有“生命”的电线:浅析微生物纳米导线电子传递机制及其应用

微生物纳米导线是指在缺少可溶性电子受体的条件下由微生物形成类似菌毛的导电附属物,通过它传递电子是微生物为提高胞外电子传递效率而进化形成的一种有效的电子传递方式。微生物可利用具有高效导电特性的纳米导线将电子传递到远离细胞表面的地方,从而使微生物摆脱了需要直接接触胞外电子受体(Fe(Ⅲ)氧化物或电极)才能传递电子的限制。微生物纳米导线的发现丰富了人们对胞外呼吸多样性的认识,同时其在提高微生物燃料电池产电效率、促进环境中有机污染物的快速降解和生物能源等方面具有重要的应用前景,成为了当前研究的前沿和热点。本文简单介绍了微生物纳米导线的基本特性和产生纳米导线的微生物种类,重点阐述了由Geobacter和Shewanella微生物生成的纳米导线电子传递机制以及其在生物能源和生物修复等方面的应用,并展望了今后的研究重点。

Live Wire: A Review on Electron Transfer Mechanism and Applications of Microbial Nanowires

Microbial nanowires are electrically conductive pilus-like appendages,which are produced under soluble electron acceptor-limiting conditions.The findings of microbial nanowires demonstrate a novel and efficient pathway for extracellular electron transfer.The microbes use these conductive nanowires to transfer electrons over long distances,from the cell surface to the surface of extracellular electron acceptors(such as Fe(Ⅲ) oxides and electrodes),overcoming the requirement of direct physical contact between microbes and electron acceptors.The discovery of microbial nanowires has advanced our understanding of extracellular respiration and the diversity of microbial respiratory systems in nature.It has great significances for electricity production of microbial fuel cell,degradation of organic pollutants and bioenergy generation.Moreover,it will help us to develop the advanced materials and micromodule equipments in the emerging field of nanotechnology.In this review,we introduced the basic characteristics of microbial nanowires and the microorganisms capable of producing nanowires.The studies on their electron transfer mechanisms and applications in bioremediation and bioenergy are reviewed with an emphasis,and the prospects of key researches in the future are discussed.