title: Characterization of extracellular polymeric substances in the biofilms of typical bacteria by the sulfur K-edge XANES spectroscopy.
abstract: A combined approach of physicochemical extraction and sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy was applied to characterize the extracellular polymeric substances (EPS) of typical bacterial biofilms in this study. Physicochemical analysis showed variation of the contents of DNA, polysaccharide and protein in different fractions of EPS in different mediums. The sulfur K-edge XANES analysis yielded a variety of spectra. Spectral fitting of the XANES spectra utilizing a large set of model compounds showed that there was more reduced sulfur in both LB-EPS (loosely bound EPS) and TB-EPS (tightly bound EPS) of all the biofilms in LB medium than in R2A medium. More oxidized sulfur was identified in LB-EPS than that in TB-EPS, suggesting different niches and physiological heterogeneity in the biofilms. Our results suggested that the sulfur K-edge XANES can be a useful tool to analyze the sulfur speciation in EPS of biofilms.
authors.affiliation: Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China. Electronic address: hrlin@iue.ac.cn.
authors.forename: Huirong
authors.initials: H
authors.lastname: Lin
authors.affiliation: Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China.
authors.forename: Chengsong
authors.initials: C
authors.lastname: Ye
authors.affiliation: Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Lv
authors.affiliation: Beijing No. 4 High School, Beijing 100034, China.
authors.forename: Clark Renjun
authors.initials: CR
authors.lastname: Zheng
authors.affiliation: Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China.
authors.forename: Shenghua
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Institute of High Energy Physics, Chinese Academy of Science, Beijing Synchrotron Radiation Facility, Beijing 100049, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Institute of High Energy Physics, Chinese Academy of Science, Beijing Synchrotron Radiation Facility, Beijing 100049, China.
authors.forename: Yidong
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China. Electronic address: xyu@iue.ac.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Yu
mesh_terms: D001419:Bacteria / Q000737:chemistry* / Q000145:classification / Q000378:metabolism*; D018441:Biofilms; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D013455:Sulfur / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy / Q000379:methods*
chemical_list: D011108:Polymers; D013455:Sulfur
keywords: Biofilms; Characterization; EPS; Sulfur; XANES