Abstract：
Microbial exudates including siderophore, which changes chemical species of actinides and lanthanides. We have investigated effects of desferrioxamine B (DFOB; one of the siderophores) and siderophore-like organic molecules (SLOM) on the adsorption of lanthanides by microbial cells, aluminium oxide (Al2O3), and manganese (Mn) oxides. When DFOB was present, the distribution coefficients of cerium (Ce) were measured to be lower than those of neighboring elements of lanthanum (La) and praseodymium (Pr) (Negative anomaly of Ce adsorption). Even though initial oxidation state of Ce in the solution was III, that was changed to IV after the addition of DFOB, indicating that Ce(III) was oxidized by forming complex with DFOB. When lanthanides were adsorbed by biogenic Mn(IV) oxides, negative anomaly of Ce adsorption was observed in the sorption in alkaline solution. Ce(III) was oxidized to forme the complexes of Ce(IV) with SLOM in the solution. These results show that siderophore possesses high performance of oxidation of Ce(III) to Ce(IV) during association, affectiong the adsorption behavior of Ce. After Fukushima accident, radioactive Cs accumulation by Eleutherococcus sciadophylloides (Koshiabura) caused by the dissolution of Fe from soil around the roots, that was dominated by siderophore releasing microorganisms (SB). These SBs may enhance dissolution of iron (Fe) and uranium (U) phases in the nuclear fuel debris formed in the nuclear reactors in Fukushima Daiichi nuclear power plant. Thus, in the interaction between microorganisms and radionuclides, SLOMs discharged by microorganisms are deeply involved in the chemical state change of radionuclides.
摘要：
微生物分泌物，包括铁载体，这改变了act系元素和镧系元素的化学物种。我们已经研究了去铁胺B（DFOB;铁载体之一）和铁载体样有机分子（SLOM）对微生物细胞吸附镧系元素的影响，氧化铝(Al2O3),和锰(Mn)氧化物。当DFOB出现时，测得铈（Ce）的分布系数低于邻近元素镧（La）和镨（Pr）的分布系数（Ce吸附的负异常）。即使溶液中Ce的初始氧化态为III，在添加DFOB后更改为IV，表明Ce(III)通过与DFOB形成络合物而被氧化。当镧系元素被生物Mn(IV)氧化物吸附时，在碱性溶液中的吸附中观察到Ce吸附的负异常。将Ce（III）氧化以在溶液中形成Ce（IV）与SLOM的配合物。这些结果表明，铁载体在缔合过程中具有Ce（III）氧化为Ce（IV）的高性能，研究了Ce的吸附行为。在福岛事故之后,由于根部周围土壤中的Fe溶解而引起的接连木雪莲球菌（Koshiabura）的放射性Cs积累，以释放铁载体的微生物（SB）为主。这些SB可以增强福岛第一核电站核反应堆中形成的核燃料碎片中的铁（Fe）和铀（U）相的溶解。因此，在微生物和放射性核素之间的相互作用中，微生物释放的SLOM与放射性核素的化学状态变化密切相关。
