title: Exploring the potential of iTRAQ proteomics for tracking the transformation of extracellular proteins from enzyme-disintegrated waste activated sludge.
abstract: To characterize the transformation of extracellular proteins extracted from raw and enzyme-disintegrated waste activated sludge (WAS), extracts of extracellular polymeric substances (EPS) were subject to isobaric tags for relative and absolute quantitation (iTRAQ) proteomics analysis. 209 proteins were identified and categorized into three Gene Ontology classifications: "cellular components", "molecular function", and "biological processes". Most identified proteins originated from intracellular components, organelles, or cytoplasm, suggesting that cell decline and lysis represent the main sources of extracellular proteins in WAS. The major protein functions comprised "transporter binding activity", "macromolecule metabolic process", and "biosynthesis enzyme catalytic activity". In total, 15 proteins categorized as "membrane part" and "biological adhesion" and 10 as "organelle" were down- or up-regulated, respectively, implying that the enzyme-disintegration mainly induced WAS floc-structure disintegration via membrane structure and corresponding biological adhesion disruption. The proteomics study will provide valuable clues to better understand EPS changes associated with enzymatic treatment at molecular levels.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Boran
authors.initials: B
authors.lastname: Wu
authors.affiliation: Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, 8 Jiangwangmiao Street, Nanjing 210042, China.
authors.forename: Lianghu
authors.initials: L
authors.lastname: Su
authors.affiliation: Environmental Microbiology and Ecology Research Center, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science (CAS), 266 Fangzheng Avenue, Chongqing 400714, China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Song
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China. Electronic address: xlchai@tongji.edu.cn.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Chai
mesh_terms: D016000:Cluster Analysis; D005110:Extracellular Space / Q000737:chemistry*; D007553:Isotope Labeling / Q000379:methods*; D010447:Peptide Hydrolases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid
chemical_list: D011506:Proteins; D012722:Sewage; D010447:Peptide Hydrolases
keywords: Extracellular polymeric substances (EPS); Proteomics; Waste activated sludge; iTRAQ