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Updated: Feb 3, 2026

Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading
Published on: March 6, 2014
Competitive nitrogen/phosphorus scarcity triggers multi-pathway nitrogen removal and phosphorus-stress response in
Lili Yang1, Wenqian Wei2, Xin Sun1
1School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Abstract:
This study elucidates the metabolic remodeling and synergistic mechanisms of the microalgae-bacteria symbiosis (MABS) under competitive nitrogen and phosphorus stress. Compared with the control, MABS increased removal efficiencies of total nitrogen, NH4+-N, NO3--N, and total phosphorus by 5.9, 5.1, 1.5, and 1.7 times, respectively, while enhancing microalgal triacylglycerol production by 17.5%. Microalgae preferentially assimilated NH4+-N and dominated phosphorus uptake, whereas the bacterial community strengthened denitrification through functional specialization, carbon metabolism optimization, and electron transport chain (ETC) remodeling. Specifically, bacterial carbon metabolism shifted from the conventional tricarboxylic acid cycle toward a frdABCD-dependent branch that supplies reducing power, accompanied by the enrichment of electron carrier ubiquinone-10 and upregulation of ETC complexes III/IV. Symbiotic bacteria further promoted more efficient ATP synthesis in microalgae, synergizing with improved carbon fixation and lipid-directed carbon partitioning. These findings reveal the metabolic plasticity and cross-kingdom coordination that underpin high-rate nutrient removal and lipid accumulation in MABS.
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