Open AccessCadmium biosorption properties of the metal‐resistant Ochrobactrum cytisi Azn6.2
Author(s) -
RodríguezLlorente Ignacio D.,
Gamane Djamila,
Lafuente Alejandro,
Dary Mohammed,
El Hamdaoui Abdelaziz,
Delgadillo Julián,
Doukkali Bouchra,
Caviedes Miguel A.,
Pajuelo Eloísa
Publication year - 2010
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.200900060
Subject(s) - biosorption , cadmium , desorption , chemistry , nuclear chemistry , metal , pellets , metal ions in aqueous solution , adsorption , materials science , sorption , organic chemistry , composite material
The aim of this work was to establish the conditions for using Ochrobactrum cytisi Azn6.2 as a metal biosorbent. Azn6.2 is a novel strain from the legume symbiont O. cytisi that has been isolated from nodules of Medicago polymorpha plants grown on heavy metal‐polluted soils. Compared with the strain ESC1, Azn6.2 showed some biochemical differences, as well as antibiotic susceptibility, Azn6.2 was multi‐resistant to heavy metals, such as Cu, Cd and Zn, and bacterial pellets were able to biosorb high amounts of Cd and Zn. As shown by scanning electron microscopy coupled to energy dispersive X‐ray, most of Cd was attached to the cell surface. Optimal conditions for Cd biosorption were established, being 1 mM Cd ions in solution and 2 h of contact with the biosorbent at room temperature. At these conditions, maximal Cd loading capacity reached 32–34 mg/g. Cd desorption from bacterial pellets was achieved after washing with EDTA or, at higher efficiency, at pH 1.0. These results indicated that biosorption/desorption on O. cytisi Azn6.2 biomass should be a cost‐effective method for Cd recovery from contaminated solutions.