Electrokinesis is a microbial behavior that requires extracellular electron transport
Electrokinesis is a microbial behavior that requires extracellular electron transport
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DOI：
10.1073/pnas.0907468107
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发表时间：
2010-01-05
影响因子：
11.1
通讯作者：
Nealson, K. H.
中科院分区：
文献类型：
--
作者：
Harris, H. W.;El-Naggar, M. Y.;Nealson, K. H.
我们报告了一种以前未描述的细菌行为，称为电动。这种行为最初被观察到作为一个显着增加的细胞游泳速度在减少固体二氧化锰颗粒的异化金属还原细菌希瓦氏菌oneidensis MR-1。当细胞暴露于微电化学电池的工作电极处的小的正施加电位时，观察到相同的行为反应，并且可以通过调节工作电极上的电位来调节。动电被认为是不同的趋化性和趋电性，但在突变体中缺乏缺陷的电子传递到固体金属氧化物。使用原位视频显微镜和细胞跟踪算法，我们已经量化了不同希瓦氏菌菌株的响应，并表明该响应与微生物燃料电池中的电流产生能力相关。电动响应仅由最接近MnO 2颗粒或电极的细胞亚群表现出。相比之下，添加1 mM 9，10-蒽醌-2，6-二磺酸（一种可溶性电子穿梭剂）导致整个群体的运动性增加。电致动被定义为需要功能性细胞外电子传递的行为反应，并且被观察为在氧化还原活性矿物表面或电化学电池的工作电极附近发生的细胞游泳速度的增加和运动路径的延长。
We report a previously undescribed bacterial behavior termed electrokinesis. This behavior was initially observed as a dramatic increase in cell swimming speed during reduction of solid MnO2 particles by the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1. The same behavioral response was observed when cells were exposed to small positive applied potentials at the working electrode of a microelectrochemical cell and could be tuned by adjusting the potential on the working electrode. Electrokinesis was found to be different from both chemotaxis and galvanotaxis but was absent in mutants defective in electron transport to solid metal oxides. Using in situ video microscopy and cell tracking algorithms, we have quantified the response for different strains of Shewanella and shown that the response correlates with current-generating capacity in microbial fuel cells. The electrokinetic response was only exhibited by a subpopulation of cells closest to the MnO2 particles or electrodes. In contrast, the addition of 1 mM 9,10-anthraquinone-2,6-disulfonic acid, a soluble electron shuttle, led to increases in motility in the entire population. Electrokinesis is defined as a behavioral response that requires functional extracellular electron transport and that is observed as an increase in cell swimming speeds and lengthened paths of motion that occur in the proximity of a redox active mineral surface or the working electrode of an electrochemical cell.