Denitrification cell biology

Zumft, W. G. (1997). Cell biology and molecular basis of denitrification. Microbiol. Molecul. Biol. Rev. 61(4), 533-616. 

Zeyer, J. Kuhn, E.P. Schwarzenbach, R.P. (1986). Rapid microbial mineralization of toluene and 1,3-dimethylbenzene in the absence of molecular oxygen. Applied and Environmental Microbiology, Vol.52, pp. 944-947 Zumft, W.G. (1997). Cell biology and molecular basis of denitrification. Microbiology and Molecular Biology Reviews, VoL61, pp. 533-616... 

Zumft WG. 1997. Cell biology and molecular basis of denitrification. Microbiol Mol... 

Figure 4.1 shows that NOs" is the stable form of nitrogen over the usual range of pe + pH in aerobic environments. The fact that most of the N2 in the atmosphere has not been converted to NO3 therefore indicates that the biological mediation of this conversion in both directions is inefficient. Hence NO3 reduction to N2 occurs by indirect mechanisms involving intermediaries. Dissimilatory reduction of N03 (i.e. where the nitrogen oxide serves as an electron acceptor for the cell s metabolism but the N reduced is not used by the microbes involved) potentially occurs by two processes denitrification. 

Soils inclnding wetland soils are important sonrces of atmospheric nitrous oxide. A wide range of processes may produce nitrous oxide, as well as minor amounts of NO, but not all of these seem to be fully understood. The main biological processes of nitrous oxide formation in soils are shown in Figure 16.5. They include nitrification, denitrification, the dissimilatory reduction of nitrate to ammonium, and the assimilatory reduction of nitrate wherein N is incorporated in the cell biomass. Additionally, some NO and nitrous oxide may be released due to chemo-denitrification and pyro-denitrification. Of these processes, nitrification and denitrification are the most important with respect to nitrous oxide production. 

Online monitoring and control of the biological denitrification process in a cell recyle membrane reactor has been developed and implemented at laboratory scale. The system has been tested with a real groundwater contaminated with nitrate. It is shown that a simple feedforward control strategy that adjusts the feed rate of the carbon source to maintain the optimum inlet carbon/nitrate ratio value is effective at reducing both nitrate and nitrite concentrations in the treated water below the maximum admissible values. 

To develop and implement an on-line monitoring strategy for the biological denitrification process in a cell recycle membrane bioreactor ... 

Clauwaert, R, Rabaey, K., Aelterman, R, De Schamphelaire, L, Rham, T.H., Boeckx, R, Boon, Ni. Verstraete, W. Biological denitrification in microbial fuel-cells. Environ. Sci. Technol. 41 (2007), pp. 3354-3360. 

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