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Updated: Aug 6, 2026
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A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Microbial community development in a laboratory-scale nitrifying activated sludge system with input from a
1Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA. smr0@email.uc.edu
Summary
Adding biomass from side-stream reactors significantly influences ammonia oxidizing bacteria (AOB) populations in main-stream sewage treatment. The AOB in side-stream reactors strongly impact the main-stream reactor
Area of Science:
- Environmental Microbiology
- Wastewater Treatment Engineering
Background:
- Activated sludge processes are crucial for sewage treatment.
- Understanding microbial community dynamics is key to optimizing treatment efficiency.
- Ammonia oxidizing bacteria (AOB) play a vital role in nitrification within these systems.
Purpose of the Study:
- To investigate the impact of side-stream reactor biomass on main-stream activated sludge biodiversity.
- To determine the influence of different side-stream reactor configurations (CSTR, PFR) on AOB populations.
- To assess the stability and transfer of AOB communities in integrated treatment trains.
Main Methods:
- Operated three laboratory-scale activated sludge treatment trains with varying side-stream reactor inputs.
- Utilized polymerase chain reaction (PCR) amplification of the ammonia monooxygenase subunit A (amoA) gene.
- Employed restriction fragment length polymorphism (RFLP) analysis using polyacrylamide gel electrophoresis (PAGE).
- Generated dendrograms using Jaccard distance to analyze AOB community similarity.
- Sequenced amoA genes to identify dominant AOB species.
Main Results:
- AOB populations stabilized within four months across all reactors.
- AOB communities in side-stream reactors showed high similarity to their respective main-stream reactors.
- The type of side-stream reactor (CSTR vs. PFR) influenced the dominant AOB species.
- Nitrosomonas europea was dominant in the PFR side-stream, while N. europea and N. marina were prominent in the CSTR side-stream.
Conclusions:
- Biomass seeding from side-stream reactors significantly shapes AOB populations in main-stream activated sludge.
- Side-stream reactor configuration dictates the specific AOB taxa transferred and established.
- This approach offers a method to potentially manage and optimize nitrification in wastewater treatment plants.
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