title: Hydrophobic features of EPS extracted from anaerobic granular sludge: an investigation based on DAX-8 resin fractionation and size exclusion chromatography.
abstract: 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.
authors.affiliation: Laboratoire Géomatériaux et Environnement (EA 4508), Université Paris-Est, UPEM, 77454, Marne-la-Vallée, France.|Groupement de Recherche Eau Sol Environnement (EA 4330), Faculté des Sciences et Techniques, Université de Limoges, 123 Avenue A. Thomas, 87060, Limoges Cedex, France.|UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands.
authors.forename: Feishu
authors.initials: F
authors.lastname: Cao
authors.affiliation: Groupement de Recherche Eau Sol Environnement (EA 4330), Faculté des Sciences et Techniques, Université de Limoges, 123 Avenue A. Thomas, 87060, Limoges Cedex, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Bourven
authors.affiliation: UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands.
authors.forename: Piet N L
authors.initials: PNL
authors.lastname: Lens
authors.affiliation: Laboratoire Géomatériaux et Environnement (EA 4508), Université Paris-Est, UPEM, 77454, Marne-la-Vallée, France.|UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands.
authors.forename: Eric D
authors.initials: ED
authors.lastname: van Hullebusch
authors.affiliation: Laboratoire Géomatériaux et Environnement (EA 4508), Université Paris-Est, UPEM, 77454, Marne-la-Vallée, France.
authors.forename: Yoan
authors.initials: Y
authors.lastname: Pechaud
authors.affiliation: Groupement de Recherche Eau Sol Environnement (EA 4330), Faculté des Sciences et Techniques, Université de Limoges, 123 Avenue A. Thomas, 87060, Limoges Cedex, France. gilles.guibaud@unilim.fr.
authors.forename: Gilles
authors.initials: G
authors.lastname: Guibaud
mesh_terms: D000693:Anaerobiosis; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry* / Q000302:isolation & purification; D012722:Sewage / Q000737:chemistry*
chemical_list: D011108:Polymers; D012722:Sewage
keywords: Anaerobic granular sludge; DAX-8 resin; EPS extraction; Hydrophobicity; SEC/absorbance 210 nm