Dresden 2017 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 4: Systems Biology & Gene Expression and Signalling
BP 4.2: Vortrag
Montag, 20. März 2017, 15:30–15:45, ZEU 250
Origin and consequences of the exponential decay of viability of Escherichia coli during starvation — •Severin Schink1, Elena Biselli1, Constantin Ammar1,2, and Ulrich Gerland1 — 1Technische Universität München, Physik Department — 2Ludwig-Maximilians-Universität München, Institut für Informatik
Surviving nutrient limitation is an important part of the microbial life cycle. When carefully starved of all energetic substrates, Escherichia coli shows an exponential decay of viability, with the rate depending on environment and genetics. In this work we identify the exponential decay to be a consequence of the energetic needs of the cell for maintenance. When no carbon resources are available in the medium, the only external possibility for energy production are resources freed by lysed cells in the population. Such a cannibalistic process, in which dying cells release resources that can sustain the remaining live cells, naturally leads to an exponential decay of viability. The death rate of a starved population is thus a measure for the maintenance rate, and allows quantitative studies of environmental and genetic perturbation, as exemplified by the study of knock-outs of the stress response sigma factor rpoS.