A Universal Geometric Principle of Spatial Organization in Bacterial Populations

Spatial organization is a key feature of living systems, yet the principles that govern bacterial collective order remain unclear. Microbial pattern formation has been attributed to microbe-specific processes such as chemotaxis, nutrient transport, and signaling. However, similar patterns are observed across phylogenetically distant species and conditions, suggesting a universal organizing principle. We show that bacterial communities expand according to the Voronoi growth method, which achieves spatial organization through geometric ordering that maximizes space-filling efficiency. Using Vibrio cholerae, Pseudomonas aeruginosa, and Escherichia coli as model systems, we demonstrate that bacterial populations expand into Voronoi tessellations that arise solely from radial growth and contact inhibition. Entropic analysis reveals that pattern formation introduces no additional entropy beyond the initial configuration, indicating that organization is fully determined by initial conditions and environmental constraints. These findings establish geometric ordering as a universal organizing principle in bacteria and demonstrate that bacterial community organization can be determined without invoking details of microbe-specific processes. Importantly, the work bridges bacterial pattern formation with the geometric principles observed in multicellular systems.