Related Experiment Video
Updated: Apr 15, 2026
Extraction of Structural Extracellular Polymeric Substances from Aerobic Granular Sludge
Published on: September 26, 2016
Optimization for extracellular polymeric substances extraction of microbial aggregates
Liang Zhu1, Haitian Yu2, Yimei Liu3
1Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China E-mail: felix79cn@hotmail.com; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou, 310058, China.
Comparing three methods for extracting extracellular polymeric substances (EPS) from microbial aggregates, researchers found ultrasound with formamide/NaOH or heat effectively captured polysaccharides and proteins. The ultrasound + CER + sulfide method was less effective for these EPS components.
Area of Science:
- Environmental Science
- Microbiology
- Biochemistry
Background:
- Extracellular polymeric substances (EPS) are crucial macromolecular components in microbial aggregates.
- Understanding EPS composition is key to microbial aggregate structure and function.
Purpose of the Study:
- To evaluate and compare three distinct methods for extracting EPS from microbial aggregates.
- To analyze the component differences in EPS extracted from loose flocs and dense aerobic granules.
Main Methods:
- Investigated three EPS extraction techniques: ultrasound + cation exchange resins (CER) + sulfide, ultrasound + formamide + NaOH, and ultrasound + heat.
- Utilized chemical analysis and three-dimensional excitation-emission matrix (3D-EEM) for component comparison.
Main Results:
- Ultrasound + formamide + NaOH and ultrasound + heat methods effectively extracted EPS components, including polysaccharides (PS) and proteins (PN).
- The ultrasound + CER + sulfide method showed limited effectiveness in extracting PS and PN.
- 3D-EEM identified PN-like, humic acid-like, and fulvic acid-like fluorophores, all detectable in EPS extracted via the ultrasound + heat method.
Conclusions:
- The ultrasound + formamide + NaOH and ultrasound + heat methods are superior for comprehensive EPS extraction.
- The ultrasound + heat method allows for the detection of diverse fluorophores within EPS.
- Findings offer insights into the EPS interaction mechanisms within microbial aggregates.
