to produce acetyl-CoA in the serine or hydroxypyruvate pathway. In contrast, the ribulose monophosphate cycle, which is another methylotrophic pathway of formaldehyde fixation, does not involve carboxylation steps. In addition to those described above, commonly found carboxylation reactions include those of pyruvate or phosphoenol pyruvate. In view of several relatively recent discoveries of novel CO2 assimilation pathways (e.g., the hydoxypro-pionate cycle and anaerobic ammonium oxidation) and growing interest in deep-subsurface microbiology, novel pathways of CO2 incorporation may be discovered in the near future. 

Chlorobiaceae photosynthesis is via reversal of the citric acid cycle tchemotrophes include sulphur and ammonium oxidizing bacteria (see Box 1.7) teach additional heterotrophic step involves a similar fractionation methanogenesis generally leads to a fractionation of c.40%o in freshwater conditions but c.70%o under marine conditions. 

In addition to chemoautotrophs, methanotrophic bacteria are also capable of oxidizing ammonium to nitrate. Several similarities exist between methane oxidizers and autotrophic ammonium oxidizers (Figure 8.36). Numerous studies have shown that methane (CH4) oxidizers can cooxidize ammonium to nitrite, nitrate or both. Collectively, methylotrophs are bacteria that are capable of growth on one-carbon compounds as their sole carbon and energy source. Thus, methanotrophs are a group of methylotrophic bacteria that utilize methane as their sole source of carbon and energy. 

---