Identification of microorganisms at different times in a bioleaching process for the recovery of gold and silver from minerals in oxide form
Cuauhtémoc Contreras Mora,
Juan Antonio Rojas Contreras,
Mayra Cristina Rosales Villarreal,
José Luis Urban Martínez,
Efren Delgado,
Hiram Medrano Roldan,
Felipe Samuel Hernández Rodarte,
Damián Reyes Jáquez
Affiliations
Cuauhtémoc Contreras Mora
Department of Chemical and Biochemical Engineering, National Technological Institute of Mexico (TecNM), Durango Institute of Technology (ITD), Felipe Pescador 1830 Ote. Col, Nueva Vizcaya, Durango, Dgo, 34080, Mexico
Juan Antonio Rojas Contreras
Department of Chemical and Biochemical Engineering, National Technological Institute of Mexico (TecNM), Durango Institute of Technology (ITD), Felipe Pescador 1830 Ote. Col, Nueva Vizcaya, Durango, Dgo, 34080, Mexico
Mayra Cristina Rosales Villarreal
Department of Chemical and Biochemical Engineering, National Technological Institute of Mexico (TecNM), Durango Institute of Technology (ITD), Felipe Pescador 1830 Ote. Col, Nueva Vizcaya, Durango, Dgo, 34080, Mexico
José Luis Urban Martínez
Department of Chemical and Biochemical Engineering, National Technological Institute of Mexico (TecNM), Durango Institute of Technology (ITD), Felipe Pescador 1830 Ote. Col, Nueva Vizcaya, Durango, Dgo, 34080, Mexico
Efren Delgado
Food Science and Technology, Department of Family and Consumer Sciences, New Mexico State University, P.O. Box 30001, Las Cruces, NM, 88003-8001, USA
Hiram Medrano Roldan
Department of Chemical and Biochemical Engineering, National Technological Institute of Mexico (TecNM), Durango Institute of Technology (ITD), Felipe Pescador 1830 Ote. Col, Nueva Vizcaya, Durango, Dgo, 34080, Mexico
Felipe Samuel Hernández Rodarte
Department of Chemical and Biochemical Engineering, National Technological Institute of Mexico (TecNM), Durango Institute of Technology (ITD), Felipe Pescador 1830 Ote. Col, Nueva Vizcaya, Durango, Dgo, 34080, Mexico
Damián Reyes Jáquez
Department of Chemical and Biochemical Engineering, National Technological Institute of Mexico (TecNM), Durango Institute of Technology (ITD), Felipe Pescador 1830 Ote. Col, Nueva Vizcaya, Durango, Dgo, 34080, Mexico; Corresponding author.
In this study, gold and silver were recovered through a bioleaching process conducted at room temperature over 11 days. Native bacteria and varying ratios of mineral pulp to culture medium (20/80, 37.5/62.5, and 50/50 %) from a mining operation in Zacatecas, Mexico, were evaluated. The mineral was crushed to a particle size of 0.125 inches or smaller, containing gold and silver concentrations of 0.609 g/ton and 138.89 g/ton, respectively. Four native microorganisms were identified using molecular biology techniques and a 16S rRNA gene fragment: Acidovorax citrulli, Brevundimonas albigilva, Sphingomonas korenensis, and Methylobacterium organophilum. The bioleaching system achieved metal extractions of 84.12 % and 63.93 % for gold and silver, respectively. Different microorganisms were identified at various processing times: Sphingomonas korenensis (days 1, 2, 5, 8, and 11), Methylobacterium organophilum (days 1 and 2), Paenibacillus dongdonensis (days 1 and 2), Brevundimonas albigilva (day 5), Ureibacillus manganicus (day 5), Peribacillus simplex (day 8), Niallia circulans (day 8), Massilia atriviolacea (day 11), and Bacillus licheniformis (day 11). The dominant bacterium throughout the process was Sphingomonas korenensis, which appeared at all stages of the experiment.
