The environmental impact of uranium released during nuclear power production and related mining activity is an issue of great concern. Innovative environmental-friendly water remediation strategies, like those based on U biomineralization through phosphatase activity, are desirable. Here, we report the great U biomineralization potential of Stenotrophomonas sp. Br8 CECT 9810 over a wide range of physicochemical and biological conditions. Br8 cells exhibited high phosphatase activity which mediated the release of orthophosphate in the presence of glycerol-2-phosphate around pH 6.3. Mobile uranyl ions were bioprecipitated as needle-like fibrils at the cell surface and in the extracellular space, as observed by Scanning Transmission Electron Microscopy (STEM). Extended X-Ray Absorption Fine Structure (EXAFS) and X-Ray Diffraction (XRD) analyses showed the local structure of biogenic U precipitates to be similar to that of meta-autunite. In addition to the active U phosphate biomineralization process, the cells interact with this radionuclide through passive biosorption, removing up to 373 mg of U per g of bacterial dry biomass. The high U biomineralization capacity of the studied strain was also observed under different conditions of pH, temperature, etc. Results presented in this work will help to design efficient U bioremediation strategies for real polluted waters.

核电生产和相关采矿活动中释放的铀对环境的影响是一个令人高度关注的问题。人们希望有一种创新的环保水修复策略，例如那些基于磷酸酶活性的U生物矿化的水修复策略。在这里，我们报道了嗜麦芽单胞菌的巨大U生物矿化潜力sp。Br8 CECT 9810具有广泛的物理化学和生物学条件。Br8细胞表现出高磷酸酶活性，在pH 6.3左右的甘油2-磷酸存在下，介导正磷酸盐的释放。如通过扫描透射电子显微镜（STEM）所观察到的，移动的铀酰离子在细胞表面和细胞外空间中以针状原纤维形式生物沉淀。扩展的X射线吸收精细结构（EXAFS）和X射线衍射（XRD）分析表明，生物U沉淀的局部结构与准金铁矿相似。除了活性的U磷酸盐生物矿化过程外，细胞还通过被动生物吸附作用与放射性核素相互作用，每克细菌干生物量最多去除373 mgU。