Adsorption of several actinide (Th, U) and lanthanide (La, Eu, Yb) ions by Mycobacterium smegmatis

Autor: H. J. MacCordick, J. C. Hubert, Yves Andres
Rok vydání: 1993
Předmět:
Zdroj: Applied Microbiology and Biotechnology. 39
ISSN: 1432-0614
0175-7598
DOI: 10.1007/bf00192103
Popis: Adsorption measurements of several actinide [thorium (Th), uranium (U)] and lanthanide [lanthanum (La), europium (Eu), ytterbium (Yb)] cations by Mycobacterium smegmatis showed that sorption kinetics followed a three-phase pattern. For 5% (w/w) bacterial suspensions at pH 1, maximum cation biosorption per gram dry biomass corresponded to 170 μmol Th4+ and 187 μmol UOinf2sup2+. Adsorption of all cations studied obeyed the Brunauer-Emmett-Teller isotherm, which assumes multilayer binding at constant energy. Plots for the Scatchard model showed the existence of at least two types of cation complexation site, with strong and weak affinity and negative cooperation. Th4+ was preferentially adsorbed with respect to the other cations, although all species appeared to compete for the same sites independently of bacterial viability. Adsorption of these cations was accompanied by partial release of magnesium from the cell wall, indicating that exchange reactions occurred at magnesium (Mg)-bonding sites.
Databáze: OpenAIRE
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