title: Composition of EPS fractions from suspended sludge and biofilm and their roles in microbial cell aggregation.
abstract: The adhesion and aggregation properties of microbial cell are closely related to extracellular polymeric substances (EPS). In this work, the composition and physicochemical characteristics of EPS in biofilm and suspended sludge (S-sludge) were determined to evaluate their roles in microbial cell aggregation. Raman spectroscopy and three-dimensional fluorescence spectra have been employed to reveal each EPS fraction in different composition. The flocculating capacity of each EPS fraction in the S-sludge shows extraordinary activity, comparing its counterpart in biofilm. Microbial cell surfaces present high hydrophobicity and increased zeta potentials upon EPS extraction. In addition, the respective contribution of EPS to cell aggregating was elucidated. The contribution of combined SEPS and LB-EPS was 23% for S-sludge sample, whereas that was negligible for biofilm sample. The contribution of LB-EPS and TB-EPS were 16% and 30% for S-sludge sample, and -6% and negligible for biofilm sample, respectively. Therefore, EPS promoted the S-sludge cells to aggregate, while in contrast, they showed a negligible or negative effect on the biofilm cells aggregating.
authors: Key Laboratory of Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China.
authors: Peng
authors: P
authors: Zhang
authors: Key Laboratory of Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China.
authors: Fang
authors: F
authors: Fang
authors: Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China. Electronic address: ypchen@cigit.ac.cn.
authors: You-Peng
authors: YP
authors: Chen
authors: Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
authors: Yu
authors: Y
authors: Shen
authors: Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
authors: Wei
authors: W
authors: Zhang
authors: Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
authors: Ji-Xiang
authors: JX
authors: Yang
authors: Key Laboratory of Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China.
authors: Chun
authors: C
authors: Li
authors: Key Laboratory of Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China; Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China. Electronic address: guojs@cigit.ac.cn.
authors: Jin-Song
authors: JS
authors: Guo
authors: Department of Chemistry and Physics, Troy University, Troy, AL 36082, USA.
authors: Shao-Yang
authors: SY
authors: Liu
authors: Key Laboratory of Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China.
authors: Yang
authors: Y
authors: Huang
authors: Key Laboratory of Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China.
authors: Shan
authors: S
authors: Li
authors: Key Laboratory of Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China.
authors: Xu
authors: X
authors: Gao
authors: Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
authors: Peng
authors: P
authors: Yan
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D001704:Biopolymers / Q000737:chemistry*; D005427:Flocculation; D057927:Hydrophobic and Hydrophilic Interactions; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D013050:Spectrometry, Fluorescence; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D001704:Biopolymers; D012722:Sewage
keywords: Aggregation; Biofilm; Extracellular polymeric substances; Raman; Suspended sludge