Composition of EPS fractions from suspended sludge and biofilm and their roles in microbial cell aggregation

Peng Zhang; Fang Fang; You-Peng Chen; Yu Shen; Wei Zhang; Ji-Xiang Yang; Chun Li; Jin-Song Guo; Shao-Yang Liu; Yang Huang; Shan Li; Xu Gao; Peng Yan

doi:10.1016/j.chemosphere.2014.05.070

Composition of EPS fractions from suspended sludge and biofilm and their roles in microbial cell aggregation

Chemosphere. 2014 Dec:117:59-65. doi: 10.1016/j.chemosphere.2014.05.070. Epub 2014 Jun 24.

Authors

Peng Zhang¹, Fang Fang¹, You-Peng Chen², Yu Shen³, Wei Zhang³, Ji-Xiang Yang³, Chun Li¹, Jin-Song Guo⁴, Shao-Yang Liu⁵, Yang Huang¹, Shan Li¹, Xu Gao¹, Peng Yan³

Affiliations

¹ Key Laboratory of Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China.
² 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.
³ Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
⁴ 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.
⁵ Department of Chemistry and Physics, Troy University, Troy, AL 36082, USA.

PMID: 24968163
DOI: 10.1016/j.chemosphere.2014.05.070

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.

Keywords: Aggregation; Biofilm; Extracellular polymeric substances; Raman; Suspended sludge.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacterial Adhesion*
Biofilms / growth & development*
Biopolymers / chemistry*
Flocculation
Hydrophobic and Hydrophilic Interactions
Sewage* / chemistry
Sewage* / microbiology
Spectrometry, Fluorescence
Spectrum Analysis, Raman
Surface Properties

Substances

Biopolymers
Sewage