title: Role of extracellular polymeric substances in Cu(II) adsorption on Bacillus subtilis and Pseudomonas putida.
abstract: The effect of extracellular polymeric substances (EPS) of Gram-positive Bacillus subtilis and Gram-negative Pseudomonas putida on Cu(II) adsorption was investigated using a combination of batch adsorption, potentiometric titrations, Fourier transform infrared spectroscopy. Both the potentiometric titrations and the Cu(II) adsorption experiments indicated that the presence of EPS in a biomass sample significantly enhance Cu(II) adsorption capacity. Surface complexation modeling showed that the pKa values for the three functional groups (carboxyl, phosphate and hydroxyl) were very similar for untreated and EPS-free cells, indicating no qualitative difference in composition. However, site concentrations on the untreated cell surface were found to be significantly higher than those on the EPS-free cell surface. Infrared analysis provided supporting evidence and demonstrated that carboxyl and phosphate groups are responsible for Cu(II) adsorption on the native and EPS-free cells.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Linchuan
authors.initials: L
authors.lastname: Fang
authors.forename: Xing
authors.initials: X
authors.lastname: Wei
authors.forename: Peng
authors.initials: P
authors.lastname: Cai
authors.forename: Qiaoyun
authors.initials: Q
authors.lastname: Huang
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Liang
authors.forename: Xinming
authors.initials: X
authors.lastname: Rong
mesh_terms: D000327:Adsorption; D001412:Bacillus subtilis / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D001704:Biopolymers / Q000378:metabolism*; D003300:Copper / Q000302:isolation & purification*; D005110:Extracellular Space / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D011199:Potentiometry; D016958:Pseudomonas putida / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D001704:Biopolymers; D012996:Solutions; D003300:Copper