Research in the Taute lab focusses on how bacteria navigate their environment at levels from individuals to whole colonies. The lab develops and uses high-throughput optical approaches to reveal bacterial navigation dynamics and decipher the underlying mechanisms.
High-throughput 3D tracking of swimming bacteria
We developed a method that enables simultaneous 3D tracking of dozens of individual swimming bacteria using a standard microbiological phase-contrast microscope (Taute et al., Nat. Comm. 2015). Not only can we now efficiently compare motility behaviors between strains and species, but we can detect and analyze individuality in behavior between genetically identical individuals. It turns out: bacterial twins are far from equal!
A key navigation phenomenon in bacteria is chemotaxis – the ability to climb chemical gradients. Chemotaxis allows bacteria to move towards sources of nutrients. They may also use chemical gradients as cues to localize preferred sites, e.g., sites of infection. To understand how bacteria navigate chemical gradients, we combined 3D tracking technology with microfluidically created chemical gradients (Grognot & Taute, Comm. Biol. 2021). Within minutes, we can collect 3D trajectories for thousands of individual navigating bacteria. The method enables us to determine the behavioral mechanisms different bacterial species employ to navigate their chemical environment and compare the chemotactic performance enabled by different behavioral strategies.
How do pathogens and symbionts navigate the host environment?
Many bacterial pathogens and symbionts use motility and chemotaxis in the process of colonizing their hosts. Cholera disease kills approximately 100,000 people each year. It is caused by the bacterium Vibrio cholerae colonizing the small intestine. Motility is a key virulence factor in this pathogen, but the underlying mechanisms are unknown. We recently used high-throughput 3D tracking to perform the first quantitative characterization of V. cholerae motility behaviors (Grognot et al., Appl. Environ. Microbiol. 2021). Now we are addressing how it adapts its motility behavior to the host environment.
Collective range expansions
Colonies of swimming bacteria can expand by performing chemotaxis on chemical gradients that they are creating themselves by consumption.
Investment in motility incurs a growth cost, thus bacteria are subject to a tradeoff between growth and motility. Recently, we showed that two species that differ substantially in how they allocate their resources between those two traits (one grows fast, the other swims fast) will spontaneously segregate in space and then coexist stably next to each other (Gude et al., Nature 2020). More generally, we are interested in how behaviors at the level of individuals give rise to spatiotemporal dynamics at the population level, connecting spatial scales that can be orders of magnitude apart.