Visualization of Biosurfactant Film Flow in a Bacillus subtilis Swarm Colony on an Agar Plate

摘要: Collective bacterial dynamics plays a crucial role in colony development. Although many research groups have studied the behavior of fluidic swarm colonies, detailed mechanics its motion remains elusive. Here, we developed visualization method using submicron fluorescent beads for investigating flow field thin layer fluid that covers Bacillus subtilis growing on an agar plate. The were initially embedded plate and subsequently distributed spontaneously at upper surface expanding colony. We conducted long-term live cell imaging B. tracers, obtained high-resolution velocity maps microscale vortices particle image velocimetry. A distinct periodic fluctuation average speed vorticity was observed inner region colony, correlated with switch between swarming growth phases. At advancing edge both magnitudes inversely spreading edge. advanced tool this study would facilitate further understanding effect micro collective bacteria.