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Updated: Jun 28, 2026

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
[Isolation, identification and characterization of nitroso-bacteria in one-step completely nitrogen removal process]
Jinsong Guo1, Yu Qin, Fang Fang
1Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China. Guo0768@cqu.edu.cn
Objective:
To study the characteristics of the Nitroso-bacteria in one-step completely autotrophic nitrogen removal process.
Methods:
We took samples from activated sludge of the one-step completely autotrophic nitrogen removal reactor. Through four times of enrichments and isolations, one Nitroso-bacteria named N1 was obtained. We identified this strain by microscope and 16S rDNA analysis and studied the effect of pH, temperature as well as ammonium concentration on the metabolism of N1.
Results:
Of the N1 nucleotides, 97%, 96% and 96% were identical with the conserved fragment of Nitrosomonas sp. NL7 (AY958677), Nitrosomonas AS1 (EF016119) and Nitrosomonas sp. Is32 (AJ621027) respectively. The optimal temperature and pH of N1 were 8.0 and 30 degrees C and sufficient dissolved oxygen was demanded. In addition, no restraint effect was turned up in the ammonium concentration of 80-800 mg/L.
Conclusion:
N1 was identified as Nitrosomonas sp. Compared with the relative references, this strain was ammonium-tolerant.
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