Bacterial Pattern Formation in Response to the Stiffness of Substrates

접촉 표면의 강성 변화에 따른 박테리아의 군집 패턴

Animal cells show different behaviors in response to the mechanical properties of the substrates. We hypothesize that the rigidity of the substrates also affects the bacterial motility and controls the colony dynamics. It is found that the colony size of Escherichia colis and Bacillus subtilis grown on the agar plates is correlated with agarose gel concentrations and thus with the substrate rigidity. High- resolution microscopic imaging reveals that bacteria in single colonies form different aggregation patterns on the agar plates with varying gel concentration. We measured the apparent diffusion coefficients in the agarose gel plates made with different gel concentrations. Mathematical modeling and quantitative imaging of dye dispersion in the agar plates suggest that there is a close connection between the diffusion rate and the colony size. Nanoscale pore structures and kinetic constraints in the porous media may have an effect on bacterial colony dynamics.