title: Fitness Trade-Offs in Competence Differentiation of Bacillus subtilis.
abstract: In the stationary phase, Bacillus subtilis differentiates stochastically and transiently into the state of competence for transformation (K-state). The latter is associated with growth arrest, and it is unclear how the ability to develop competence is stably maintained, despite its cost. To quantify the effect differentiation has on the competitive fitness of B. subtilis, we characterized the competition dynamics between strains with different probabilities of entering the K-state. The relative fitness decreased with increasing differentiation probability both during the stationary phase and during outgrowth. When exposed to antibiotics inhibiting cell wall synthesis, transcription, and translation, cells that differentiated into the K-state showed a selective advantage compared to differentiation-deficient bacteria; this benefit did not require transformation. Although beneficial, the K-state was not induced by sub-MIC concentrations of antibiotics. Increasing the differentiation probability beyond the wt level did not significantly affect the competition dynamics with transient antibiotic exposure. We conclude that the competition dynamics are very sensitive to the fraction of competent cells under benign conditions but less sensitive during antibiotic exposure, supporting the picture of stochastic differentiation as a fitness trade-off.
authors.affiliation: Department of Physics, University of Cologne Köln, Germany.
authors.forename: Melih
authors.initials: M
authors.lastname: Yüksel
authors.affiliation: Department of Physics, University of Cologne Köln, Germany.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Power
authors.affiliation: Department of Physics, University of Cologne Köln, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Ribbe
authors.affiliation: Department of Physics, University of Cologne Köln, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Volkmann
authors.affiliation: Department of Physics, University of Cologne Köln, Germany.
authors.forename: Berenike
authors.initials: B
authors.lastname: Maier
keywords: antibiotic tolerance; competence; fitness; persistence; phenotypic heterogeneity