In this research, we have demonstrated the ability of several yeast species to mediate U(VI) biomineralization through uranium phosphate biomineral formation when utilizing an organic source of phosphorus (glycerol 2-phosphate disodium salt hydrate (C3H7Na2O6P center dot xH(2)O (G2P)) or phytic acid sodium salt hydrate (C6H18O24P6 center dot xNa(+)center dot yH(2)O (PyA))) in the presence of soluble UO2(NO3)(2). The formation of meta-ankoleite (K-2(UO2)(2)(PO4)(2)center dot 6(H2O)), chernikovite ((H3O)(2)(UO2)(2)(PO4)(2)center dot 6(H2O)), bassetite (Fe++(UO2)(2)(PO4)(2)center dot 8(H2O)), and uramphite ((NH4)(UO2)(PO4)center dot 3(H2O)) on cell surfaces was confirmed by X-ray diffraction in yeasts grown in a defined liquid medium amended with uranium and an organic phosphorus source, as well as in yeasts pre-grown in organic phosphorus-containing media and then subsequently exposed to UO2(NO3)(2). The resulting minerals depended on the yeast species as well as physico-chemical conditions. The results obtained in this study demonstrate that phosphatase-mediated uranium biomineralization can occur in yeasts supplied with an organic phosphate substrate as sole source of phosphorus. Further understanding of yeast interactions with uranium may be relevant to development of potential treatment methods for uranium waste and utilization of organic phosphate sources and for prediction of microbial impacts on the fate of uranium in the environment.