Related Experiment Video
Updated: Jul 15, 2026

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
[Study on nitrate-nitrogen removal and community analysis of denitrifying bacteria in downflow fixed-bed bioreactor]
Zheng Huang1, Xiaochun Chen, Hongyan Liu
1MOE Key Lab of Environment and Health, Institute of Environmental Medicine, Tongji Medical College, Huazhong University of Science & Technology, Wuhan 430030, China.
Objective:
To study the community of denitrifying bacteria and nitrate-nitrogen removal in downflow fixed-bed bioreactor.
Methods:
Porous ceramics were used as immobilization carrier. Optimum conditions for nitrate-nitrogen removal of downflow fixed-bed bioreactor were studied. Morphology of immobilized denitrifying bacteria was observed by scanning electron microscope and their community analysis were processed by 16S rDNA sequencing.
Results:
The optimum conditions for denitrification were T = 35 degrees C and pH8.0. NO3- -N was consumed 99% within the 10h while removal efficiency reached 91% and followed the zero-order kinetics in the first 4h. Majorities of denitrifying bacteria were bacillus. 16SrDNA homology analysis showed that denitrifying bacteria included P. putida, P. nitroreducens, S. maltophilia, C. testosteroni and Ochrobactrum sp etc.
Conclusion:
There were high nitrate-nitrogen removal efficiency and diversity of denitrifying bacteria in downflow fixed-bed bioreactor.
More Related Videos
Related Concept Videos
Microbial Wastewater Treatment
Inorganic Nitrogen Assimilation
Microbes and the Nitrogen Cycle
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
Bioreactor Design and Operational System
Biological Treatment of Effluent and Waste Water

