Electrode hydrophilicity enhanced the rate of extracellular electron uptake in Desulfovibrio ferrophilus IS5
Electrode hydrophilicity enhanced the rate of extracellular electron uptake in Desulfovibrio ferrophilus IS5
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DOI：
10.1016/j.electacta.2022.140504
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发表时间：
2022-05-13
影响因子：
6.6
通讯作者：
Okamoto, Akihiro
中科院分区：
文献类型：
--
作者：
Deng, Xiao;Luo, Dan;Okamoto, Akihiro
硫酸盐还原菌胞外电子摄取（EEU）的测定对于理解厌氧铁腐蚀的机制至关重要。一些研究试图以嗜铁Desulfovibrio ferroophilus IS5为模型细菌来阐明EEU的机制。本研究考察了电极润湿性对EEU活性的影响以及IS5电池与电极界面上的电子传递机制。采用亲水性NH2-或sh -配体或疏水性CH3-配体对铟锡掺杂氧化物（ITO）电极的润湿性进行了修饰。随着电极亲水性的增加，与硫酸盐还原相结合的电流产生增加了多达9倍，并且与附着在电极上的细胞数量呈线性正相关。因此，is5介导的EEU很可能需要细胞直接附着在电极表面。差分脉冲伏安法表明，电极润湿性改变了IS5还原信号的峰电位和强度，这可能是由于IS5的外膜细胞色素（OMCs）与电极表面之间的直接相互作用。这些结果支持了IS5利用omc介导的直接EEU机制的假设，这对腐蚀和抗生物腐蚀材料的机制具有重要意义。
The determination of extracellular electron uptake (EEU) by sulfate-reducing bacteria is crucial for understanding the mechanism underlying anaerobic iron corrosion. Several studies have attempted to elucidate the mechanism underlying EEU using Desulfovibrio ferrophilus IS5 as the model bacterium. This study examined the impact of electrode wettability on EEU activity and the electron transfer mechanism at the interfaces between IS5 cells and electrodes. The wettability of indium-tin-doped oxide (ITO) electrodes was modified by dip-coating them with hydrophilic NH2- or SH-ligands or hydrophobic CH3- ligands. With increasing electrode hydrophilicity, current generation coupled with sulfate reduction increased by as much as nine-fold and displayed a positive linear correlation with the number of cells attached to the electrodes. Hence, IS5-mediated EEU most likely requires direct cell attachment to the electrode surfaces. Differential pulse voltammetry showed that electrode wettability altered the peak potential and intensity of the IS5 reductive signal possibly because of direct interactions between outer-membrane cytochromes (OMCs) in IS5 and the electrode surfaces. These results support the hypothesis that IS5 utilizes an OMC-mediated direct EEU mechanism, which has implications for the mechanism underlying corrosion and anti-biocorrosion material.