Research in quantitative microbiology

Functional role of non-genetic variability

Throughout biology isogenic cell populations exhibit phenotypic diversity and collective behavior. These properties complicate the treatment of diseases and our mechanistic understanding of biology because they give rise to emergent behaviors that are not directly predicted from the structures and functions of proteins.

One of our major goals is to understand how phenotypic heterogeneity in isogenic populations affects complex functions such as chemical sensing, adaptation, motility; and how the balance between phenotypic heterogeneity and collective behavior shapes population performance. How do we quantify individual cell performance and trace it back to molecules? What is the origin of cell-to-cell differences in performances? To what extend such variability is under selection? How does the shape of such  distribution affects population success?

Computational principles of bacterial navigation

During navigation towards a signal source, directional changes by the organism result in changes in the signal it is likely to experience next. Thus, behavior feeds back onto the signal and the statistics of signal and behavior are intrinsically related. Using bacterial chemotaxis in E. coli as a model system we are trying to understand how such feedback shapes the statistics of behavior, signal, and performance during navigation of chemical gradients. Cells travel also in groups by communicating between themselves. We are examining how diversity modulate group migration.