Bioaccumulation of nickel from aqueous solutions by genetically engineered Escherichia coli.
This study constructed a genetically engineered Escherichia coli JM109 which simultaneously expressed nickel transport system and metallothionein to remove and recover Ni(2+) from aqueous solution. Bioaccumulation process was rapid and followed linearized Langmuir isotherm. A more than six-fold increase of Ni(2+) binding capacity was obtained by genetically engineered E. coli cells compared with original host E. coli cells. A pH assay showed genetically engineered E. coli cells accumulated Ni(2+) effectively over a broad range of pH (4-10). The presence of 1000 mg/L Na(+) and Ca(2+), or 50mg/L Cd(2+) or Pb(2+) did not have a significant effect on Ni(2+) bioaccumulation, while Mg(2+), Hg(2+) and Cu(2+) posed a severe adverse influence on Ni(2+) uptake by genetically engineered E. coli. Furthermore, genetically engineered E. coli cells did not require extra nutrients for Ni(2+) bioaccumulation.
Department of Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China. xdeng@jingxian.xmu.edu.cn
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D001673:Biodegradation, Environmental; D004926:Escherichia coli / Q000737:chemistry* / Q000235:genetics*; D005818:Genetic Engineering; D006863:Hydrogen-Ion Concentration; D008668:Metallothionein / Q000235:genetics* / Q000494:pharmacology; D009532:Nickel / Q000493:pharmacokinetics*; D013696:Temperature; D018508:Water Purification / Q000379:methods*
D009532:Nickel; D008668:Metallothionein