Dynamic remodeling of microbial biofilms by functionally distinct exopolysaccharides.
Bottom Line: Conversely, Pel reduced effective cross-linking within the matrix.The wild-type biofilm decreased in effective cross-linking over time, which would be advantageous for the spreading and colonization of new surfaces.The exopolysaccharides were also found to have profound effects on the spatial organization and integration of P. aeruginosa in a mixed-species biofilm model of P. aeruginosa-Staphylococcus aureus.
Affiliation: BioSystems and Micromechanics IRG, Singapore-MIT Alliance for Research and Technology, National University of Singapore, Singapore.Show MeSH
Related in: MedlinePlus
Mentions: Particles were incorporated from the medium into the three biofilm-forming strains (Alg+ Pel+ Psl+, Alg+ Pel− Psl+, and Alg+ Pel+ Psl−), with increased uptake of the larger particles relative to the smaller particles. Particles were counted in 4- and 5-day biofilms, and the ratio of 1.0- to 0.5- and 0.2-µm particles was used as a measure of size selectivity in the three biofilm-forming strains (Fig. 2A). The Alg+ Pel+ Psl+ biofilm had 1.0- to 0.5- and 0.2-µm particle ratios of 2.02 ± 0.41 and 4.13 ± 1.24, respectively, while Alg+ Pel− Psl+ biofilm displayed ratios of 1.85 ± 0.55 and 4.81 ± 1.12, respectively. The Alg+ Pel+ Psl− biofilm, which was significantly impaired in biofilm development, had lower 1.0- to 0.5- and 0.2-µm particle ratios of 1.52 ± 0.31 and 2.44 ± 0.73, respectively. It was observed that the preference for 1.0-µm particles over the smaller particles was predominant in the microcolonies (Fig. 3). Hence strains that expressed the Psl polysaccharide and that formed more differentiated biofilms gave higher ratios of 1.0- to 0.5- and 0.2-µm particles.
Affiliation: BioSystems and Micromechanics IRG, Singapore-MIT Alliance for Research and Technology, National University of Singapore, Singapore.