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A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
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Published on: December 25, 2015

Quantifying community dynamics of nitrifiers in functionally stable reactors.

Lieven Wittebolle1, Han Vervaeren, Willy Verstraete

  • 1Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium.

Applied and Environmental Microbiology
|November 6, 2007
PubMed
Summary
This summary is machine-generated.

This study compared sequential batch reactors (SBR) and membrane bioreactors (MBR) for nitrification. Results show neither reactor maintained a stable ammonia-oxidizing bacterial (AOB) community, with SBRs exhibiting more gradual shifts than MBRs.

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07:59

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Published on: December 6, 2018

Area of Science:

  • Environmental microbiology
  • Wastewater treatment technologies
  • Nitrification process dynamics

Background:

  • Nitrification stability in wastewater treatment is crucial for effluent quality.
  • Ammonia-oxidizing bacteria (AOB) are key players in nitrification.
  • Understanding microbial community dynamics is essential for optimizing treatment processes.

Purpose of the Study:

  • To investigate the relationship between nitrification stability and AOB community structure in SBR and MBR systems.
  • To evaluate novel methods for quantifying microbial community dynamics.
  • To compare the functional and microbial stability of SBR and MBR under ammonium-supplemented conditions.

Main Methods:

  • Parallel operation of a sequential batch reactor (SBR) and a membrane bioreactor (MBR) for 84 days.
  • Inoculation with municipal wastewater sludge and ammonium supplementation.
  • Analysis of nitrification performance and AOB community structure using denaturing gradient gel electrophoresis (DGGE).
  • Introduction of rate of change [Delta(t)((week))] and Pareto-Lorenz curve analysis for community dynamics.

Main Results:

  • The SBR maintained complete nitrification for most of the study period.
  • The MBR experienced nitrite accumulation from day 45 to 84.
  • Neither reactor exhibited a static AOB community; SBR showed slower weekly community changes (12.6%) compared to MBR (24.6%).
  • Pareto-Lorenz curves indicated a dominant AOB group in both reactors, especially the MBR, with less dominant species potentially acting as a reserve.

Conclusions:

  • Functional stability of nitrification does not necessarily correlate with a static AOB community.
  • The SBR demonstrated greater microbial community stability compared to the MBR.
  • Novel parameters like rate of change and Pareto-Lorenz curves are valuable tools for assessing activated-sludge system dynamics.
  • Wastewater treatment plant operators can utilize these parameters for improved system management.