Slower growth of Escherichia coli leads to longer survival in carbon starvation due to a decrease in the maintenance rate
Authors: Severin Josef Schink
Elena Biselli
Ulrich Gerland
Journal: Molecular systems biology (2020)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: bacterial fitness; bacterial survival; bacterial systems biology; death rate; quantitative physiology.
Affiliations: Physics of Complex Biosystems, Physics Department, Technical University of Munich, Garching, Germany., Department of Systems Biology, Harvard Medical School, Boston, MA, USA.

Abstract:  Fitness of bacteria is determined both by how fast cells grow when nutrients are abundant and by how well they survive when conditions worsen. Here, we study how prior growth conditions affect the death rate of Escherichia coli during carbon starvation. We control the growth rate prior to starvation either via the carbon source or via a carbon-limited chemostat. We find a consistent dependence where death rate depends on the prior growth conditions only via the growth rate, with slower growth leading to exponentially slower death. Breaking down the observed death rate into two factors, maintenance rate and recycling yield, reveals that slower growing cells display a decreased maintenance rate per cell volume during starvation, thereby decreasing their death rate. In contrast, the ability to scavenge nutrients from carcasses of dead cells (recycling yield) remains constant. Our results suggest a physiological trade-off between rapid proliferation and long survival. We explore the implications of this trade-off within a mathematical model, which can rationalize the observation that bacteria outside of lab environments are not optimized for fast growth. 

Retracted: No

PubPeer comments:
 Dear Authors, While reading your paper (that I actually liked very much!), I noticed several inconsistencies between the reported slopes in the main text and the ones shown in the figures (or the corresponding legends). Sometimes the differences are small and might be just due to rounding, in other cases; however, they are more sever. For example: - In the text on p. 2, the slope of the (exponential) fit is described as **0.87** +- 0.13 h, while in the corresponding figure 1C it is **0.88** +- 0.13 h - Text p. 4 on the bottom, the slope of Fig 2F (the text states 2E, but this should be 2F) is **0.78** +- **0.35** h, while it is **0.75** +- **0.39** h in the figure - Text p. 4 right column, the slope of Fig 2J is **1.88** +- **0.56** h while it is **2.03** +- **0.53** h in the figure - p. 5 for Fig 3A: - Length slope in text 0.23 +- **0.18** h, in the figure 0.23 +- **0.03** h - Width slope in text **0.32** +- **0.21** h, in the figure **0.33** +- **0.03** h (this is an especially large difference in the standard deviation!) - p. 5 for Fig 3D: in text a slope of **1.0** +- **0.5** h, in the figure **1.16** +- **0.48** h - p. 6 for Fig 4: WT slope in text **0.87** +- 0.13 h, in the figure legend **0.88** +- 0.13 h I believe that the absolute numbers do not change any of the conclusions in the paper, but I am still wondering which numbers are correct and where this differences come from. Also, on p. 6, right column, there is a mentioning that the dashed line in Fig 5B represents the function for u03bc*, however I think they meant the solid line. In the next line, they mention an example with T+ = 3 h and T- = 3 d that should correspond to u03bc = 0.86 h. However using the graph in Fig 5B, these values for T+ and T- (T- T+ = 24) should correspond to a u03bc of about 1.5 h Could the authors clarify? Thanks! , 
 The journal has been in communication with the authors and a corrigendum is forthcoming. ,