Aeromonas hydrophila produces conductive nanowires

• Published in: Research in microbiology 2014-11, Vol.165 (9), p.794-802
• Main Authors: Castro, Laura, Vera, Mario, Muñoz, Jesús Ángel, Blázquez, María Luisa, González, Felisa, Sand, Wolfgang, Ballester, Antonio
• Format: Article
• Language: English
• Subjects: Acyl-Butyrolactones - metabolism; Aeromonas hydrophila; Aeromonas hydrophila - metabolism; Aeromonas hydrophila - physiology; Aeromonas hydrophila - ultrastructure; AHL; Biofilms; Cell attachment; Conductive-AFM; Electric Conductivity; Environmental Microbiology; Ferric Compounds - metabolism; Fimbriae, Bacterial - ultrastructure; Iron reducing bacteria; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Nanowires - microbiology; Quorum Sensing
• ISSN: 0923-2508; 1769-7123
• DOI: 10.1016/j.resmic.2014.09.005

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.