Reduction of Soluble Iron and Reductive Dissolution of Ferric Iron-Containing Minerals by Moderately Thermophilic Iron-Oxidizing Bacteria
Reduction of Soluble Iron and Reductive Dissolution of Ferric Iron-Containing Minerals by Moderately Thermophilic Iron-Oxidizing Bacteria
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DOI：
10.1128/aem.64.6.2181-2186.1998
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发表时间：
1998-06
影响因子：
4.4
通讯作者：
T. Bridge;D. B. Johnson
中科院分区：
文献类型：
--
作者：
T. Bridge;D. B. Johnson
摘要五种中度嗜热的铁氧化细菌，包括三种分类的代表菌株（氧化热硫硫杆菌，嗜酸乳杆菌，氧化亚铁酸微菌），被证明是能够还原三价铁亚铁，当他们在氧气限制条件下生长。铁还原是最容易观察到的菌株生长时，作为混合营养或异养与甘油作为电子供体;此外，一些菌株能够耦合连四硫酸盐的氧化还原三价铁。在需氧条件下培养的未摇动烧瓶中，在分批培养生长期间观察到铁在亚铁态和三价铁态之间的循环，尽管铁的氧化还原模式在不同种类的铁氧化中度嗜热菌和单一种类的菌株中不同（S.嗜酸乳杆菌）。所有这三种细菌都能在厌氧条件下生长，三价铁作为唯一的电子受体;当分离株在无氧条件下生长时，生长产量与三价铁的量减少相关。一株中度嗜热菌（鉴定为S.嗜酸乳杆菌）在以甘油作为碳源和能源的限制通气条件下生长时，能够引起三种含三价铁矿物（氢氧化铁、黄钾铁矾和针铁矿）的还原溶解。适度嗜热铁氧化剂还原铁在环境和应用背景下的意义进行了讨论。
ABSTRACT Five moderately thermophilic iron-oxidizing bacteria, including representative strains of the three classified species (Sulfobacillus thermosulfidooxidans, Sulfobacillus acidophilus, and Acidimicrobium ferrooxidans), were shown to be capable of reducing ferric iron to ferrous iron when they were grown under oxygen limitation conditions. Iron reduction was most readily observed when the isolates were grown as mixotrophs or heterotrophs with glycerol as an electron donor; in addition, some strains were able to couple the oxidation of tetrathionate to the reduction of ferric iron. Cycling of iron between the ferrous and ferric states was observed during batch culture growth in unshaken flasks incubated under aerobic conditions, although the patterns of oxidoreduction of iron varied in different species of iron-oxidizing moderate thermophiles and in strains of a single species (S. acidophilus). All three bacterial species were able to grow anaerobically with ferric iron as a sole electron acceptor; the growth yields correlated with the amount of ferric iron reduced when the isolates were grown in the absence of oxygen. One of the moderate thermophiles (identified as a strain of S. acidophilus) was able to bring about the reductive dissolution of three ferric iron-containing minerals (ferric hydroxide, jarosite, and goethite) when it was grown under restricted aeration conditions with glycerol as a carbon and energy source. The significance of iron reduction by moderately thermophilic iron oxidizers in both environmental and applied contexts is discussed.