Isolation and characterization of native strains from lithium-containing mining tailings

Lithium-rich mining tailings create extreme and poorly explored environments that can serve as reservoirs for microorganisms with unique biotechnological potential. In this study, native microorganisms were isolated and molecularly characterized from the tailings of the Nochebuena mine, Zacatecas, Mexico. Six pure cultures were obtained using serial dilution and cross-streaking methods. Lithium tolerance was assessed through minimum inhibitory concentration (MIC) assays, revealing resistance levels between 5,000 and 20,000 ppm LiCl. Molecular characterization involved DNA extraction, amplification, purification, and restriction digestion with the HhaI enzyme, followed by sequencing. The isolates were identified as Stutzerimonas chloritidismutans, Microbacterium paraoxydans, Stenotrophomonas maltophilia, Bacillus cereus, and Bacillus ludwigii. Phylogenetic analysis was performed to resolve their evolutionary relationships. These findings highlight the untapped microbial diversity in lithium-rich mining residues and its promise for innovative applications in biohydrometallurgy.