Bacterial cells track chemical gradients in the environment, leading to variety adaptive behaviors. We study the sensory and computational properties underlying this behavior at the molecular, cellular, and population levels.
Sensory Perception
The chemosensory apparatus is a large, membrane-bound, array of sensory molecules.
To study how signals are perceived and processed within cells we use various microscopy techniques, including FRET and fluorescence anisotropy, that allow real-time detection within living bacterial cells of the physical and biochemical responses of the sensory molecules to external stimuli.
Mol. Microbiol. (2013); MBio (2016); PNAS (2016); PNAS (2024).
sub-cellular organization
The large, membrane-bound chemosensory array has a clear bias towards the cell pole, making is a notable case study for understanding basic concepts of cellular organization.
We have quantitatively studied the positioning dynamics of sensory arrays across generations, their nucleation and growth revealing two distinct groups of array behaviors.
Population dynamics and Collective behaviors
Ultimately, the chemosensory apparatus guides bacteria towards regions that they deem favourable. We study the migration of populations of bacteria in response to complex chemical signals using microscopy and a variety of assays that allows quantitative characterization of the bacterial behavioral responses.
Although chemotaxis is inherently a single-cell behavior, collective behaviors can emerge when bacteria modulate their chemical environment. In a recent project, we discovered that bacteria can collectively condense under uniform pH stress, facilitate formation of tightly packed communities and allows the bacterial to cope more efficiently with the stress.
