title: Influences of copper speciation on toxicity to microorganisms in soils.
abstract: OBJECTIVE
  To investigate the relationship between copper speciation and microbial features (microbial communities and copper tolerance level) in order to determine the adverse effect of different forms of Cu on microorganisms.
  
  
  METHODS
  Tessier's sequential extraction procedure was used to qualify the different Cu forms (exchangeable, carbonate bound, Fe/Mn oxide bound, residue and organic matter bound), and the copper tolerance level (expressed as IC50, influence concentration) was measured by the plate-count method.
  
  
  RESULTS
  By simple correlation analysis, the IC50 was positively correlated with the concentration of exchangeable Cu (R2 = 0.8204), while weakly correlated with other forms of Cu.
  
  
  CONCLUSIONS
  The bacterial community tolerance increases in the copper-contaminated soil while sensitive bacteria decrease in the copper-contaminated soils. The exchangeable Cu exerts high toxicity to microbial communities.
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. sunshujuan@mail.nankai.edu.cn
authors.forename: Shu-Juan
authors.initials: SJ
authors.lastname: Sun
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.forename: Shu-Gui
authors.initials: SG
authors.lastname: Dai
authors.forename: Xue
authors.initials: X
authors.lastname: Han
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D002681:China; D003300:Copper / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D004784:Environmental Monitoring; D005658:Fungi / Q000187:drug effects* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity*
chemical_list: D012989:Soil Pollutants; D003300:Copper