title: Significance of rpoS during maturation of Escherichia coli biofilms.
abstract: Presence of starved, stationary phase-like zones in biofilms seems to be an important factor for biofilm formation. In this study, roles of rpoS gene in the formation of Escherichia coli biofilms were investigated. E. coli MG1655 wild type (WT) and rpoS mutant (DeltarpoS) strains were used to compare biofilm formation capacity and global gene expression. Even though the DeltarpoS strain could attach and form microcolonies on glass surfaces, it could not establish mature biofilms. DNA microarray analysis revealed that WT biofilms (WBF) showed similar pattern of gene expression with WT planktonic stationary phase, whereas DeltarpoS biofilms (MBF) showed similar pattern of gene expression with WT planktonic exponential phase. Genes involved in energy metabolism (atpIBEFHAG, atpC, cydAB) and flagella synthesis (flgB, flgC, flhD, fliA, fliC, fliY) showed increased expression in the MBF, but not in the WBF. Moreover, genes involved in stress responses (blc, cspG, dinD poxB, wcaF, wcaI, and yfcF) showed increased expression in the WBF compared to the MBF. These results suggested that the rpoS gene contributed in maturation of E. coli biofilms through regulation of global gene expression including energy metabolism, motility, and stress responses.
authors.affiliation: Department of Urban and Environmental Engineering, Graduate School of Engineering, Hokkaido University, North-13, West-8, Sapporo 060-08628, Japan.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Ito
authors.forename: Thithiwat
authors.initials: T
authors.lastname: May
authors.forename: Koji
authors.initials: K
authors.lastname: Kawata
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okabe
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D002448:Cell Adhesion / Q000502:physiology; D049109:Cell Proliferation; D004734:Energy Metabolism / Q000502:physiology; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D012808:Sigma Factor / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria