title: Variations of both bacterial community and extracellular polymers: the inducements of increase of cell hydrophobicity from biofloc to aerobic granule sludge.
abstract: To investigate the inducements of increase of cell hydrophobicity from aerobic biofloc (ABF) and granular sludge (AGS), in this study, as the first time the hydrophilic and hydrophobic bacterial communities were analyzed independently. Meanwhile, the effect of extracellular polymers (EPS) on the cell hydrophobicity is also studied. Few Bacteroidetes were detected (1.35% in ABF and 3.84% in AGS) in hydrophilic bacteria, whereas they are abundant in the hydrophobic cells (47.8% and 43% for ABF and AGS, respectively). The main species of Bacteroidetes changed from class Sphingobacteria to Flavobacteria in AGS. On the other hand, EPS is directly responsible to cell hydrophobicity. For AGS, cell hydrophobicity was sharply decreased after EPS extraction. Both quantity and property of the extracellular protein are related to hydrophobicity. Our results showed the variation of cell hydrophobicity was resulted from variations of both bacterial population and EPS.
authors.affiliation: Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Guo
authors.forename: Sheng-Hua
authors.initials: SH
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Yu
authors.forename: Bo
authors.initials: B
authors.lastname: Wei
mesh_terms: D000332:Aerobiosis; D001419:Bacteria / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D001704:Biopolymers / Q000378:metabolism*; D004275:DNA, Ribosomal / Q000235:genetics; D005110:Extracellular Space / Q000378:metabolism*; D005427:Flocculation; D005453:Fluorescence; D015723:Gene Library; D057927:Hydrophobic and Hydrophilic Interactions; D008969:Molecular Sequence Data; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors
chemical_list: D001704:Biopolymers; D004275:DNA, Ribosomal; D012722:Sewage