Sharp Jonathan O, Schofield Eleanor J, Veeramani Harish, Suvorova Elena I, Kennedy David W, Marshall Matthew J, Mehta Apurva, Bargar John R, Bernier-Latmani Rizlan
Ecole Polytechnique Federale de Lausanne (EPFL), Switzerland.
Environ Sci Technol. 2009 Nov 1;43(21):8295-301. doi: 10.1021/es901281e.
While the product of microbial uranium reduction is often reported to be "UO(2)", a comprehensive characterization including stoichiometry and unit cell determination is available for only one Shewanella species. Here, we compare the products of batch uranyl reduction by a collection of dissimilatory metal- and sulfate-reducing bacteria of the genera Shewanella, Geobacter, Anaeromyxobacter, and Desulfovibrio under similar laboratory conditions. Our results demonstrate that U(VI) bioreduction by this assortment of commonly studied, environmentally relevant bacteria leads to the precipitation of uraninite with an approximate composition of UO(2.0), regardless of phylogenetic or metabolic diversity. Coupled analyses, including electron microscopy, X-ray absorption spectroscopy, and powder diffraction, confirm that structurally and chemically analogous uraninite solids are produced. These biogenic uraninites have particle diameters of about 2-3 nm and lattice constants consistent with UO(2.0) and exhibit a high degree of intermediate-range order. Results indicate that phylogenetic and metabolic variability within delta- and gamma-proteobacteria has little effect on biouraninite structure or crystal size under the investigated conditions.
虽然微生物还原铀的产物通常被报道为“UO₂”，但只有一种希瓦氏菌属的物种有包括化学计量和晶胞测定在内的全面表征。在这里，我们比较了在相似实验室条件下，希瓦氏菌属、地杆菌属、厌氧粘细菌属和脱硫弧菌属等异化金属还原菌和硫酸盐还原菌对铀酰进行批量还原的产物。我们的结果表明，这种经过广泛研究的、与环境相关的细菌对U(VI)进行生物还原会导致晶质铀矿沉淀，其近似组成为UO₂.₀，无论其系统发育或代谢多样性如何。包括电子显微镜、X射线吸收光谱和粉末衍射在内的联合分析证实，生成了结构和化学性质类似的晶质铀矿固体。这些生物成因的晶质铀矿颗粒直径约为2 - 3纳米，晶格常数与UO₂.₀一致，并表现出高度的中程有序性。结果表明，在所研究的条件下，δ-和γ-变形菌纲内的系统发育和代谢变异性对生物成因晶质铀矿的结构或晶体大小影响很小。
