Today - Quantitative Life Sciences guest seminar

[Quantitative Life Sciences]

*_ Quantitative Life Sciences Guest Semina__r:_

*Monday 15 May at 14:30
ICTP, Central Area, 2nd floor, old SISSA building, Via Beirut

Title: " Bacterial finite-size effects for population expansion under flow"

Speaker: Federico Toschi, Technische Universiteit Eindhoven, The Netherlands

Abstract:
For organisms living in a liquid ecosystem, flow and flow gradients have 
a dual role as they transport nutrient while, at the same time, 
dispersing the individuals. In absence of flow and under homogeneous 
conditions, the growth of a population towards an empty region is 
usually described by a reaction-diffusion equation. The effect of fluid 
flow is not yet well understood and the interplay between transport of 
individuals and growth opens a wide scenario of possible behaviors. In 
this work, we study experimentally the dynamics of non-motile E. coli 
bacteria colonies spreading inside rectangular channels, in PDMS 
microfluidic devices. By use of a fluorescent microscope we analyze the 
dynamics of the population density subjected to different co- and 
counter-flow conditions and shear rates. A simple model incorporating 
growth, dispersion and drift of finite size beads is able to explain the 
experimental findings. This indicates that models based on the 
Fisher-Kolmogorov-Petrovsky-Piscounov equation (FKPP) may have to be 
supplemented with bacterial finite-size effects in order to be able to 
accurately reproduce experimental results for population spatial growth.

Erica Sarnataro
Group Secretary
Quantitative Life Sciences
The Abdus Salam International Centre for Theoretical Physics (ICTP)
Trieste,  Italy
Tel. +39-040-2240623
e-mail:qls at ictp.it