title: Aeromonas hydrophila produces conductive nanowires.
abstract: Aeromonas hydrophila is a facultative anaerobe which, under conditions of oxygen depletion, uses Fe(III) as electron acceptor. A. hydrophila produces pili during growth with Fe(III). The study was focused on the characterization of the morphology, the electrical properties and the nature of the bacterial pili. Scanning electron microscopy and conductive-probe atomic force microscopy revealed the presence of filaments between cells and substrate and their conductive nature. Our results indicate that pili of A. hydrophila strain A might serve as biological nanowires, transferring electrons from the cell surface to the surface of Fe(III) oxides and, in addition, the possibility of playing a role in inter/intra species signaling. Quorum sensing (QS) is recognized as one of the main regulatory ways for extracellular polymeric substances (EPS) production and biofilm formation. We present evidence that nanowire formation can be regulated by addition of synthetic acyl-homoserine lactones (AHL). These conductive pili may be involved in various interactions, and their protein components might be usable in the future for biotechnological approaches in materials science.
authors.affiliation: Department of Materials Science and Metallurgical Engineering, Complutense University of Madrid, Av. Complutense s/n, 28040 Madrid, Spain. Electronic address: lcastror@ucm.es.
authors.forename: Laura
authors.initials: L
authors.lastname: Castro
authors.affiliation: Biofilm Centre, Aquatic Biotechnology, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Vera
authors.affiliation: Department of Materials Science and Metallurgical Engineering, Complutense University of Madrid, Av. Complutense s/n, 28040 Madrid, Spain.
authors.forename: Jesús Ángel
authors.initials: JÁ
authors.lastname: Muñoz
authors.affiliation: Department of Materials Science and Metallurgical Engineering, Complutense University of Madrid, Av. Complutense s/n, 28040 Madrid, Spain.
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Blázquez
authors.affiliation: Department of Materials Science and Metallurgical Engineering, Complutense University of Madrid, Av. Complutense s/n, 28040 Madrid, Spain.
authors.forename: Felisa
authors.initials: F
authors.lastname: González
authors.affiliation: Biofilm Centre, Aquatic Biotechnology, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Sand
authors.affiliation: Department of Materials Science and Metallurgical Engineering, Complutense University of Madrid, Av. Complutense s/n, 28040 Madrid, Spain. Electronic address: ambape@ucm.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ballester
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism; D016980:Aeromonas hydrophila / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D004553:Electric Conductivity; D004783:Environmental Microbiology; D005290:Ferric Compounds / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D053770:Nanowires / Q000382:microbiology*; D053038:Quorum Sensing
chemical_list: D054742:Acyl-Butyrolactones; D005290:Ferric Compounds; C000499:ferric oxide
keywords: AHL; Biofilms; Cell attachment; Conductive-AFM; Iron reducing bacteria