Maghemite (γ-Fe2O3) nanoparticles enhance dissimilatory ferrihydrite reduction by Geobacter sulfurreducens: Impacts on iron mineralogical change and bacterial interactions
Maghemite (γ-Fe2O3) nanoparticles enhance dissimilatory ferrihydrite reduction by Geobacter sulfurreducens: Impacts on iron mineralogical change and bacterial interactions
复制标题
磁赤铁矿（γ-Fe2O3）纳米颗粒增强硫还原地杆菌对水铁矿的异化还原：对铁矿物学变化和细菌相互作用的影响
DOI：
10.1016/j.jes.2018.09.021
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发表时间：
2019-04-01
影响因子：
6.9
通讯作者：
Wang, Yuanpeng
中科院分区：
文献类型：
--
作者：
Chen, Zheng;Zhang, Yaxian;Wang, Yuanpeng
微生物介导的羟基氧化铁生物还原在铁的生物地球化学循环中起着重要作用。硫还原地杆菌是一种代表性的异化铁还原细菌，可组装导电菌毛和细胞色素。研究了补充 γ-Fe2O3 纳米颗粒 (NP)（0.2 和 0.6 g）对硫还原杆菌介导的水铁矿还原的影响。在γ-Fe2O3 NPs介导的微生物水铁矿还原的总体性能中，在与γ-Fe2O3 NPs直接接触的情况下观察到比间接接触更强的还原作用。与仅使用水铁矿的生物修饰产生的 Fe(II) 产量相比，在与 0.2 g 和 0.6 g γ-Fe2O3 NP 直接接触的生物修饰中检测到 Fe(II) 产量分别增加了 1.6 倍和 1.4 倍。 X射线衍射分析表明，当活性G.sulfurreducens细胞与γ-Fe2O3NPs直接接触时，磁铁矿是水铁矿中独特的代表性铁矿物。由于生物 Fe(II) 吸附在 γ-Fe2O3 纳米颗粒上而不是水铁矿上，因此添加 γ-Fe2O3 纳米颗粒还可以通过防止水铁矿表面钝化来有助于增加水铁矿还原的持续时间。此外，电子显微镜分析证实，直接添加 γ-Fe2O3 纳米颗粒会刺激导电菌毛和细胞色素拉伸，促进细胞和水铁矿之间的长程电子转移。所获得的发现为氧化铁纳米颗粒对土壤生物地球化学的影响提供了更全面的了解。 (c) 2018 中国科学院生态环境研究中心。由 Elsevier B.V. 出版
Microbially mediated bioreduction of iron oxyhydroxide plays an important role in the biogeochemical cycle of iron. Geobacter sulfurreducens is a representative dissimilatory iron-reducing bacterium that assembles electrically conductive pili and cytochromes. The impact of supplementation with gamma-Fe2O3 nanoparticles (NPs) (0.2 and 0.6 g) on the G. sulfurreducens-mediated reduction of ferrihydrite was investigated. In the overall performance of microbial ferrihydrite reduction mediated by gamma-Fe2O3 NPs, stronger reduction was observed in the presence of direct contact with gamma-Fe2O3 NPs than with indirect contact. Compared to the production of Fe(II) derived from biotic modification with ferrihydrite alone, increases greater than 1.6-and 1.4-fold in the production of Fe(II) were detected in the biotic modifications in which direct contact with 0.2 g and 0.6 g gamma-Fe2O3 NPs, respectively, occurred. X-ray diffraction analysis indicated that magnetite was a unique representative iron mineral in ferrihydrite when active G. sulfurreducens cells were in direct contact with gamma-Fe2O3 NPs. Because of the sorption of biogenic Fe(II) onto gamma-Fe2O3 NPs instead of ferrihydrite, the addition of gamma-Fe2O3 NPs could also contribute to increased duration of ferrihydrite reduction by preventing ferrihydrite surface passivation. Additionally, electron microscopy analysis confirmed that the direct addition of gamma-Fe2O3 NPs stimulated the electrically conductive pili and cytochromes to stretch, facilitating long-range electron transfer between the cells and ferrihydrite. The obtained findings provide a more comprehensive understanding of the effects of iron oxide NPs on soil biogeochemistry. (c) 2018 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.