Precision and variability in bacterial temperature sensing.

Area of Science:

• Microbiology
• Biophysics
• Systems Biology

Background:

• The ratio of Tar/Tsr chemoreceptors in Escherichia coli is crucial for bacterial taxis.
• This ratio varies with growth conditions and influences bacterial environmental responses.

Purpose of the Study:

• To quantitatively link the Tar/Tsr ratio to the preferred temperature of E. coli in thermal gradients.
• To understand how individual receptor response functions contribute to the population's overall thermal behavior.

Main Methods:

• Deducing individual receptor response functions from steady-state density profiles.
• Developing a model based on linear combinations of independent receptor responses.
• Comparing model predictions with experimental measurements of bacterial density profiles.

Main Results:

• Established a quantitative relationship between the Tar/Tsr ratio and favored temperature in wild-type E. coli.
• Demonstrated that bacterial density profiles accurately reflect the distribution of Tar/Tsr ratios.
• Showed that subpopulations with distinct Tar/Tsr ratios exhibit Gaussian distributions centered on specific favored temperatures.

Conclusions:

• The Tar/Tsr ratio is a key determinant of bacterial favored temperature in thermal gradients.
• Bacterial population behavior in temperature gradients can be predicted by analyzing the distribution of Tar/Tsr ratios.
• Individual receptor properties and their relative abundance govern the collective thermal response of E. coli populations.