title: Global impact of mature biofilm lifestyle on Escherichia coli K-12 gene expression.
abstract: The formation of biofilm results in a major lifestyle switch that is thought to affect the expression of multiple genes and operons. We used DNA arrays to study the global effect of biofilm formation on gene expression in mature Escherichia coli K-12 biofilm. We show that, when biofilm is compared with the exponential growth phase, 1.9% of the genes showed a consistent up- or downregulation by a factor greater than two, and that 10% of the E. coli genome is significantly differentially expressed. The functions of the genes induced in these conditions correspond to stress response as well as energy production, envelope biogenesis and unknown functions. We provide evidence that the expression of stress envelope response genes, such as the psp operon or elements of the cpx and rpoE pathways, is a general feature of E. coli mature biofilms. We also compared biofilm with the stationary growth phase and showed that the biofilm lifestyle, although sharing similarities with the stationary growth phase, triggers the expression of specific sets of genes. Using gene disruption of 54 of the most biofilm-induced genes followed by a detailed phenotypic study, we validated the biological relevance of our analysis and showed that 20 of these genes are required for the formation of mature biofilm. This group includes 11 genes of previously unknown function. These results constitute a comprehensive analysis of the global transcriptional response triggered in mature E. coli biofilms and provide insights into its physiological signature.
authors.affiliation: Groupe de génétique des biofilms-CNRS URA 2172, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex 15, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Beloin
authors.forename: Jaione
authors.initials: J
authors.lastname: Valle
authors.forename: Patricia
authors.initials: P
authors.lastname: Latour-Lambert
authors.forename: Philippe
authors.initials: P
authors.lastname: Faure
authors.forename: Mickaël
authors.initials: M
authors.lastname: Kzreminski
authors.forename: Damien
authors.initials: D
authors.lastname: Balestrino
authors.forename: Janus A J
authors.initials: JA
authors.lastname: Haagensen
authors.forename: Søren
authors.initials: S
authors.lastname: Molin
authors.forename: Gérard
authors.initials: G
authors.lastname: Prensier
authors.forename: Brigitte
authors.initials: B
authors.lastname: Arbeille
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Ghigo
mesh_terms: D018441:Biofilms; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D013223:Statistics as Topic