Abstract

GONZALEZ-CHAVEZ, Ma. del Carmen A et al. Tolerance and Solubilization of Copper by Rhizobacteria Isolated from Sites Polluted by Potentially Toxic Elements. Terra Latinoam [online]. 2009, vol.27, n.1, pp.17-25. ISSN 2395-8030.

This research was developed to contribute to knowledge of environment friendly and low cost biological alternatives for remediation of soils polluted with potentially toxic elements (PTE). The objectives of this study were to determine Cu tolerance in 133 rhizobacteria isolated from plants growing in PTE polluted soils, to evaluate the ability of the most tolerant strains to solubilize metallic Cu and to bioabsorb and bioaccumulate Cu in diluted solutions and metallic Cu. Only 6% of strains were Cu tolerant (3 mM). In the most tolerant strains, Cu content in the medium significantly augmented bacterial biomass. The highest biomass increment (in relation to growth at 0 mM Cu) was found in strains 29 (655%), 101 (457%) and 135 (313%). Strain 95 produced the highest biomass at all tested levels of Cu. Strain 21 had the highest Cu biosorption capacity. Strain 29 significantly bioaccumulated more Cu. The most Cu tolerant strains showed similar metallic Cu solubilization capacity (from 9 to 14 mg). Higher biosorption (44 times) and bioaccumulation (13 times) were observed in the Cu metallic tests than in the diluted solutions.

Keywords : bioaccumulation; biosorption; bioremediation; heavy metals.

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