Size of quorum sensing communities

Jesper Ferkinghoff-Borg, Thomas Sams

    Research output: Contribution to journalJournal articleResearchpeer-review

    633 Downloads (Pure)


    Ensembles of bacteria are able to coordinate their phenotypic behavior in accordance with the size, density, and growth state of the ensemble. This is achieved through production and exchange of diffusible signal molecules in a cell–cell regulatory system termed quorum sensing. In the generic quorum sensor a positive feedback in the production of signal molecules defines the conditions at which the collective behavior switches on. In spite of its conceptual simplicity, a proper measure of biofilm colony ‘‘size’’ appears to be lacking. We establish that the cell density multiplied by a geometric factor which incorporates the boundary conditions constitutes an appropriate size measure. The geometric factor is the square of the radius for a spherical colony or a hemisphere attached to a reflecting surface. If surrounded by a rapidly exchanged medium, the geometric factor is divided by three. For a
    disk-shaped biofilm the geometric factor is the horizontal dimension multiplied by the height, and the square of the height of the biofilm if there is significant flow above the biofilm. A remarkably simple factorized expression for the size is obtained, which separates the all-or-none ignition caused by the positive feedback from the smoother activation outside the switching region.
    Original languageEnglish
    JournalMolecular BioSystems
    Issue number103
    Pages (from-to)103-109
    Publication statusPublished - 2014


    Dive into the research topics of 'Size of quorum sensing communities'. Together they form a unique fingerprint.

    Cite this