Adsorption and leaching behaviors of chalcopyrite by two extreme thermophilic archaea
(School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China)
Abstract: The adsorption and leaching of chalcopyrite by two extreme thermophilic archaea (A. brierleyi and S. metallicus) and their mixture were studied. The results revealed that the chalcopyrite leaching rate of S. metallicus was slightly higher than that of A. brierleyi; the mixed system showed the highest rate. Community structure analysis during the leaching process showed that S. metallicus was maintained in a predominant state. However, the proportion of A. brierleyi in the community increased during leaching. Copper concentrations, which increased faster in the mixed system than in the single-organism systems during later stages, was related to the change of A. brierleyi in the community. Langmuir parameter analysis revealed no competitive adsorption between these two thermophilic archaea. Furthermore, qPCR (quantitative polymerase chain reaction) confirmed that adsorption was promoted between A. brierleyi and S. metallicus during mixed leaching. These findings can improve our understanding of the adsorption behaviors of mixed extreme microbial populations on mineral surfaces.
Key words: thermophilic archaea; A. brierleyi; S. metallicus; chalcopyrite; adsorption; leaching