title: Nanoelectronic Investigation Reveals the Electrochemical Basis of Electrical Conductivity in Shewanella and Geobacter.
abstract: The electrical conductivity measured in Shewanella and Geobacter spp. is an intriguing physical property that is the fundamental basis for possible extracellular electron transport (EET) pathways. There is considerable debate regarding the origins of the electrical conductivity reported in these microbial cellular structures, which is essential for deciphering the EET mechanism. Here, we report systematic on-chip nanoelectronic investigations of both Shewanella and Geobacter spp. under physiological conditions to elucidate the complex basis of electrical conductivity of both individual microbial cells and biofilms. Concurrent electrical and electrochemical measurements of living Shewanella at both few-cell and the biofilm levels indicate that the apparent electrical conductivity can be traced to electrochemical-based electron transfer at the cell/electrode interface. We further show that similar results and conclusions apply to the Geobacter spp. Taken together, our study offers important insights into previously proposed physical models regarding microbial conductivities as well as EET pathways for Shewanella and Geobacter spp.
authors: Mengning
authors: M
authors: Ding
authors: Hui-Ying
authors: HY
authors: Shiu
authors: Department of Earth Sciences and Biological Sciences, University of Southern California , Los Angeles, California 90089, United States.
authors: Shiue-Lin
authors: SL
authors: Li
authors: Calvin K
authors: CK
authors: Lee
authors: Gongming
authors: G
authors: Wang
authors: Hao
authors: H
authors: Wu
authors: Nathan O
authors: NO
authors: Weiss
authors: Thomas D
authors: TD
authors: Young
authors: Paul S
authors: PS
authors: Weiss
authors: Gerard C L
authors: GC
authors: Wong
authors: Department of Earth Sciences and Biological Sciences, University of Southern California , Los Angeles, California 90089, United States.
authors: Kenneth H
authors: KH
authors: Nealson
authors: Yu
authors: Y
authors: Huang
authors: Xiangfeng
authors: X
authors: Duan
mesh_terms: D001674:Bioelectric Energy Sources; D018441:Biofilms; D004553:Electric Conductivity; D004566:Electrodes; D004579:Electron Transport; D045302:Geobacter; D036103:Nanotechnology; D020592:Shewanella
keywords: bioelectrochemical system; bioelectronics; electrogenic bacteria; extracellular electron transfer; microbial electrochemistry; microbiome; nanoelectronics