vpsA- and luxO-independent biofilms of Vibrio cholerae.
The natural life cycle of Vibrio cholerae involves the transitioning of cells between different environmental surfaces such as the chitinous shell of Crustaceae and the epithelial layer of the human intestine. Previous studies using static biofilm systems showed a strict dependence of biofilm formation on the vps and lux genes, which are essential for exopolysaccharide formation and cell-cell signaling, respectively. The authors' report here that in biofilms grown under hydrodynamic conditions, DeltavpsA and DeltaluxO mutants of V. cholerae do form pronounced, three-dimensional biofilms that resemble all aspects of wild-type biofilms. By genetic experiments, it was shown that in hydrodynamically grown biofilms this independence of vpsA is due to the expression of rpoS, which is a negative regulator of vpsA expression. Biofilms also underwent substantial dissolution after 96 h that could be induced by a simple stop of medium flow. The studies indicate that metabolic conditions control the reversible attachment of cells to the biofilm matrix and are key in regulating biofilm cell physiology via RpoS. Furthermore, the results redefine the roles of vps and quorum-sensing in V. cholerae biofilms.
Müller
Jana
J
Department of Civil & Environmental Engineering, Stanford University, Stanford, CA, USA.
Miller
Michael C
MC
Nielsen
Alex T
AT
Schoolnik
Gary K
GK
Spormann
Alfred M
AM
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development*; D003470:Culture Media; D015964:Gene Expression Regulation, Bacterial; D018613:Microscopy, Confocal; D009154:Mutation; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014734:Vibrio cholerae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure
D001426:Bacterial Proteins; D003470:Culture Media; C088907:LuxO protein, Vibrio harveyi; D012097:Repressor Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C069567:sigma factor KatF protein, Bacteria