Biogenic nanoscale vanadium magnetite is produced by converting V(V)-bearing ferrihydrites through reductive transformation using the metal-reducing bacterium Geobacter sulfurreducens. With increasing vanadium in the ferrihydrite, the amount of V-doped magnetite produced decreased due to V-toxicity which interrupted the reduction pathway ferrihydrite–magnetite, resulting in siderite or goethite formation. Fe L2,3 and V L2,3 X-ray absorption spectra and data from X-ray magnetic circular dichroism analysis revealed the magnetite to contain the V in the Fe(III) Oh site, predominately as V(III) but always with a component of V(VI), present a consistent V(IV)/V(III) ratio in the range 0.28 to 0.33. The bacteriogenic production of V-doped magnetite nanoparticles from V-doped ferrihydrite is confirmed and the work reveals that microbial reduction of contaminant V(V) to V(III)/V(IV) in the environment will occur below the Fe-redox boundary where it will be immobilised in biomagnetite nanoparticles.

生物纳米级钒磁铁矿是通过使用还原金属的细菌Geobacter sulfreducens通过还原转化将含V（V）的三水铁矿转化而成的。随着三水铁矿中钒的增加，由于V毒性而中断了三水铁矿-磁铁矿的还原途径，产生的V掺杂磁铁矿的数量减少，导致菱铁矿或针铁矿的形成。Fe L 2,3和V L 2,3的X射线吸收光谱和来自X射线磁性圆二色性分析的数据显示，磁铁矿在Fe（III）O h中包含V该位点主要为V（III），但始终带有V（VI）的一个组分，其V（IV）/ V（III）的比值始终在0.28至0.33的范围内。证实了由掺V的三水铁矿产生掺V的磁铁矿纳米颗粒的细菌生成作用，该工作表明，在Fe-氧化还原边界以下，环境中的微生物从污染物V（V）还原为V（III）/ V（IV）会发生。将其固定在生物磁铁矿纳米粒子中。