46-11 Microbiological Mining of Critical Minerals is Altered by Community Modifying Metal Enrichments

Session: Research to Accelerate Recovery of Critical Minerals from Primary and Secondary Resources

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Abstract:

The United States is emphasizing an era of domestic critical mineral and material (CMM) security through investigations into unconventional feedstocks. Abandoned coal mine drainage (AMD) in the Appalachian Basin has been identified as a potential source, with >2,000 µg/L total rare earth element (REE) content in AMD and >2,000 µg/g total REE existing in some remediated precipitants. Efficient and selective extraction from these complex precipitant matrices remain a challenge, and microbiological metal mining may provide a novel outlet for selective extraction using natural constituents of the AMD. Previous seasonal analysis of an AMD remediation system revealed strong correlations between REE and the common AMD elements: Al, Cu, and Zn. Preserved glycerol stocks of the microbial community from the most REE rich solids were enriched for tolerance to high levels of these metals. The resulting enrichment communities were evaluated for biological mining capacity through ICP-MS fluids analysis after being cultured with the sterilized REE rich feedstock they were originally derived from. Aluminum-tolerant biological mining cultures performed the best but initially demonstrated promiscuous solubilization of metals. By the final sampling date, these Al-tolerant biomining cultures demonstrated selective precipitation of aluminum while retaining REE in solution, which produced a cleaner, more industrially relevant REE feedstock. Biological mining culture communities, enriched communities, and original native communities were evaluated for microbial composition via 16S rRNA amplicon sequencing to identify microbial constituents contributing to reported results. These findings allow for more fine-tuned biological mining experiments in the development of CMM and REE extraction techniques.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-7014

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