Prof. Dr. Oskar Hallatschek
UC Berkeley

Abstract
Microbial communities often thrive in spatially confined environments, such skin pores or intestinal crypts. These microhabitats foster stable populations that contribute to the diversity and functionality of microbiomes. However, the impact of spatial constraints on microbial community assembly and evolution remains poorly understood. By monitoring and modeling microbial populations under controlled microfluidic confinement, we uncover a rich spectrum of dynamical patterns that are controlled by the competition between density-dependent outflow and population growth. Our findings reveal that passive diffusion, regulated by population density, can push a reproducing community to a jamming threshold - leading to a complete loss of mixing and intra-species competition. The emerging sensitivity to scale may be viewed as a rigorously quantifiable in vitro version of similar effects reported in the field of island biogeography, and underscores the need to control for scale in microbial ecology experiments. Systematic, flow-adjustable length scale variations may serve as a promising strategy to elucidate further scale-dependent tipping points and to rationally modulate the stability and resilience of microbial colonizers.

Biography
Oskar Hallatschek studied physics at the University of Heidelberg and ETH Zürich, and obtained his doctoral degree in theoretical biophysics in 2004 from the Freie Universität Berlin. In 2005, he moved to Harvard University to pursue postdoctoral research with Professor David Nelson and Sharad Ramanathan on experimental and theoretical evolution. In 2009, he started an independent Max Planck Research Group at the Max-Planck-Institut for Dynamics and Self-Organization in Göttingen. He moved back to the US in 2013 to start the "Biophysics and Evolutionary Dynamics'' lab as assistant professor at the University of California, Berkeley.

Location
Seminar Room, 0.125, Kussmaulallee 2
Location Details

Zoom
https://eu02web.zoom-x.de/j/65410255502?pwd=7Ba0PcNFkmCrc18PvSlEajZAoCxWId.1 
Meeting-ID: 654 1025 5502
Kenncode: 069864