Role of space filling in pattern formation in bacterial biofilms

Pattern formation during bacterial community growth plays a crucial role in understanding the development of biofilms, which are known to significantly contribute to antibiotic resistance. Biofilm formation is a multi-step process, and studying the patterns that emerge during bacterial growth is essential for understanding this phenomenon. Previously, experimental methods using granular hydrogel matrices were employed to study specific cases of bacterial growth and morphodynamics in three dimensions. Additionally, mathematical models such as the Monod model have been used to develop 3D models of bacterial colonies. However, there is a lack of simulations and experiments that predict the complex patterns formed by bacterial colonies.

In this study, we show that the complex patterns that arise during bacterial swimming can be described by simple relationships that depend on the expansion rates of individual cells and spatial exclusion. We first model these complex patterns in two dimensions and verify them experimentally using the bacterium Vibrio cholerae. We then extend the model to three dimensions, validating it with a gut microbial model. Our data suggest that these complex patterns are predictable and can be driven by space constraints.This has important implications for understanding the spatial organization of microbial communities, where biofilm formation and bacterial interactions can influence disease progression, and the effectiveness of antibiotic treatments.