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Updated: Jun 26, 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 denitrification characterization of Thiobacillus denitrificans]
Xuan Che1, Guo-Zhi Luo, Hong-Xin Tan
1College of Aqua-life and Technology, Shanghai Fisheries University, Shanghai 200090, China. dandan_zw@tom.com
Abstract:
A autotrophic denitrifying bacterial strain, TD, was isolated from soil and the strain was identified and characterized. The strain was gram negative, strictly chemolithoautotrophic, and short rod shaped bacterium. The 16S rDNA sequence analysis revealed that strain TD had a similarity of 99.85% with Thiobacillus denitrificans. According to the morphologic, physiobiochemical characteristics and the analysis of its 16S rDNA, the strain was identified as Thiobacillus denitrificans. Studies showed that the optimal conditions for denitrification were pH 6.85 and 32.8 degrees C, while the optimal growth conditions were pH 6.90 and 29.5 degrees C. The bacteria grew slowly with no apparent stable phase. The maximal denitrification rate reached 2.245 mg x (L x h)(-1) which was found in exponential phase. In the process of the culture, the medium pH decreased significantly. Relatively high salinity restrained the denitrification activity of Thiobacillus denitrificans. The acute toxicity test results showed that Thiobacillus denitrificans was non-toxic.
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