Influence of topology on bacterial social interaction

Abstract

The environmental topology of complex structures is used by Escherichia coli to create traveling waves of high cell density, a prelude to quorum sensing. When cells are grown to a moderate density within a confining microenvironment, these traveling waves of cell density allow the cells to find and collapse into confining topologies, which are unstable to population fluctuations above a critical threshold. This was first observed in mazes designed to mimic complex environments, then more clearly in a simpler geometry consisting of a large open area surrounding a square (250 ؋ 250 m) with a narrow opening of 10 -30 m. Our results thus show that under nutrientdeprived conditions bacteria search out each other in a collective manner and that the bacteria can dynamically confine themselves to highly enclosed spaces.

Bacterial metapopulations in nanofabricated landscapes

“…At the local scale, the balance between dispersive forces (J 0 ) and chemotaxis-based aggregation (J 1 ) is critically dependent on density (22). The oscillatory behavior of local density, which we learned from the 0D analysis (Fig.…”

Resource Patch Formation and Exploitation throughout the Marine Microbial Food Web

“…Recent advances in microfluidics (Whitesides et al 2001;Weibel et al 2007) have enabled detailed analyses of microbial ecology within complex microhabitats (Mao et al 2003;Park et al 2003;Keymer et al 2006;Marcos and Stocker 2006). We utilized microfluidic technology to generate microscale resource patches and investigated how three model compartments of the oceans' planktonic food web, representing key players in the microbial loop (Azam et al 1983), respond to a patchy habitat.…”

Microfluidic Detection of Multiple Heavy Metal Ions Using Fluorescent Chemosensors

“…The mask designs were created in AutoCAD (San Rafael, CA, USA) and printed on high-resolution transparency films (Han & All Tech., Seoul, Korea). 19 The dimensions of the fluidic channels were 300 m 150 m (width height). A master mold was made by spinning a layer (150 m) of epoxy-based negative-tone photoresist (Nano SU-9 2010, MicroChem, Newton, MA, USA) on a polished silicon waferat two different speeds (500 rpm for 5 s and 1500 rpm for 30 s).…”