Hydrophobic features of EPS extracted from anaerobic granular sludge: an investigation based on DAX-8 resin fractionation and size exclusion chromatography
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The hydrophobic fractionation of extracellular polymeric substances (EPS) extracted from anaerobic granular sludge was performed on the DAX-8 resin (two elution pH conditions, i.e., pH 2 and pH 5 were tested). The impact of seven different EPS extraction methods on EPS hydrophobicity features was assessed. The results showed that the extraction methods and bulk solution pH influenced dramatically the biochemical composition of the EPS, and in turn, the hydrophobicity determined. Besides, EPS extracting reagents i.e., formaldehyde, ethanol, sodium dodecyl sulfate (SDS), and Tween 20 not only introduced extra carbon content in the total organic carbon (TOC) measurement but also interacted with the DAX-8 resin. By comparing the apparent molecular weight (aMW) distribution of untreated and pH-adjusted EPS samples, more complete EPS aMW information was preserved at pH 5. Thus, elution at pH 5 was preferred in this study for the qualitative analysis of EPS hydrophobic features. The hydrophobic fraction of EPS retained by the resin at pH 5 was ascribed to a wide aMW range, ranging from >440 to 0.3 kDa. Within this range, EPS molecules ranging from 175 to 31 kDa were mostly retained by the DAX-8 resin, which indicates that these EPS molecules are highly hydrophobic.
KeywordsAnaerobic granular sludge EPS extraction DAX-8 resin Hydrophobicity SEC/absorbance 210 nm
The authors thank the EU for providing financial support through the Erasmus Mundus Joint Doctorate Program ETeCoS3 (Environmental Technologies for Contaminated Solids, Soils and Sediments, grant agreement FPA no. 2010-0009). The authors also thank the Regional Council of Limousin for its financial support, Madam Isabelle Deveaux from the Smurfit Kappa Company (Saillat-sur-Vienne, France) for providing the anaerobic granular sludge, and Dr. Jérôme Labanowski (Université de Poitiers, France) for giving suggestions on the XAD techniques.
Compliance with ethical standards
The authors declare that the research does not contain any studies with human participants or animals.
Conflict of interest
The authors declare that they have no conflict of interest.
- Aiken GR, McKnight DM, Wershaw RL, Mac Carthy P (1985) Humic substances in soil, sediment, and water: geochemistry, isolation, and characterization. Wiley, New YorkGoogle Scholar
- Behrens C, Hartmann K, Sunderhaus S, Braun HP, Eubel H (2013) Approximate calculation and experimental derivation of native isoelectric points of membrane protein complexes of Arabidopsis chloroplasts and mitochondria. Biochim Biophys Acta BBA—Biomembr 1828:1036–1046. doi: 10.1016/j.bbamem.2012.11.028
- Bhatia D, Bourven I, Simon S, Bordas F, van Hullebusch ED, Rossano S, Lens PNL, Guibaud G (2013) Fluorescence detection to determine proteins and humic-like substances fingerprints of exopolymeric substances (EPS) from biological sludges performed by size exclusion chromatography (SEC). Bioresour Technol 131:159–165. doi: 10.1016/j.biortech.2012.12.078 CrossRefPubMedGoogle Scholar
- Bourven I, Simon S, Bhatia D, van Hullebusch ED, Guibaud G (2015b) Effect of various size exclusion chromatography (SEC) columns on the fingerprints of extracellular polymeric substances (EPS) extracted from biological sludge. J Taiwan Inst Chem Eng 49:148–155. doi: 10.1016/j.jtice.2014.11.025 CrossRefGoogle Scholar
- Braissant O, Decho AW, Dupraz C, Glunk C, Przekop KM, Visscher PT (2007) Exopolymeric substances of sulfate-reducing bacteria: interactions with calcium at alkaline pH and implication for formation of carbonate minerals. Geobiology 5:401–411. doi: 10.1111/j.1472-4669.2007.00117.x CrossRefGoogle Scholar
