Bioaccumulation of U(VI) by Sulfolobus acidocaldarius under moderate acidic conditions
Bioaccumulation of U(VI) by Sulfolobus acidocaldarius under moderate acidic conditions
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DOI：
10.1524/ract.2011.1848
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发表时间：
2011-01-01
影响因子：
1.8
通讯作者：
Selenska-Pobell, S.
中科院分区：
文献类型：
--
作者：
Reitz, T.;Merroun, M. L.;Selenska-Pobell, S.
研究了酸性嗜热古菌嗜酸热硫化叶菌（Sulfolobus acidocaldarius）在pH为4.5的中等酸性条件下对铀（VI）的富集作用。该pH值与某些重金属和铀污染环境有关，其中S.发现酸热症持续存在。我们证明，U（VI）是迅速复杂的古细菌细胞。X-射线吸收光谱和时间分辨激光诱导荧光光谱的组合显示，在pH 4.5的有机磷酸盐和羧基参与U（VI）络合。这些结果是在相反的大多数细菌，在此pH值沉淀U（VI）主要是在无机磷酸铀酰相出版。正如TEM所证明的那样，在所研究的古细菌中，只有有限部分添加的U（VI）在细胞外发生生物矿化。大部分U（VI）的积累是以细胞内沉积物的形式存在于细胞质膜的内侧。观察到的差异U（VI）的生物积累之间的研究古菌和细菌可以解释的显着差异，在他们的细胞壁结构，以及他们不同的生理特性。
U(VI) accumulation by the acidothermophilic archaeon Sulfolobus acidocaldarius at a moderate acidic pH of 4.5 was investigated. This pH value is relevant for some heavy metal and uranium polluted environments where populations of S. acidocaldarius were found to persist. We demonstrate that U(VI) is rapidly complexed by the archaeal cells. A combination of X-ray absorption spectroscopy and time-resolved laser-induced fluorescence spectroscopy revealed that at pH 4.5 organic phosphate and carboxylic groups are involved in the U(VI) complexation. These results are in contrast to those published for most bacteria which at this pH precipitate U(VI) mainly in inorganic uranyl phosphate phases. As demonstrated by TEM only a limited part of the added U(VI) was biomineralized extracellularly in the case of the studied archaeon. Most of the U(VI) accumulates were localized in a form of intracellular deposits which were associated with the inner side of the cytoplasma membrane. Observed differences in U(VI) bioaccumulation between the studied archaeon and bacteria can be explained by the significant differences in their cell wall structures as well as by their different physiological characteristics.