Dresden 2017 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 29: Posters - Multi-Cellular Systems

BP 29.4: Poster

Dienstag, 21. März 2017, 14:00–16:00, P2-EG

Coalescence of bacterial microcolonies reveals liquid-like dynamics — •Tom Cronenberg, Enno R. Oldewurtel, Nadzeya Kouzel, and Berenike Maier — Department of Physics, University of Cologne, 50539 Cologne, Germany

Many bacteria are able to form communities called microcolonies. Within these structured communities they benefit from various advantages including facilitated gene transfer and increased antibiotic resistance. The human pathogen Neisseria gonorrhoeae is able to aggregate into spherical microcolonies due to active retraction of its type 4 pili, which is the first step of biofilm formation. Once two microcolonies are within a minimal range, an actively driven fusion process is initiated. To test if the fusion of microcolonies shows liquid-like dynamics, we acquired time lapsed microscopy data of newly formed microcolonies in liquid environment. The contour of fusing colonies was extracted and fitted by an ellipse to calculate the ratio between minor and major axis. According to a model developed by Young, the deformation of a liquid droplet from an ellipse to a sphere is driven by surface tension σ and resisted by viscosity η. Therefore, we used Young’s model to characterize the spatio-temporal dynamics of colony fusions quantitatively by calculating the ratio σ/η.