Berlin 2015 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 22: Evolutionary Game Theory II (joint session SOE/ BP/ DY)

DY 22.5: Vortrag

Dienstag, 17. März 2015, 15:00–15:15, MA 001

The Cost and Dynamics of Competence in Bacillus subtilis — •Jeffrey Power, Melih Yüksel, and Berenike Maier — Universität zu Köln, Cologne, Germany

When bacterial cells deplete all of the nutrients in their environment, they can enter a stationary growth phase. In Bacillus subtilis, the stationary phase is of particular interest as a fraction of a culture in the stationary phase will stochastically switch into a competent state, where cells can take up extracellular DNA. Competence presents the opportunity for the acquisition and implementation of new genes, but at the cost of a reduced growth rate.

To better understand the advantage of stochastic switching, stationary phase competition assays were carried out competing strains with various fractions of competent cells against the wild type. Flow cytometry was used to monitor changes in the mixed populations over time, and fitness advantages were quantified by means of selection coefficients. We found selection coefficients of s = 0.04(1) for the noncompetent comK strain and s = -0.07(1) for the hypercompetent rok strain, indicating that competence development has a large cost.

This work is a fundamental start to better understanding the dynamics of the stationary phase and the evolutionary advantage of stochastically switching a population subset into a competent state.