Nitrate-reducing microorganisms

Timmer-Ten Hoor A. (1975) A new type of thiosulphate oxidizing, nitrate reducing microorganism Thiomicrospira denitrificans. Neth. J. Sea Res. 9, 351 -353. 

Only a few studies have been undertaken on the role of bacteria in nitrosation at neutral pH in the Intestinal tract itself. Hashimoto al. (9 ) demonstrated that by changing the equilibrium between different species of microorganisms in the gut, (by administration of antibiotics and inoculation with nitrate-reducing strains) dimethylnitrosamine (NDMA) accumulated in the stomach and cecum of rats fed dlmethylamine (DMA) and nitrate. The authors describe only one experimental group, however, and the mechanism of NDMA formation is not clear. 

Table 3 lists the predominant microorganisms in both DNA and RNA profiles for the control batch at T=0. Both DNA and RNA analysis of the nitrate microcosm at T=3 days showed substantial shifts in community composition (Table 4), with Arcobacter sp. dominating in both cases. Arcobacter sp. are known as nitrate reducers since they play a role in nitrogen fixation, so this shift is consistent with sediment conditions. A couple of additional nitrate-reducing bacteria. Pseudomonas sp. and Nisaea denitrificans, were also identified. 

Nitrite (NO ) It is a relatively short-lived form of nitrogen. It is converted to nitrate by microorganisms. It is readily soluble in water and highly mobile in soil. Nitrite is rapidly oxidized to nitrate in aerobic environments or reduced to nitrous oxide in anaerobic soil environments. 

Alvarez, P.J. Vogel, T.M. (1995). Degradation of BTEX and their aerobic metabolites by indigenous microorganisms under nitrate reducing conditions. Water Science and Technology, Vol.31, pp. 15-28... 

The microorganisms reduce the nitrate and produce sulfuric acid, which eventually dissolves the rock formation, thus releasing oil. The microorganisms can be denitrifying thiobacilli, such as T. denitrificans [1667]. 

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