Biofilms are surface-bound communities of single-celled organisms that, collectively, have many characteristics more commonly associated with multicellular organisms. These are fascinating model systems for multicellularity, because the organisms that form biofilms have no intrinsic obligation to be anything other than isolated, individual cells – yet, in biofilms, these organisms cooperate with other cells of the same and different species, and even different kingdoms. In addition, understanding biofilms is of great practical importance because they cause most persistent bacterial infections and can damage industry infrastructure.
In biofilms, extracellular polysaccharides form a matrix that structures the biofilm and adheres cells to each other. We want to understand this role of the matrix better by studying the early stages of biofilm formation, when cells transition from being isolated into being cooperative, and by characterizing the way a biofilm’s physical properties and effects on its environment change over the course of the biofilm life-cycle. For these studies, we use software for automated bacteria-identification, tracking, and analysis to study inter-bacterial cohesion and interactions with the surface. We are trying to identify the specific roles played by two extracellular materials, pel and psl. We are also trying to describe the dynamics of microcolony formation in terms of the physical interactions between cells.