In this paper, we used spectroscopic and microscopic techniques to investigate the interaction mechanism between uranium and Bacillus mucilaginosus. According to scanning electron microscope couple with energy dispersive X-ray detector analysis, the lamellar uranium phosphate precipitation was only observed on the living B. mucilaginosus and the resting B. mucilaginosus. The Fourier transform infrared spectroscopy spectrum also indicated the important role of phosphate groups in forming U(VI)-phosphates precipitation. The X-ray diffraction analysis identified the phase of U(VI)-phosphate precipitation as H₃OUO₂PO₄·3H₂O. Batch experiment showed that biominerilization amount could be up to 195.84 mg/g when exposing living B. mucilaginosus to U(VI) aqueous solution at pH 5.0 for 1 h. The precipitate was further evidenced by extended X-ray absorption fine structure spectra based on the presence of U–P shell, which demonstrated that hydrogen uranyl phosphate became the main products on the living B. mucilaginosus with prolonged reacting time. After ashing and hydrothermal process, the precipitated U(VI) on B. mucilaginosus could be converted into UO₂ and K(UO₂)(PO₄)·3H₂O. Our findings have significant implications in elucidating the potential role of bacteria in the migration of uranium in geological environment.

中文翻译：

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黏杆菌芽孢杆菌沉淀的铀磷酸盐矿物的显微和光谱学洞察

在本文中，我们使用光谱学和显微技术研究了铀与粘液芽孢杆菌之间的相互作用机理。根据扫描电子显微镜结合能量色散X射线检测器分析，仅在活的粘液芽孢杆菌和静止的粘液芽孢杆菌中观察到层状磷酸铀沉淀。傅里叶变换红外光谱也表明了磷酸基团在形成U（VI）-磷酸盐沉淀中的重要作用。X射线衍射分析确定了U（VI）-磷酸盐沉淀的相为H ₃ OUO ₂ PO ₄ ·3H ₂O.批处理实验表明，当将活的粘枝芽孢杆菌暴露于pH 5.0的U（VI）水溶液中1 h时，生物矿化量可高达195.84 mg / g 。基于U–P壳的存在，通过扩展的X射线吸收精细结构光谱进一步证实了该沉淀物，这表明磷酸铀氧磷酸酯成为活的粘液芽胞杆菌的主要产物，反应时间延长。经过灰化和水热处理后，粘液芽孢杆菌上沉淀的U（VI）可以转化为UO ₂和K（UO ₂）（PO ₄）·3H _2。O.我们的发现对阐明细菌在地质环境中铀迁移中的潜在作用具有重要意义。