title: Characterization of alginate-like exopolysaccharides isolated from aerobic granular sludge in pilot-plant.
abstract: To understand functional gel-forming exopolysaccharides in aerobic granular sludge, alginate-like exopolysaccharides were specifically extracted from aerobic granular sludge cultivated in a pilot plant treating municipal sewage. The exopolysaccharides were identified by the FAO/WHO alginate identification tests, characterized by biochemical assays, gelation with Ca(2+), blocks fractionation, spectroscopic analysis as UV-visible, FT-IR and MALDI-TOF MS, and electrophoresis. The yield of extractable alginate-like exopolysaccharides was reached 160+/-4mg/g (VSS ratio). They resembled seaweed alginate in UV-visible and MALDI-TOF MS spectra, and distinguished from it in the reactions with acid ferric sulfate, phenol-sulfuric acid and Coomassie brilliant blue G250. Characterized by their high percentage of poly guluronic acid blocks (69.07+/-8.95%), the isolated exopolysaccharides were capable to form rigid, non-deformable gels in CaCl(2). They were one of the dominant exopolysaccharides in aerobic granular sludge. We suggest that polymers play a significant role in providing aerobic granular sludge a highly hydrophobic, compact, strong and elastic structure.
authors.affiliation: Department of Soil and Water Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel. to_zhangmin@vip.sina.com
authors.forename: Yuemei
authors.initials: Y
authors.lastname: Lin
authors.forename: Merle
authors.initials: M
authors.lastname: de Kreuk
authors.forename: M C M
authors.initials: MC
authors.lastname: van Loosdrecht
authors.forename: Avner
authors.initials: A
authors.lastname: Adin
mesh_terms: D000332:Aerobiosis; D000464:Alginates / Q000737:chemistry / Q000302:isolation & purification; D004586:Electrophoresis; D010865:Pilot Projects; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014865:Waste Disposal, Fluid
chemical_list: D000464:Alginates; D011135:Polysaccharides, Bacterial; D012722:Sewage