Link to bioRxiv paper:
http://biorxiv.org/cgi/content/short/2023.07.22.550177v1?rss=1
Authors: Knapp, B., Willis, L., Gonzalez, C., Vashistha, H., Touma, J. J., Tikhonov, M., Ram, J., Salman, H., Elias, J. E., Huang, K. C.
Abstract:
The impact of temperature on growth is typically considered under heat- or cold-shock conditions that elicit specific regulation. In between, cellular growth rate varies according to the Arrhenius law of thermodynamics. Here, we use growth-rate dynamics during transitions between temperatures to discover how this behavior arises and what determines the temperature sensitivity of growth. Using a device that enables single-cell tracking across a wide range of temperatures, we show that bacteria exhibit a highly conserved, slow response to temperatures upshifts with a time scale of ~1.5 doublings at the higher temperature, regardless of initial/final temperature or nutrient source. We rule out transcriptional, translational, and membrane reconfiguration as potential mechanisms. Instead, we demonstrate that an autocatalytic enzyme network incorporating temperature-sensitive Michaelis-Menten kinetics recapitulates all temperature-shift dynamics, reveals that import dictates steady-state Arrhenius growth behavior, and successfully predicts alterations in the upshift response observed under simple-sugar or low-nutrient conditions or in fungi. These findings indicate that metabolome rearrangement dictates how temperature affects microbial growth.
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