It is expected that modification of metal(loid) reductase enzyme substrate specificities will benefit several academic and industrial applications. Biomining and bioremediation of metals are nascent fields which currently rely on intact microbes to extract metals from heterogeneous mixtures . Molecular mechanisms underlying the microbial extractions are scarcely characterized . Identification, improvement, or alteration of enzymatic processes underlying biomining may facilitate use of 'greener' approaches to metal(loid) mining.