| Summary: | Twelve cadmium native bacteria previously isolated in soils of cocoa farms located in
the western Colombian Andes (Santander), and tolerant to 2500 M CdCl2 (120 mg Cd/L), were
chosen in order to test their tolerance and Cd immobilization using liquid culture medium (Nutritive
broth) at different concentrations of heavy metals. Furthermore, in the greenhouse experiments, the
strains Exiguobacterium sp. (11-4A), Klebsiella variicola sp. (18-4B), and Enterobacter sp. (29-4B) were
applied in combined treatments using CCN51 cacao genotype seeds grown in soil with different
concentrations of Cd. All bacterial strains’ cell morphologies were deformed in TEM pictures, which
also identified six strain interactions with biosorption and four strain capacities for bioaccumulation;
FT-IR suggested that the amide, carbonyl, hydroxyl, ethyl, and phosphate groups on the bacteria
biomass were the main Cd binding sites. In the pot experiments, the concentration of Cd was
distributed throughout the cacao plant, but certain degrees of immobilization of Cd can occur in soil
to prevent an increase in this level in roots with the presence of Klebsiella sp.
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