Berlin 2018 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 18: Focus Session: Physics of Microbial Systems - organized by Tobias Bollenbach and Benedikt Sabass

BP 18.4: Vortrag

Mittwoch, 14. März 2018, 10:30–10:45, H 2013

Dormant, dead or alive: measuring steady state free energy levels in bacterial cells — •Leonardo Mancini and Teuta Pilizota — University of Edinburgh

Bacteria can survive a variety of external stresses by entering a state of suspended growth that is commonly referred to as dormancy. Such response has historically been considered a unequivocal low metabolism-low energy state and a vast array of stressors seem to be avoidable through dormancy. Antibiotics are among the most notable examples of such stressors and tolerant, dormant cells are known as persisters. However, recent experiments show that some persisters might survive antibiotic challenges through mechanisms that are, in contrast, energy consuming. The findings open the possibility of several different dormant steady states with distinct cellular free energy levels. To verify such a hypothesis, molecular sensors that can provide information on cellular energetics in vivo and at the single cell level are needed. To this end, we have successfully optimized the expression of a previously reported QUEEN ATP sensor and characterized in E. coli the newly proposed membrane voltage dye, Thioflavin T. Our results provided insights that can be generalized to other dyes, such as TMRM and DiSC3(5). Using the sensors, we present measurements of free energy levels during dormancy when this is induced by different conditions and signals, such as starvation, quorum sensing, and stress signalling molecules.