Abstract

MEJIA, E. et al. Adaptation of a strain Acidithiobacillus ferrooxidans compatible on concentrates of chalcopyrite (CuFeS₂), sphalerite (ZnS) and galena (PbS). Rev. colomb. biotecnol [online]. 2011, vol.13, n.1, pp.132-143. ISSN 0123-3475.

In this study the adaptation of Acidithiobacillus ferrooxidans-like to high concentrations of chalcopyrite, sphalerite and galena were evaluated with two mineral-particle sizes: 200 and 325 Tyler mesh. The strain was adapted using two simultaneous processes. The first one consisted in a gradual decreasing of the main energy source, ferrous sulphate. The second one consisted in a gradual increasing of the mineral content. Finally, a test was made without ferrous sulphate. The serial subculturing was found to be an efficient strategy to adapt Acidithiobacillus ferrooxidans-like to higher concentrations of chalcopyrite, sphalerite and galena. This indicates that a suitable protocol was employed. The results showed that Acidithiobacillus ferrooxidans-like is more resistant to high concentration of sphalerite, chalcopyrite and galena in descendant order. The particle size played an important role in the adaption of microorganism to the mineral.

Keywords : Sphalerite; chalcopyrite; galena; adapting; Acidithiobacillus ferrooxidans; bioleaching.