Farzan Beroz this Thursday @ 11:30

[Leenoy Meshulam]

Hi all,

This week we will hear from Farzan beroz from Ned Wingreen’s group about “Isobaricity and dynamical heterogeneity in bacterial biofilms”. Below please find the abstract.

Seminar starts at 11:30 am, room 200 as usual.

 

Leenoy

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Isobaricity and dynamical heterogeneity in bacterial biofilms/ Farzan beroz

Biofilms are groups of bacteria that adhere to and grow on surfaces. Recent advances in imaging technology allowed entire Vibrio cholerae biofilms to be observed at single-cell resolution in real time, revealing a growth program consisting of several architectural transitions. These early observations showed that cells are not arranged randomly within a colony, but instead grow from a branched, two-dimensional layer of founder cells into a three-dimensional structure with a vertically-aligned core. Here, we elucidate the physical mechanism of this transition using a combination of agent-based and continuum modeling. We find that the competing effects of cell growth and cell verticalization give rise to an exotic mechanical state in which the pressure becomes constant throughout the entire growing core of the colony. This “dynamical isobaricity” sets the velocity of surface expansion and thereby regulates how cells access the third dimension. In particular, our theory predicts that a longer average cell length yields faster expanding, flatter colonies. We experimentally observe such changes in colony development by using drugs to perturb cell length.