Quorum sensing detected by atomic force microscopy imaging of corrals surrounding multicellular arrangement of bacteria

Abstract

Connectivity of the glycocalyx covering of small communities of Acidithiobacillus ferrooxidans bacteria deposited on hydrophilic mica plates was imaged by atomic force microscopy. When part of the coverage was removed by water rinsing, an insoluble structure formed by corrals surrounding each individual bacterium was observed. A collective ring structure with clustered bacteria (>or=3) was observed, which indicates that the bacteria perceived the neighborhood in order to grow a protective structure that results in smaller production of exopolysaccharides material. The most surprising aspect of these collective corral structures was that they occur at a low bacterial cell density. The deposited layers were also analyzed by confocal Raman microscopy and shown to contain polysaccharides, protein, and glucoronic acid.

Imaging and Characterization of Self-Assembled Soft Nanostructures

“…The EPS normal composition depends on the microbial species, the physiological conditions involved and a number of environmental factors [22,23]. Even in low cell densities, the cooperation enhances the A. ferrooxidans effectiveness of attaching and covering the mica substrate during bacteria dispersion drying [26]. 3).…”