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Updated: Jul 15, 2026
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A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Prolonged Stagnation Reduces Treated Wastewater Biostability by Altering Microbial Community: Insights From
Fatimah Almulhim1, Shaman Narayanasamy2, Changzhi Wang2
1Bioscience Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
Environmental Microbiology
|July 14, 2026
Summary
Hydraulic stagnation in reclaimed water systems disrupts microbial communities, reducing nitrogen cycling and promoting harmful bacteria. Maintaining water flow is crucial for safe wastewater reuse in irrigation and non-potable applications.
Area of Science:
- Environmental microbiology
- Water quality management
- Wastewater reclamation
Background:
- Reclaimed wastewater reuse for irrigation is increasing.
- Inadequately treated effluent and system stagnation pose environmental and public health risks.
- Hydraulic stagnation in distribution systems can destabilize microbial communities and promote pathogen persistence.
Purpose of the Study:
- To investigate the impact of prolonged hydraulic stagnation on microbial community structure and function in reclaimed wastewater biofilms.
- To compare microbial community dynamics under stagnant versus flowing conditions over extended periods.
Main Methods:
- Integrated metagenomics and metaproteomics analyses of biofilms.
- Comparison of microbial communities under stagnant and flow conditions over 3, 5, and 7 months.
Main Results:
- Prolonged stagnation significantly altered microbial composition, reducing nitrogen-removing taxa (e.g., Nitrospira, Nitrosomonas).
- Nitrification and denitrification proteins were depleted under stagnation, indicating impaired nitrogen cycling.
- Stagnation enriched motility functions, promoted persistence of phytopathogenic Acidovorax, and reduced contaminant-degrading enzymes.
- Flow conditions maintained nitrogen cycling, contaminant degradation, and biostability.
Conclusions:
- Prolonged stagnation disrupts microbial balance, suppresses essential nitrogen cycling and detoxification pathways.
- Stagnation reduces the functional robustness of treated wastewater.
- Maintaining hydraulic flow is critical for preserving microbial functionality and ensuring safe wastewater reuse.
Keywords:
biofilm microbiomehydraulic stagnationmetagenomicsmetaproteomicsmicrobial biostabilitytreated wastewaterMore Related Videos
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