A Case of Predominance of Alicyclobacillus tolerans in Microbial Community during Bioleaching of Pentlandite-Chalcopyrite Concentrate

Bacterial isolates assigned to the species Alicyclobacillus tolerans, which occupies an intermediate position between organotrophic genus and mixotrophic Sulfobacillus, were revealed as members of acidophilic chemolithotrophic community during stirred-tank bioleaching violarite–pentlandite–chalcopyrite concentrate at 40 °C. Surprisingly, this succeeded more common iron-oxidizing after a series processes in bioreactors. The possibility organoheterotrophic growth Al. tolerance low pH values (1.0–1.15), well preservation cells via sporulation under unfavorable conditions, may explain its key role copper–nickel bulk concentrate. Isolation two other sulfur-oxidizing pure cultures dominating microbial community, together with their phylogenetic characterization, allowed assignment these Acidithiobacillus caldus. This studies communities are important for development intensification processes, including biobeneficiation approach previously proposed by us.