Savvaidis Ioannis, Hughes Martin N, Poole Robert K
Section of Industrial and Food Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
Antonie Van Leeuwenhoek. 2003;84(2):99-107. doi: 10.1023/a:1025489915704.
The technique of differential pulse polarography is shown here to be applicable to the monitoring directly the biosorption of metal ions from solution by live bacteria from mixed metal solutions. Biosorption of Cd(II), Zn(II) and Ni(II) by P. cepacia was followed using data obtained at the potential which is characteristic of the metal ion in the absence and presence of cells. Hepes buffer (pH 7.4, 50 mM) was used as a supporting electrolyte in the polarographic chamber and metal ion peaks in the presence of cells of lower amplitude were obtained due to metal-binding by the cells. Well defined polarographic peaks were obtained in experiments involving mixtures of metal ions of Cd(II)-Zn(II), Cu(II)-Zn(II), Cu(II)-Cd(II) and Cd(II)-Ni(II). Biosorption of Cd(II), Zn(II) increased with solution pH. The method was also tested as a rapid technique for assessing removal of metal ions by live bacteria and the ability of the polarographic technique in measuring biosorption of metal ions from mixed metal solutions is demonstrated. Cu(II) was preferentially bound and removal of metals was in the order Cu(II) > Ni(II) > Zn(II), Cd(II) by intact cells of P. cepacia.
差分脉冲极谱法在此被证明适用于直接监测混合金属溶液中的活细菌对溶液中金属离子的生物吸附。利用在无细胞和有细胞存在时金属离子的特征电位下获得的数据，跟踪洋葱伯克霍尔德菌对Cd(II)、Zn(II)和Ni(II)的生物吸附。在极谱池中使用Hepes缓冲液（pH 7.4，50 mM）作为支持电解质，由于细胞对金属的结合，在有细胞存在时获得了幅度较低的金属离子峰。在涉及Cd(II)-Zn(II)、Cu(II)-Zn(II)、Cu(II)-Cd(II)和Cd(II)-Ni(II)金属离子混合物的实验中获得了明确的极谱峰。Cd(II)、Zn(II)的生物吸附随溶液pH值的增加而增加。该方法还作为一种评估活细菌去除金属离子的快速技术进行了测试，并证明了极谱技术测量混合金属溶液中金属离子生物吸附的能力。洋葱伯克霍尔德菌的完整细胞优先结合Cu(II)，金属去除顺序为Cu(II) > Ni(II) > Zn(II)，Cd(II)。
