INVESTIGADORES
RAPISARDA Viviana Andrea
congresos y reuniones científicas
Título:
PhoB modulation by polyphosphate levels in Escherichia coli and its involvement in biofilm formation
Autor/es:
GRILLO-PUERTAS, M.; RINTOUL, M. R.; RAPISARDA, V. A.
Reunión:
Congreso; LI Annual Meeting of SAIB (Argentine Society for Biochemistry and Molecular Biology); 2015
Resumen:
Polyphosphate (polyP) in Escherichia coli stationary phase is modulated by the media phosphate (Pi) concentration and its degradation induces biofilm formation via LuxS quorum sensing system. PhoB, the regulator of the two component system phoBR, responds to media Pi limitation and inhibits biofilm formation. The aim of this work was to investigate if PhoB is implicated in the formerly studied biofilm formation regulated by fluctuations in polyP levels. Cells were statically grown at 30ºC in minimal medium varying Pi concentration (0.003, 2 and 40 mM). Alkaline phosphatase (AP) activity was measured as an indicator of PhoB activity. In stationary phase, a high AP activity was observed when polyP was accumulated, while it was similar to that of phoB mutant when polyP was degraded or absent. Consequently, when PhoB is repressed (polyP degradation) or absent (phoB related-mutants) cells form biofilm independently of the media Pi concentration, indicating that PhoB inhibits biofilm formation in a polyP accumulating condition. Data shows that PhoB activity is modulated in non-limiting Pi condition by fluctuation in polyP. PhoB seems to be a component in the signal cascade that regulates biofilm formation triggered by polyP levels in stationary phase.