Lin Bin, Hyacinthe Christelle, Bonneville Steeve, Braster Martin, Van Cappellen Philippe, Röling Wilfred F M
Department of Molecular Cell Physiology, Faculty of Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
Environ Microbiol. 2007 Aug;9(8):1956-68. doi: 10.1111/j.1462-2920.2007.01312.x.
The potential for dissimilatory ferric iron [Fe(III)] reduction in intertidal sediments of the polluted Scheldt estuary, Northwest Europe, was assessed by combining field-based geochemical measurements with laboratory experiments on the associated microbiology. Microbial communities at a freshwater and brackish location were characterized by culture-independent 16S rRNA gene analysis, as well as enrichments, strain isolation and physiological screening. Dilution-to-extinction batch enrichments using a variety of Fe(III) sources were performed. The dilution factor of the inoculum in the enrichments had a more determining effect on the Fe(III)-reducing microbial community structure than the Fe(III) source. Well-known Fe(III) reducers, including members of the family Geobacteraceae and the genus Shewanella, constituted only a small fraction (< or = 1%) of the in situ microbial community. Instead, facultative anaerobic Ralstonia and strictly anaerobic, spore-forming Clostridium species dominated Fe(III) reduction. These species were able to utilize a variety of electron acceptors. This flexibility may help the organisms to survive in the dynamic estuarine environment. The high diversity and abundance of culturable Fe(III) reducers (4.6 x 10(5) and 2.4 x 10(4) cells g(-1) sediment at the freshwater and brackish site respectively), plus the high concentrations of chemically reducible solid-phase Fe(III) at the sites, implied a high potential for dissimilatory Fe(III) reduction in the estuarine sediments. Pore water chemical data further supported in situ dissimilatory Fe(III) reduction.
通过将基于现场的地球化学测量与相关微生物学的实验室实验相结合，评估了欧洲西北部受污染的斯海尔德河口潮间带沉积物中异化铁[Fe(III)]还原的潜力。通过非培养的16S rRNA基因分析以及富集、菌株分离和生理筛选，对淡水和微咸水区域的微生物群落进行了表征。使用多种Fe(III)源进行了稀释至灭绝的批次富集实验。富集物中接种物的稀释因子对Fe(III)还原微生物群落结构的影响比Fe(III)源更大。包括地杆菌科成员和希瓦氏菌属在内的著名Fe(III)还原菌仅占原位微生物群落的一小部分（≤1%）。相反，兼性厌氧的罗尔斯通氏菌属和严格厌氧的产芽孢梭菌属主导了Fe(III)的还原。这些物种能够利用多种电子受体。这种灵活性可能有助于这些生物在动态的河口环境中生存。可培养的Fe(III)还原菌具有很高的多样性和丰度（淡水和微咸水区域的沉积物中分别为4.6×10⁵和2.4×10⁴个细胞g⁻¹），加上这些地点化学可还原固相Fe(III)的高浓度，这意味着河口沉积物中异化Fe(III)还原具有很高的潜力。孔隙水化学数据进一步支持了原位异化Fe(III)还原。
