Relationships between galvanic interaction, copper extraction and community dynamics during bioleaching of chalcopyrite by a moderately thermophilic culture

A moderately thermophilic culture was enriched and adapted to bioleach chalcopyrite at high pulp density. In order to further improve copper extraction, effects of galvanic interaction on bioleaching performance and community dynamics were investigated by adding pyrite. Copper extractions were improved by 2.91 and 1.97 times in the initial and the final stages when pyrite was present, respectively. However, it did not benefit chalcopyrite dissolution in the middle stage. Community dynamics analysis showed that succession of the attached cells was significantly different from community dynamics of the planktonic cells. One of planktonic populations always dominated the communities in most cases, while no species had absolutely competitive advantages in the attached communities. In addition, the presence of pyrite had significant effects on planktonic and attached community structures, and could accelerate planktonic community succession.