Effect of Fe(II) and Fe(III) Transformation Kinetics on Iron Acquisition by a Toxic Strain of Microcystis aeruginosa
Effect of Fe(II) and Fe(III) Transformation Kinetics on Iron Acquisition by a Toxic Strain of Microcystis aeruginosa
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DOI：
10.1021/es901315a
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发表时间：
2010-03-15
影响因子：
11.4
通讯作者：
Waite, T. David
中科院分区：
文献类型：
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作者：
Fujii, Manabu;Rose, Andrew L.;Waite, T. David
我们研究了一种有毒的淡水蓝藻绿微囊藻（PCC7806）对铁的吸收机制，特别关注了铁（II）和铁（III）转化动力学对铁吸收的影响。化学发光分析显示，M. aeruginosa产生细胞外超氧化物（一种中等铁还原剂）的速率为0.4-1.2 amol cell(-1) h(-1)，取决于培养基中初始铁浓度。使用Fe-55进行的短期同化试验表明，当铁的有效性由于使用强铁螯合剂乙二胺四乙酸酯（EDTA）作为配体而降低时，细胞产生的超氧化物或抗坏血酸盐通过形成未螯合的铁（II）来还原有机和无机形式的铁（III），从而促进了铁的吸收。相比之下，在低浓度的情况下，铁的还原对铁的吸收不重要(
We have investigated the mechanism of Fe uptake by a toxic strain of the freshwater cyanobacterium Microcystis aeruginosa (PCC7806) with particular attention given to the effect of Fe(II) and Fe(III) transformation kinetics on Fe uptake. Chemiluminescence analysis revealed that M. aeruginosa produces extracellular superoxide (a moderate Fe reducing agent) at rates of 0.4-1.2 amol cell(-1) h(-1) depending on initial Fe concentration in the culture medium. Short-term assimilation assays using Fe-55 showed that reduction of Fe(III) in both organic and inorganic forms by cell-generated superoxide or ascorbate facilitated Fe uptake via formation of unchelated Fe(II), when Fe availability was low because of the use of the strong Fe chelator ethylenediaminetetra acetate (EDTA) as a ligand. In contrast, Fe reduction was unimportant for Fe uptake in the presence of low concentrations (