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Abstract

Biofilms are a major bacterial lifestyle where cells form surface-attached aggregates embedded in a self-produced extracellular matrix. As a multicellular living active matter, biofilms exhibit emergent properties, including antibiotic resistance and mechanical robustness, which play critical roles in health and industrial contexts. A key driver behind the emergent properties of biofilms is heterogeneity, or cell-to-cell variability. In the first part of the talk, I will present a newly developed imaging platform that reveals significant phenotypic heterogeneity and spatial patterning in clonal Vibrio cholerae biofilms. By integrating imaging, genetics, and modeling, we show that this sorted pattern is driven by matrix-mediated differential interactions between cells and their local environments. Importantly, our results show that this heterogeneity and emergent pattern formation enhance the fitness of biofilm-forming cells, expanding the classical picture of the biofilm life cycle. In the second part, I address a longstanding question in the evolution of social behaviors in biofilms: how diffusible matrix production remains stable against exploitation by non-producers. We demonstrate that shared matrix components function as public goods and are vulnerable to exploitation, and stability of matrix production depends critically on biofilm spatial structure, exploitation radius, and flow conditions. Together, these results provide new insights into biofilms by highlighting the role of heterogeneity at both the phenotypic and genotypic levels.