Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Sigwartstrasse 10, D-72076 Tübingen, Germany.
Environ Sci Technol. 2012 Jun 19;46(12):6556-65. doi: 10.1021/es2046266. Epub 2012 Jun 1.
The mobility of toxic metals and the transformation of organic pollutants in the environment are influenced and in many cases even controlled by iron minerals. Therefore knowing the factors influencing iron mineral formation and transformation by Fe(II)-oxidizing and Fe(III)-reducing bacteria is crucial for understanding the fate of contaminants and for the development of remediation technologies. In this study we followed mineral formation by the nitrate-reducing Fe(II)-oxidizing strain Acidovorax sp. BoFeN1 in the presence of the crystalline Fe(III) (oxyhydr)oxides goethite, magnetite and hematite added as potential nucleation sites. Mössbauer spectroscopy analysis of minerals precipitated by BoFeN1 in (57)Fe(II)-spiked microbial growth medium showed that goethite was formed in the absence of mineral additions as well as in the presence of goethite or hematite. The presence of magnetite minerals during Fe(II) oxidation induced the formation of magnetite in addition to goethite, while the addition of humic substances along with magnetite also led to goethite but no magnetite. This study showed that mineral formation not only depends on the aqueous geochemical conditions but can also be affected by the presence of mineral nucleation sites that initiate precipitation of the same underlying mineral phases.
环境中有毒金属的迁移和有机污染物的转化受到铁矿物的影响，在许多情况下甚至受到铁矿物的控制。因此，了解影响 Fe(II)-氧化和 Fe(III)-还原细菌中铁矿物形成和转化的因素，对于了解污染物的归宿和开发修复技术至关重要。在这项研究中，我们在添加了可能的成核位点（结晶态）Fe(III)（氧氢）氧化物针铁矿、磁铁矿和赤铁矿的情况下，跟踪了硝酸盐还原的 Fe(II)氧化菌 Acidovorax sp. BoFeN1 形成的矿物。BoFeN1 在（57）Fe(II)-加标微生物生长培养基中沉淀的矿物的穆斯堡尔光谱分析表明，在没有矿物添加的情况下以及在存在针铁矿或赤铁矿的情况下都形成了针铁矿。在 Fe(II)氧化过程中存在磁铁矿矿物时，除了针铁矿之外还诱导了磁铁矿的形成，而在添加腐殖质的同时也导致了针铁矿的形成但没有磁铁矿。本研究表明，矿物的形成不仅取决于水地球化学条件，还可能受到矿物成核位点的存在的影响，这些成核位点会引发相同潜在矿物相的沉淀。
