Laboratorio de Bioelectroquímica, Area de electroquímica y corrosión, INTEMA (Conicet), Mar del plata, Argentina.
Phys Chem Chem Phys. 2013 Jul 7;15(25):10300-6. doi: 10.1039/c3cp50411e. Epub 2013 May 22.
Geobacter sulfurreducens bacteria grow on biofilms and have the particular ability of using polarized electrodes as the final electron acceptor of their respiratory chain. In these biofilms, electrons are transported through distances of more than 50 μm before reaching the electrode. The way in which electrons are transported across the biofilm matrix through such large distances remains under intense discussion. None of the two mechanisms proposed for explaining the process, electron hopping through outer membrane cytochromes and metallic like conduction through conductive PilA filaments, can account for all the experimental evidence collected so far. Aiming at providing new elements for understanding the basis for electron transport, in this perspective article we present a modelled structure of Geobacter pilus. Its analysis in combination with already existing experimental evidence gives support to the proposal of the "stepping stone" mechanism, in which the combined action of pili and cytochromes allows long range electron transport through the biofilm.
脱硫杆菌细菌在生物膜上生长，具有将极化电极作为其呼吸链的最终电子受体的特殊能力。在这些生物膜中，电子在到达电极之前通过超过 50 μm 的距离进行传输。电子通过如此大的距离在生物膜基质中传输的方式仍在激烈讨论中。到目前为止，为了解释这一过程而提出的两种机制，即通过外膜细胞色素的电子跳跃和通过导电 PilA 丝的类似金属的传导，都不能解释所有的实验证据。为了提供理解电子传输基础的新元素，在这篇观点文章中，我们提出了一种 Geobacter 菌毛的建模结构。对其进行的分析与已经存在的实验证据相结合，支持了“踏脚石”机制的提出，该机制认为菌毛和细胞色素的共同作用允许电子通过生物膜进行长距离传输。
