Microbial populations stimulated for hexavalent uranium reduction in uranium mine sediment
Microbial populations stimulated for hexavalent uranium reduction in uranium mine sediment
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DOI：
10.1128/aem.69.3.1337-1346.2003
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发表时间：
2003-03-01
影响因子：
4.4
通讯作者：
Banfield, JF
中科院分区：
文献类型：
--
作者：
Suzuki, Y;Kelly, SD;Banfield, JF
从一个非活性铀矿收集的铀污染沉积物和水厌氧培养与有机基质。受刺激的微生物种群在1个月内几乎完全从溶液中去除U。X射线吸收近边结构分析表明，U（VI）在孵育过程中被还原为U（IV）。透过透射电子显微镜、选区衍射图分析和能量色散X射线光谱分析的观察结果显示，两种不同类型的原核细胞只沉淀出一种U（IV）矿物晶质铀矿（UO 2）或同时沉淀出晶质铀矿和金属硫化物。与晶质铀矿和金属硫化物共生的原生细胞被推断为硫酸盐还原菌。16S核糖体DNA的系统发育分析显示，从原始和孵育的沉积物微生物种群的变化，从微需氧变形菌厌氧低G +C革兰氏阳性芽孢细菌的孵育。来自培养沉淀物的94个克隆中的42个与硫酸盐还原性Desulfiosporosinus spp.相关，23株与发酵型梭菌有关。结果表明，如果在铀矿池原位生物修复尝试，Desulfiosporosinus spp。将是U（VI）和硫酸盐还原的主要贡献者，梭菌属物种。U（VI）还原。
Uranium-contaminated sediment and water collected from an inactive uranium mine were incubated anaerobically with organic substrates. Stimulated microbial populations removed U almost entirely from solution within I month. X-ray absorption near-edge structure analysis showed that U(VI) was reduced to U(IV) during the incubation. Observations by transmission electron microscopy, selected area diffraction pattern analysis, and energy-dispersive X-ray spectroscopic analysis showed two distinct types of prokaryotic cells that precipitated only a U(IV) mineral uraninite (UO2) or both uraninite and metal sulfides. Prokaryotic cells associated with uraninite and metal sulfides were inferred to be sulfate-reducing bacteria. Phylogenetic analysis of 16S ribosomal DNA obtained from the original and incubated sediments revealed that microbial populations were changed from microaerophilic Proteobacteria to anaerobic low-G+C gram-positive sporeforming bacteria by the incubation. Forty-two out of 94 clones from the incubated sediment were related to sulfate-reducing Desulfiosporosinus spp., and 23 were related to fermentative Clostridium spp. The results suggest that, if in situ bioremediation were attempted in the uranium mine ponds, Desulfiosporosinus spp. would be a major contributor to U(VI) and sulfate reduction and Clostridium spp. to U(VI) reduction.