Related Experiment Video
Updated: Jan 17, 2026

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Unveiling Fe reduction-induced synergy between anaerobic ammonium oxidation and Fe-Reducing/Oxidizing bacteria for
Xiaojing Hao1, Wei Zeng1, Qingteng Gong1
1National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Department of Environmental Engineering, Beijing University of Technology, Beijing 100124, China.
Abstract:
Anammox (anaerobic ammonium oxidation) provides an energy-efficient approach to wastewater treatment but is limited by unstable nitrite supply and nitrate accumulation. This study developed an innovative iron-nitrogen (Fe-N) coupled system that achieved 97 % total nitrogen removal using a low NO2--N/NH4+-N molar ratio of 0.75 and 3.69 mM Fe2O3 addition. Isotopic tracing and molecular analyses revealed a synergistic nitrogen removal network: Anammox contributed 67 % of NH4+-N oxidation, while Feammox (Fe(III) reduction coupled with anaerobic ammonium oxidation) played a complementary role under NO2--N-limiting conditions. The Fe(II) generated through Feammox facilitated NO3--N reduction to NO2--N via nitrate-dependent Fe(II) oxidation, effectively recycling substrates and maintaining iron cycling. Transcriptomic profiling further confirmed Feammox activity in Candidatus Brocadia and Candidatus Kuenenia, highlighting enhanced collaboration between anammox and iron-cycling bacteria. This iron-mediated microbial synergy offers a sustainable and efficient strategy for advanced wastewater treatment.
More Related Videos
Related Concept Videos
Metabolism of Chemolithotrophs
Inorganic Nitrogen Assimilation
Environmental Applications of Microorganisms
Microbial Nutrition
Anoxygenic Photosynthesis
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...

