JB Accepts, published online ahead of print on 2 November 2007

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Valle, J. Articles by Ghigo, J.-M. Search for Related Content PubMed PubMed Citation Articles by Valle, J. Articles by Ghigo, J.-M.

 Previous Article  |  Next Article 

J. Bacteriol. doi:10.1128/JB.01405-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

The amino-acid valine is secreted in continuous-flow bacterial biofilms

Jaione Valle, Sandra Da Re, Solveig Schmid, David Skurnik, Richard D'Ari, and Jean-Marc Ghigo^*

Unité de Génétique des Biofilms, Institut Pasteur (CNRS URA 2172), 25 rue du Dr. Roux, 75724 Paris CEDEX 15, France; INSERM U722; Université Paris 7 Denis Diderot, Faculté de Médecine Xavier Bichat, 75018 Paris, France; EA 3964, Université Paris 7 Denis Diderot, Faculté de Médecine Xavier Bichat, 75018 Paris, France; Institut Jacques Monod, CNRS, Université Paris 6, Université Paris 7, 75251 Paris, CEDEX 05, France

^* To whom correspondence should be addressed. Email: jmghigo{at}pasteur.fr.

Biofilms are structured communities characterized by distinctive gene expression patterns and profound physiological changes as compared to planktonic cultures. Here, we show that many Gram-negative bacterial biofilms secrete high levels of a small molecular weight compound, which only inhibits the growth of the Escherichia coli K12 and of rare few other natural isolates. We demonstrate both genetically and biochemically that this molecule is the amino acid valine, and we provide evidence that valine production within biofilms results from metabolic changes occurring within high density biofilm communities when carbon sources are not limiting. This finding identifies a natural environment in which bacteria can encounter high amounts of valine and we propose that in biofilm valine secretion may be the long-sought reason for widespread but unexplained valine resistance found in most enterobacteria. Our results experimentally validate the postulated production of metabolites that are characteristics of the conditions associated with some biofilm environments. The identification of such molecules may lead to new approaches for biofilm monitoring and control.

This article has been cited by other articles:

• Kim, W., Levy, S. B. (2008). Increased Fitness of Pseudomonas fluorescens Pf0-1 Leucine Auxotrophs in Soil. Appl. Environ. Microbiol. 74: 3644-3651 [Abstract] [Full Text]