Extracellular electron transfer via microbial nanowires
Extracellular electron transfer via microbial nanowires
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DOI：
10.1038/nature03661
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发表时间：
2005-06-23
期刊：
影响因子：
64.8
通讯作者：
Lovley, DR
中科院分区：
文献类型：
--
作者：
Reguera, G;McCarthy, KD;Lovley, DR
能够将电子转移到细胞外电子受体的微生物，如Fe（III）氧化物，在土壤和沉积物中的有机物降解和养分循环中是重要的（1,2）。先前对电子转移到Fe（III）的研究主要集中在外膜c型细胞色素的作用上（1,3）。然而，一些Fe（III）还原剂缺乏c-细胞色素(4)。地杆菌是许多环境中主要的铁（III）还原剂(1)，必须直接接触铁（III）氧化物来还原它们(5)，并产生单侧毛(6)，这是根据毛在其他生物中的作用（7,8）提出的（1,2），以帮助与铁（III）氧化物建立接触。在这里，我们报道了硫还原地杆菌的一个缺菌突变体不能还原铁（III）氧化物，但可以附着在它们上面。导电探针原子力显微镜显示毛毛具有高导电性。这些结果表明G.硫还原菌的菌毛可能作为生物纳米线，将电子从细胞表面转移到Fe（III）氧化物表面。通过毛的电子转移表明了其他独特的细胞表面和细胞间相互作用的可能性，以及新型导电材料的生物工程。
Microbes that can transfer electrons to extracellular electron acceptors, such as Fe(III) oxides, are important in organic matter degradation and nutrient cycling in soils and sediments(1,2). Previous investigations on electron transfer to Fe(III) have focused on the role of outer-membrane c-type cytochromes(1,3). However, some Fe(III) reducers lack c-cytochromes(4). Geobacter species, which are the predominant Fe(III) reducers in many environments(1), must directly contact Fe(III) oxides to reduce them(5), and produce monolateral pili(6) that were proposed(1,2), on the basis of the role of pili in other organisms(7,8), to aid in establishing contact with the Fe(III) oxides. Here we report that a pilus-deficient mutant of Geobacter sulfurreducens could not reduce Fe(III) oxides but could attach to them. Conducting-probe atomic force microscopy revealed that the pili were highly conductive. These results indicate that the pili of G. sulfurreducens might serve as biological nanowires, transferring electrons from the cell surface to the surface of Fe(III) oxides. Electron transfer through pili indicates possibilities for other unique cell-surface and cell-cell interactions, and for bioengineering of novel conductive materials.