Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany.
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany.
J Hazard Mater. 2022 Oct 5;439:129520. doi: 10.1016/j.jhazmat.2022.129520. Epub 2022 Jul 5.
Daucus carota suspension cells showed a high affinity towards Eu(III) and U(VI) based on a single-step bioassociation process with an equilibrium after 48-72 h. Cells responded with an increased metabolic activity towards heavy metal stress. Luminescence spectroscopy pointed to multiple species for both f-block elements in the culture media, providing initial hints of their interaction with cells and released metabolites. Using nuclear magnetic resonance spectroscopy, we could prove that malate, as an released metabolite in the culture medium, was found to complex with U. Luminescence spectroscopy also showed that Eu(III)-EDTA species are interacting with the cells. Furthermore, Eu(III) and U(VI) coordination is dominated by phosphate groups provided by the cells. We found that Ca ion channels of D. carota cells were involved in the uptake of U(VI), which led to a bioprecipitation of U(VI) in the vacuole of the cells, most probably as uranyl(VI) phosphates along with an intracellular sorption of U(VI) on biomembranes by lipid structures. Eu(III) could be found locally concentrated in the cell wall and in the cytoplasm with a co-localization with phosphorous and oxygen.
胡萝卜悬浮细胞表现出对 Eu(III)和 U(VI)的高亲和力，这是基于单一的生物结合过程，在 48-72 小时后达到平衡。细胞对重金属胁迫表现出更高的代谢活性。荧光光谱表明，在培养介质中，两种 f 区元素都存在多种物种，这为它们与细胞和释放的代谢物的相互作用提供了初步线索。通过核磁共振波谱，我们可以证明，在培养基中作为释放代谢物的苹果酸与 U 形成配合物。荧光光谱还表明，Eu(III)-EDTA 物种与细胞相互作用。此外，Eu(III)和 U(VI)的配位主要由细胞提供的磷酸盐基团控制。我们发现，胡萝卜细胞的 Ca 离子通道参与了 U(VI)的摄取，这导致 U(VI)在细胞液泡中生物沉淀，很可能是作为铀酰(VI)磷酸盐，同时在生物膜上通过脂质结构对 U(VI)进行内吸。Eu(III)可以在细胞壁和细胞质中局部集中，与磷和氧共定位。
