Temporal Dynamics of Genes Involved in Metabolic Pathways of C and N of L. ferriphilum, in the Industrial Bioleaching Process of Escondida Mine, Chile


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The structure of the microbial community inhabiting the copper bioleaching heap at Escondida mine has been systematically monitored since the operation was started up (2006), using biomolecular and microbiological analyses. Recent molecular analyses showed that L. ferriphilum was one of the most abundant organisms in the process during year 2012. In order to study the biological dynamics of carbon and nitrogen in the process, the expression levels of thirteen genes of L. ferriphilum were analyzed by RT-qPCR. The 16S rRNA and alaS genes were used as reference, and two relative quantification methods (ΔΔct and and Pffafl) were applied to estimate the relative expression levels of metabolic genes. On the day 110 of operation, a significant increment in the expression level of one gene involved in the cycle of tricarboxilic acids (2-oxoglutarate-acceptor oxidoreductase, oorA) was detected. By other hand, the expression level of two genes involved in carbohydrate metabolism (glgP, Glycogen phosphorilase, and glgA, Glycogen synthase) gradually increased, as the operation time progressed. The expression levels of genes involved in the fixation and assimilation of nitrogen increased at later stages of the process. A significant increase of the expression level of the gene annotated for Nitrogenase iron protein (nifH) was detected on the day 185 of operation. The opposite trend was observed for the gene annotated as Ammonium transporter protein (amt), as an elevated expression level was observed in earlier stages to suddenly decrease on the day 185 of operation, suggesting a change of the nitrogen source. In agreement with molecular quantitative analyses, this work confirmed that L. ferriphilum was an active member of the community during the period studied. This work gives new insights into biological dynamics of carbon and nitrogen, and suggests the potential guidelines to enhance the efficiency of biological components in industrial heap bioleaching processes.



Edited by:

Dr. Nicolas Guiliani, Cecilia Demergasso, Raquel Quatrini, Francisco Remonsellez, Carol Davis-Belmar, Gloria J. Levicán, Pilar Parada, Carlos Barahona and Rebekah Zale




P. A. Galleguillos et al., "Temporal Dynamics of Genes Involved in Metabolic Pathways of C and N of L. ferriphilum, in the Industrial Bioleaching Process of Escondida Mine, Chile", Advanced Materials Research, Vol. 825, pp. 162-165, 2013

Online since:

October 2013




[1] Brierley, C., Bacterial succession in bioheap leaching. Hydrometallurgy, 2001. 59: pp.249-255. Brierley, C. L 2008, How will biomining be applied in future? Transactions of Nonferrous Metals Society of China, 18(6): pp.1302-1310.

DOI: https://doi.org/10.1016/s0304-386x(00)00171-7

[2] Watling, H.R., The bioleaching of sulphide minerals with emphasis on copper sulphides - A review. Hydrometallurgy, 2006. 84(1-2): pp.81-108.

DOI: https://doi.org/10.1016/j.hydromet.2006.05.001

[3] Pizarro, J., et al., Bacterial populations in samples of bioleached copper ore as revealed by analysis of DNA obtained before and after cultivation. Appl Environ Microbiol, 1996. 62(4): pp.1323-8.

[4] Demergasso, C., et al., Molecular characterization of microbial populations in a low-grade copper ore bioleaching test heap. Hydrometallurgy, 2005. 80: pp.241-253.

DOI: https://doi.org/10.1016/j.hydromet.2005.07.013

[5] Brierley, C., Bacterial succession in bioheap leaching. Hydrometallurgy, 2001. 59: pp.249-255.

DOI: https://doi.org/10.1016/s0304-386x(00)00171-7

[6] Demergasso, C., et al. (2011) Scientific monitoring of industrial bioleachong process" in "Biohydrometallurgical Processes: A practical approach, Eds. L. Gonzaga. D. Monteiro, C. Gomes. 90-102.

[7] Rawlings, D.E. and D.B. Johnson, The microbiology of biomining: development and optimization of mineral-oxidizing microbial consortia. Microbiology, 2007. 153: pp.315-324.

DOI: https://doi.org/10.1099/mic.0.2006/001206-0

[8] Galleguillos, P., et al., Identification of differentially expressed genes in an industrial bioleaching heap processing low-grade copper sulphide ore elucidated by RNA arbitrarily primed polymerase chain reaction. Hydrometallurgy, 2008. 94(1-4): pp.148-154.

DOI: https://doi.org/10.1016/j.hydromet.2008.05.031

[9] Leimena, M.M., et al., Comparative analysis of Lactobacillus plantarum WCFS1 transcriptomes by using DNA microarray and next-generation sequencing technologies. Applied and Environmental Microbiology, 2012. 78(12): pp.4141-4148.

DOI: https://doi.org/10.1128/aem.00470-12

[10] Goltsman, D., et al., Community genomic and proteomic analyses of chemoautotrophic iron-oxidizing Leptospirillum rubarum" (Group II) and "Leptospirillum ferrodiazotrophum, (Group III) bacteria in acid mine drainage biofilms. Applied and Environmental Microbiology, 2009. 75(13): pp.4599-4615.

DOI: https://doi.org/10.1128/aem.02943-08

[11] Galleguillos, P.A., K.B. Hallberg, and D.B. Johnson, Microbial diversity and genetic response to stress conditions of extremophilic bacteria isolated from the Escondida copper mine. Advanced Materials research, 2009. 71-73: pp.55-58.

DOI: https://doi.org/10.4028/www.scientific.net/amr.71-73.55

[12] Galleguillos, P., et al., Identification and analysis of diazotrophy in strains of Leptospirillum ferriphilum from heap bioleaching operations. Biohydrometallurgy: Biotech key to unlock Mineral Resources value, Proceedings of the 19th International Biohydrometallurgy Symposium, Changsha, China, September 18-22, 2011, p.1015., (2011).

[13] Winer, J., et al., Development and validation of Real-Time Quantitative Reverse Transcriptase-Polymerase Chain Reaction for monitoring gene expression in cardiac myocytesin vitro. Analytical Biochemistry, 1999. 270(1): pp.41-49.

DOI: https://doi.org/10.1006/abio.1999.4085

[14] Pfaffl, M.W., A new mathematical model for relative quantification in real-time RT-PCR. Nucleic Acids Research, 2001. 29(9): p. e45.

DOI: https://doi.org/10.1093/nar/29.9.e45