Bioreduction of biotite and chlorite by a Shewanella species
Bioreduction of biotite and chlorite by a Shewanella species
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DOI：
10.2138/am.2014.4774ccby
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发表时间：
2014-08
影响因子：
3.1
通讯作者：
D. Brookshaw;J. Lloyd;D. Vaughan;R. Pattrick
中科院分区：
文献类型：
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作者：
D. Brookshaw;J. Lloyd;D. Vaughan;R. Pattrick
摘要研究了铁（III）还原菌希瓦氏菌MR-1与层状硅酸盐矿物黑云母和绿泥石的相互作用。在洗涤、不生长的细胞悬浮液中，无论是否存在人工电子穿梭，S. oneidensis MR-1都能介导黑云母和绿泥石中铁（III）的还原，并能减少黑云母中36%的初始铁（III），减少绿泥石中21%的初始铁（III）。这主要是一个固态反应，因为在微生物还原后没有观察到明显的溶解或形态变化。在生长细胞实验中，以铁（III）作为唯一的电子受体，细菌生物量在8周的培养中增加。结合（弱酸可萃取）铁的铁锌测定结果和固体铁矿物的Mössbauer光谱表征结果，研究了固体铁矿物中铁（III）还原的可能机制。沿着八面体层M2位点之间的远距离电子转移可能有利于块状矿物的还原。据我们所知，这是第一个证明微生物介导的黑云母体内铁（III）还原的研究，并显示了S. oneidensis MR-1从这种还原中为生长保存能量的能力。
Abstract The interactions between the Fe(III)-reducing bacterium Shewanella oneidensis MR-1 and the phyllosilicate minerals biotite and chlorite have been studied. In washed, non-growing cell suspensions, S. oneidensis MR-1 was able to mediate the reduction of Fe(III) in biotite and chlorite in the presence and absence of an artificial electron shuttle, and to reduce as much as 36% of the starting Fe(III) in biotite, and 21% in chlorite. This is predominantly a solid-state reaction, as no significant dissolution or change in morphology was observed after microbial reduction. In growing-cell experiments, with Fe(III) as the only electron acceptor, bacterial biomass increased over eight weeks of incubation. Combining the results of (weak acid-extractable) iron characterization by ferrozine assay and bulk solid iron mineral characterization using Mössbauer spectroscopy, has led to the development of a possible mechanism of reduction of Fe(III) in the bulk of the mineral. Long-distance electron transfer between M2 sites along octahedral layers may facilitate the reduction of the bulk mineral. To our knowledge, this is the first study to demonstrate microbially mediated reduction of Fe(III) within biotite, and show the ability of S. oneidensis MR-1 to conserve energy for growth from this reduction.