Single-molecule visualization of temperature adaptation in sub-cellular dynamics and organization across bacteria

Introduction

Most microorganisms lack homeothermic regulation, which subjects them to unpredictable fluctuations in environmental temperature. Nevertheless, many bacteria and archaea can grow across a large range of up to 40°C.

Biochemical Reactions and Temperature

Most biochemical reactions in bacteria occur in the highly crowded cytoplasm, constituting a complex and dynamic interaction network of a cell. Temperature affects the rate of both intra- and intermolecular reactions, and large-scale perturbations by temperature could be disastrous to cellular function, homeostasis, and sub-cellular organization.

Knowledge Gaps

It is still largely unknown how temperature affects the properties of the cytoplasm and what the consequences to cellular processes are. The driving hypothesis of this project is that bacteria can actively modulate their cytoplasmic state to avoid the detrimental effects of temperature fluctuations.

Methodology

To test this, I have established cutting-edge super-resolution single-molecule tracking tools to directly observe molecule dynamics in live bacteria in real time.

1. First, we will quantify the diffusion and activity of macromolecules and other probes as a function of temperature to uncover the changes in the cytoplasmic state.
2. Second, we will probe different bacteria growing at temperatures from 0°C up to 100°C to characterize evolutionary differences in the cytoplasmic dynamics and temperature scaling of reaction rates.
3. Finally, we will uncover mechanisms by which bacteria obtain different cytoplasmic properties.

Implications

Overall, these approaches will reveal how the cytoplasmic state in bacteria changes with temperature and how this contributes to cellular processes, which has significant implications on how microorganisms adapt to temperatures and what the limits of cellular life are.