Jan 29, 2024

The intrinsic microbial response to temperature fluctuations

Date: January 29, 2024 | 3:30 pm – 4:30 pm
Speaker: Kerwyn C Huang, Stanford
Location: Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101)
Language: English

The impact of temperature on growth is typically considered only under heat- or cold-shock conditions that elicit specific regulation. Over intermediate temperatures, the growth rate of all cells varies according to the Arrhenius law of thermodynamics; growth rate dynamics during transitions between temperatures remain mostly unstudied. How this behavior arises and what determines temperature sensitivity are largely unknown. Using a device that enables single-cell tracking during switches across a wide range of temperatures (0 °C to 47 °C), we show that many bacteria respond to temperatures upshifts on a characteristic time scale of ~1.6 doublings at the higher temperature, regardless of initial/final temperature or nutrient source. We rule out transcriptional, translational, and membrane reconfiguration as potential mechanisms, and instead discover that an autocatalytic enzyme network incorporating temperature-sensitive Michaelis-Menten kinetics recapitulates all temperature-shift dynamics and successfully predicts the altered temperature responses observed under simple-sugar and low-nutrient growth conditions. These findings suggest that the temperature sensitivity of metabolite flux dictates responses to temperature fluctuations.