Manganese sulfide formation via concomitant microbial manganese oxide and thiosulfate reduction
Manganese sulfide formation via concomitant microbial manganese oxide and thiosulfate reduction
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DOI：
10.1111/j.1462-2920.2011.02587.x
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发表时间：
2011-12-01
影响因子：
5.1
通讯作者：
Fredrickson, James K.
中科院分区：
文献类型：
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作者：
Lee, Ji-Hoon;Kennedy, David W.;Fredrickson, James K.
异化金属还原细菌圆锥希瓦氏菌MR-1在MnO(2)和硫代硫酸盐与H(2)氧化的同时还原过程中产生了γ-MnS纳米颗粒。为了研究微生物直接还原MnO(2)对MnS形成的影响，还使用了两株外膜c型细胞色素缺陷的MR-1突变体(Delta mtrC/Delta OMCA和Delta mtrC/Delta OMCA/Delta MtrF)，确定相对于硫代硫酸盐还原生成的生物硫化物，直接还原MnO(2)占主导地位。虽然培养基中排除了重碳酸盐，但菌株MR-1与乳酸盐作为电子供体孵育时，产生了MnCO(3)(菱锰矿)以及由显微X射线衍射(Micro-XRD)分析估计的几乎等量的MnS。结果表明，乳酸盐代谢释放的碳酸盐促进了MnCO(3)的生成，即使在富含硫化物和弱碱性的条件下，Mn(II)的矿物学也受到碳酸盐离子的强烈影响，有望有利于MnS的沉淀。结合显微X射线衍射仪、电子显微镜、能量色散X射线能谱和选区电子衍射分析确定的MnS的形成与平衡形态模型的预测是一致的。生物成因硫化锰可能是特定环境中锰生物地球化学循环中的锰汇，例如波罗的海内的深海缺氧海盆。
The dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1 produced gamma-MnS (rambergite) nanoparticles during the concurrent reduction of MnO(2) and thiosulfate coupled to H(2) oxidation. To investigate effect of direct microbial reduction of MnO(2) on MnS formation, two MR-1 mutants defective in outer membrane c-type cytochromes (Delta mtrC/Delta omcA and Delta mtrC/Delta omcA/Delta mtrF) were also used and it was determined that direct reduction of MnO(2) was dominant relative to chemical reduction by biogenic sulfide generated from thiosulfate reduction. Although bicarbonate was excluded from the medium, incubations of strain MR-1 with lactate as the electron donor produced MnCO(3) (rhodochrosite) as well as MnS in nearly equivalent amounts as estimated by micro X-ray diffraction (micro-XRD) analysis. It was concluded that carbonate released from lactate metabolism promoted MnCO(3) formation and that Mn(II) mineralogy was strongly affected by carbonate ions even in the presence of abundant sulfide and weakly alkaline conditions expected to favour the precipitation of MnS. Formation of MnS, as determined by a combination of micro-XRD, transmission electron microscopy, energy dispersive X-ray spectroscopy, and selected area electron diffraction analyses was consistent with equilibrium speciation modelling predictions. Biogenic manganese sulfide may be a manganese sink in the Mn biogeochemical cycle in select environments such as deep anoxic marine basins within the Baltic Sea.