GROWTH KINETICS OF ACIDOPHILIC MICROBIAL CONSORTIA IN SUBMERGED CULTURE FOR BIOLEACHING AGENTS

Castillo-Cotrina D.; Chipana-Laura V.; Clavijo-Koc C.; Castellanos-Cabrera R. · Ecologia Aplicada (2024) · DOI: 10.21704/rea.v23i1.2169

Resumen

The study on the bioleaching of metals from minerals is a necessity to improve the process of recovering precious metals and obtaining greater benefits. The objective was to determine in four successive reactivations, the specific growth rate and stability of microbial consortia obtained from the leaching plant of the mining company Southern Cooper Corporation (SCC) in Toquepala, Tacna-Peru. The consortia M-1, M-2, M-5, M-6, and BF-7 were obtained from chalcopyrite from the leach heaps; and the PLS-3, PLS-4, and ILS-8 of the leached liquid solutions. The liquid culture medium used was modified to 9K. The consortia had four successive reactivations in 9K medium, in triplicate, at room temperature for 15 days and with 1vvm aeration. The microbial counts obtained every eight hours in the Petroff-Hausser counting chamber were converted to the decimal logarithmic scale to obtain the growth kinetics using the Malthusian model that determined the rate constant K in the logarithmic phase and the Gompertz model to the microbial growth curve. The consortia from solid samples and biofilm had a faster adaptation, compared to those from the liquid samples of PLS and ILS, which showed an inactive microbial concentration at the beginning. All consortia after the first reactivation showed higher growth rates, the highest being in the PLS-4 consortium during the third reactivation, with a K of 0.025 h-1. The most stable growth rates occurred in the fourth reactivation in the M-6 and BF-7 consortia, these were the most indicated to continue with application studies as inoculum after a third reactivation and achieve the optimization of the bioleaching process of the mineral chalcopyrite. © Departamento Académico de Biología, Universidad Nacional Agraria La Molina, Lima – Perú.

Instituciones: Universidad Nacional Jorge Basadre Grohmann