Dynamic of active microorganisms inhabiting a bioleaching industrial heap of low-grade copper sulfide ore monitored by real-time PCR and oligonucleotide prokaryotic acidophile microarray.
Bottom Line: The active microorganisms in the leaching system were determined using two RNA-based sensitive techniques.However, the prokaryotic acidophile microarray (PAM) analysis showed active members of Alphaproteobacteria in all samples and of Sulfobacillus genus in older ones.Also, new active groups such as Actinobacteria and Acidobacterium genus were detected by PAM.
Affiliation: Biotechnology Center, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta, Chile. Biotecnor Ltda., Antofagasta, Chile.Show MeSH
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Mentions: The microorganisms inhabiting the heap throughout the leaching cycle are mainly bacterial species and reached total 16S rRNA gene copy numbers greater than 107 copies ml−1 and, in general, this value decreased around one order of magnitude in most of the strips when these aged more than 200 days (Fig. 2A and B; all other strips: data not shown). At. ferrooxidans phylotypes were the most abundant microorganisms during the first part of the leaching cycle (around 200 days of operation) and specifically At. ferrooxidans D2 reached around of 107 copies ml−1 during this period (Fig. 2A and B). These 16S rRNA gene copy numbers have been observed in all strips during the first month of operation (Remonsellez et al., 2007; Galleguillos et al., 2008; data not shown). At. ferrooxidans DM reached between 105 and 106 copies ml−1 in most of the strips (Fig. 2A and B and Table 3; all other strips: data not shown). In marked contrast, L. ferriphilum phylotypes were present with lower abundance (between 102 and 103 copies ml−1) during the first month of operation in all strips, but copy numbers of both Leptospirillum phylotypes, increased with age reaching around of 105 copies ml−1 (Fig. 2A and B and Table 3; all other strips: data not shown). The sulfur‐oxidizer At. thiooxidans maintained a constant copy numbers (105 copies ml−1) throughout the leaching cycle in all strips (Fig. 2A and B and Table 3; most of other strips: data not shown). The last microorganism has been identified from other heap operations (Goebel and Stackebrandt, 1994; Espejo and Romero, 1997), but its dynamic had not been reported until this study.
Affiliation: Biotechnology Center, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta, Chile. Biotecnor Ltda., Antofagasta, Chile.