We are aware of only two prior efforts at directed evolution of inorganic oxidoreductases: In one instance, a chromate reductase was evolved using a 96-well plate NAD(P)H assay to increase reduction kinetics for Cr(IV) and U(VI) . In a second example, ferritin was evolved to exhibit improved physical attraction to magnets through altered biomineralization of iron . Notably, these examples did not change substrate selectivity. Rather these studies altered enzyme kinetics toward existing substrates or altered the physicochemical nature of the product. Therefore, to the extent of our knowledge, there are no known examples where metal(loid) reductase substrate specificities are altered through laboratory directed evolution.