- Brown W, Iverson B, Anslyn E, Foote C (2013) Organic chemistry. Cengage Learning, BelmontGoogle Scholar
- Comte S, Guibaud G, Baudu M (2006a) Relations between extraction protocols for activated sludge extracellular polymeric substances (EPS) and complexation properties of Pb and Cd with EPS: part II. Consequences of EPS extraction methods on Pb2+ and Cd2+ complexation. Enzyme MicrobTechnol 38:246–252. doi: 10.1016/j.enzmictec.2005.06.023 CrossRefGoogle Scholar
- Comte S, Guibaud G, Baudu M (2006b) Relations between extraction protocols for activated sludge extracellular polymeric substances (EPS) and EPS complexation properties: part I. Comparison of the efficiency of eight EPS extraction methods. Enzyme MicrobTechnol 38:237–245. doi: 10.1016/j.enzmictec.2005.06.016 CrossRefGoogle Scholar
- d’Abzac P, Bordas F, van Hullebusch ED, Lens PNL, Guibaud G (2010) Extraction of extracellular polymeric substances (EPS) from anaerobic granular sludges: comparison of chemical and physical extraction protocols. Appl Microbiol Biotechnol 85:1589–1599. doi: 10.1007/s00253-009-2288-x CrossRefPubMedGoogle Scholar
- Ding Y, Tian Y, Li Z, Zuo W, Zhang J (2015) A comprehensive study into fouling properties of extracellular polymeric substance (EPS) extracted from bulk sludge and cake sludge in a mesophilic anaerobic membrane bioreactor. BioresourTechnol 192:105–114. doi: 10.1016/j.biortech.2015.05.067 CrossRefGoogle Scholar
- Forster CF, Clarke AR (1983) The production of polymer from activated sludge by ethanolic extraction and its relation to treatment plant operation. Water Pollut Control 82:430–433Google Scholar
- Lin H, Zhang M, Wang F, Meng F, Liao BQ, Hong H, Chen J, Gao W (2014) A critical review of extracellular polymeric substances (EPSs) in membrane bioreactors: characteristics, roles in membrane fouling and control strategies. J Membr Sci 460:110–125. doi: 10.1016/j.memsci.2014.02.034 CrossRefGoogle Scholar
- Moran AP (2009) Microbial glycobiology: structures, relevance and applications. Elsevier, OxfordGoogle Scholar
- Petsko GA, Ringe D (2008) Protein structure and function. Oxford university Press, Sunderland, MAGoogle Scholar
- Rättö M, Verhoef R, Suihko ML, Blanco A, Schols HA, Voragen AGJ, Wilting R, Siika-aho M, Buchert J (2006) Colanic acid is an exopolysaccharide common to many enterobacteria isolated from paper-machine slimes. J Ind Microbiol Biotechnol 33:359–367. doi: 10.1007/s10295-005-0064-1 CrossRefPubMedGoogle Scholar
- Rozgonyi F, Szitha KR, Ljungh Å, Baloda SB, Hjertén S, Wadström T (1985) Improvement of the salt aggregation test to study bacterial cell-surface hydrophobicity. FEMS Microbiol Lett 30:131–138.Google Scholar
- Simon S, Païro B, Villain M, d’Abzac P, van Hullebusch ED, Lens PNL, Guibaud G (2009) Evaluation of size exclusion chromatography (SEC) for the characterization of extracellular polymeric substances (EPS) in anaerobic granular sludges. Bioresour Technol 100:6258–6268. doi: 10.1016/j.biortech.2009.07.013 CrossRefPubMedGoogle Scholar
- Villain M, Simon S, Bourven I, Guibaud G (2010) The use of a new mobile phase, with no multivalent cation binding properties, to differentiate extracellular polymeric substances (EPS), by size exclusion chromatography (SEC), from biomass used for wastewater treatment. Process Biochem 45:1415–1421. doi: 10.1016/j.procbio.2010.05.018 CrossRefGoogle Scholar
- Zhang P, Fang F, Chen YP, Shen Y, Zhang W, Yang JX, Li C, Guo JS, Liu SY, Huang Y, Li S, Gao X, Yan P (2014) Composition of EPS fractions from suspended sludge and biofilm and their roles in microbial cell aggregation. Chemosphere 117:59–65. doi: 10.1016/j.chemosphere.2014.05.070 CrossRefPubMedGoogle Scholar