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Extraction of Structural Extracellular Polymeric Substances from Aerobic Granular Sludge
Published on: September 26, 2016
Microbial extracellular polymeric substances (EPS) in fresh water sediments
Sabine Ulrike Gerbersdorf1, Bernhard Westrich, David M Paterson
1Hydraulic Laboratory, Institute of Hydraulic Engineering, Universitaet Stuttgart, Pfaffenwaldring 61, Stuttgart 70550, Germany. sabine.gerbersdorf@iws.uni-stuttgart.de
Microbial Ecology
|February 27, 2009
Summary
Extracellular polymeric substances (EPS) in river sediments are produced by microbes and algae, influencing sediment ecology. Their composition and distribution vary spatially and with depth, indicating fresh production in upper layers and accumulation of degraded material deeper down.
Area of Science:
- Environmental Microbiology
- Geochemistry
- River Ecology
Background:
- Microbially produced extracellular polymeric substances (EPS) are crucial for ecological functions in sediments, but most research focuses on marine systems.
- Limited understanding exists regarding EPS dynamics in freshwater riverine sediments.
Purpose of the Study:
- To comprehensively study the spatial, temporal, and vertical patterns of EPS (carbohydrates and proteins) in European riverine sediments.
- To investigate the relationship between microbial communities, hydrodynamic regimes, and EPS production and composition.
Main Methods:
- Sampling across six reservoirs and four groyne fields in three European rivers over three years (2003-2005).
- Analysis of EPS composition (carbohydrates and proteins) and microbial biomass (microphytobenthos and bacteria) at various depths (up to 50 cm).
- Statistical analysis to determine relationships between environmental factors, microbial communities, and EPS characteristics.
Main Results:
- Hydrodynamic variations influenced benthic microbial biomass and EPS composition.
- Higher algal biomass correlated with increased colloidal carbohydrates, supporting existing models.
- Bacterial cell counts were closely related to algal biomass, suggesting bacterial utilization of EPS.
- EPS production varied with depth, with fresh substances in upper layers and refractory material in deeper layers.
Conclusions:
- EPS play a significant role in riverine sediment ecology, with distinct spatial and vertical distribution patterns.
- Both microphytobenthos and bacteria contribute to the EPS pool in river sediments.
- The refractory nature of EPS in deeper sediment layers suggests accumulation and limited bioavailability.
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