Related Experiment Video
Updated: May 15, 2025

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations
Published on: August 3, 2016
Influent chemical oxygen demand to nitrogen ratio regulate microbial intercellular communication influencing partial
Wenxin Xu1, Wenhan Ma1, Sixin Zhang1
1Engineering Research Center of Low-Carbon Treatment and Green Development of Polluted Water in Northeast China, Ministry of Education, School of Environment, Northeast Normal University, Changchun 130117, China.
Abstract:
Achieving nitrite accumulation in mainstream municipal wastewater provides significant economic and ecological benefits. Acyl-homoserine lactones (AHLs)-mediated microbial interspecies signaling regulates activated sludge system performance and promotes nitrogen transformation processes, though their specific regulatory mechanisms influencing nitrite accumulation remain unclear. This study investigated nitrogen transformation and microbial interactions under varying chemical oxygen demand to nitrogen (COD/N) ratios through long-term cultivation and exogenous AHLs addition experiments. Results demonstrated that a COD/N ratio of 3 caused a 65.8 % nitrite accumulation ratio by significantly inhibiting nitrite-oxidizing bacteria (NOB) metabolism. Functional AHLs (3-OXO-C12-HSL and C6-HSL) and key partial nitrification-promoting microorganisms (Thauera and Ca. Accumulibacter) were identified. Exogenous AHLs addition experiments demonstrated that C6-HSL promotes nitrification activity while C12-OXO-HSL inhibits it. Notably, AHLs-mediated regulation exhibits stronger regulation on NOB than ammonia-oxidizing bacteria. This study provides a theoretical basis for developing partial nitrification through microbial community self-regulation in municipal wastewater treatment.
More Related Videos
Related Concept Videos
Calculating Equilibrium Concentrations
A more...
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...

