Microbial heap bioleaching is being used as an industrial process to recover copper from
low grade ores. It is known that a consortium of different microorganisms participates in this
process. Therefore identification and quantification of communities inhabiting heap bioleaching
operations is a key step for understanding the dynamics and role of these microorganisms in the
process. A quantitative real-time PCR approach was used to investigate the microbial dynamics in
this process. To study the microbial population inhabiting a low-grade copper sulphide ore
bioleaching industrial heap process at Escondida Mine in Chile, 16S rRNA genetic libraries were
constructed using bacterial and archaeal universal primers. Phylogenetic analyses of sequences
retrieved from genetic libraries showed that the community is mainly composed by microoganisms
related to Acidithiobacillus ferrooxidans (2 strains), Acidithiobacillus thiooxidans, Leptospirillum
ferrooxidans, Leptospirillum ferriphilum and the archaea Ferroplasma.
Specific primers for real-time PCR determination were designed and tested to amplify each of
the sequences obtained by cloning. Standard curves for real time PCR were performed using
plasmid DNA from selected clones. This methodology is actually being used to monitor relevant
microorganisms inhabiting this low-grade copper sulphide ore bioleaching industrial heap.
Evaporitic brines and copper-sulphide ore genesis at Jbel Haïmer (Central Jebilet, Morocco)
