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Abstract Trace metals have been an important ingredient for life throughout Earth’s history. Here, we describe the genome-guided cultivation of a member of the elusive archaeal lineage Caldarchaeales (syn. Aigarchaeota ), Wolframiiraptor gerlachensis , and its growth dependence on tungsten. A metagenome-assembled genome (MAG) of W. gerlachensis encodes putative tungsten membrane transport systems, as well as pathways for anaerobic oxidation of sugars probably mediated by tungsten-dependent ferredoxin oxidoreductases that are expressed during growth. Catalyzed reporter deposition-fluorescence in-situ hybridization (CARD-FISH) and nanoscale secondary ion mass spectrometry (nanoSIMS) show that W. gerlachensis preferentially assimilates xylose. Phylogenetic analyses of 78 high-quality Wolframiiraptoraceae MAGs from terrestrial and marine hydrothermal systems suggest that tungsten-associated enzymes were present in the last common ancestor of extant Wolframiiraptoraceae . Our observations imply a crucial role for tungsten-dependent metabolism in the origin and evolution of this lineage, and hint at a relic metabolic dependence on this trace metal in early anaerobic thermophiles. 

Many natural water sources and industrial wastewaters contain low concentrations of metals and other contaminants. Therefore, an efficient and economical method for low-level contaminant removal and recovery is needed. The purpose of the research is to improve and modify a newly developed continuous flow ion exchange process for expansion to a variety of non-industrial applications, including removal of metal ions from the Upper Clark Fork River Watershed. The process involves a dual column reactor designed to capture metal ions using 90–105 μm spherical, functionalized silica gel coated magnetite particles, targeting copper ions with future expansion to additional metals, such as manganese and zinc. The optimization of nanoparticle synthesis and dispersion is ongoing with variables that include pH, metal ion concentration, nanoparticle concentration, and temperature. Additional focus involves maximizing contaminant capture, with current values of 0.19 mmol Cu/g Fe3O4 for magnetite and 0.25 mmol Cu/g Fe3O4 for silica-coated magnetite.