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Updated: Jan 12, 2026

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Quorum sensing enhanced dissimilatory nitrate reduction to ammonia processes in constructed wetland-microbial fuel
Shuyuan Zhao1, Jun Yan1, Mengli Chen2
1Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
Abstract:
Constructed wetland-microbial fuel cells (CW-MFCs) enable nitrogen removal from wastewater treatment plant secondary effluents. Dissimilatory nitrate reduction to ammonium (DNRA) is a common biochemical process in CW-MFCs, but lacks full mechanistic understanding. This study found CW-MFC produced 3.9 ± 1.8 mg/L NH4+-N via DNRA, with NH4+-N concentration was positively correlated with N-acyl homoserine lactone (C4-HSL, an AHL; p < 0.05). C4-HSL enhanced DNRA by boosting electron availability, extracellular electron transfer, and periplasmic enzyme-encoding gene abundance, supported by DNRA-related microbes (e.g., Geobacter). Despite DNRA, CW-MFC achieved higher total nitrogen TN removal (76.9 ± 6.4 %) than CW (51.1 ± 4.4 %), positively correlated with plant growth (p < 0.05; 131.4 % higher net photosynthesis, 132.3 % higher root activity). This first molecular-level investigation of AHL-mediated DNRA highlights its potential for improving CW-MFC nitrogen elimination.
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