Biofilm Bacteria Use Stress Responses to Detect and Respond to Competitors.

Bacteria use complex regulatory networks to cope with stress, but the function of these networks in natural habitats is poorly understood. The competition sensing hypothesis states that bacterial stress response systems can serve to detect ecological competition, but studying regulatory responses in diverse communities is challenging. Here, we solve this problem by using differential fluorescence induction to screen the Salmonella Typhimurium genome for loci that respond, at the single-cell level, to life in biofilms with competing strains of S.

FabR regulates Salmonella biofilm formation via its direct target FabB.

Background: Biofilm formation is an important survival strategy of Salmonella in all environments. By mutant screening, we showed a knock-out mutant of fabR, encoding a repressor of unsaturated fatty acid biosynthesis (UFA), to have impaired biofilm formation. In order to unravel how this regulator impinges on Salmonella biofilm formation, we aimed at elucidating the S.

Gene expression variability in clonal populations: Causes and consequences.

During the last decade it has been shown that among cell variation in gene expression plays an important role within clonal populations. Here, we provide an overview of the different mechanisms contributing to gene expression variability in clonal populations. These are ranging from inherent variations in the biochemical process of gene expression itself, such as intrinsic noise, extrinsic noise and bistability to individual responses to variations in the local micro-environment, a phenomenon called phenotypic plasticity.

Gene expression analysis of monospecies Salmonella typhimurium biofilms using differential fluorescence induction.

Bacterial biofilm formation is an important cause of environmental persistence of food-borne pathogens, such as Salmonella Typhimurium. As the ensemble of bacterial cells within a biofilm represents different physiological states, even for monospecies biofilms, gene expression patterns in these multicellular assemblages show a high degree of heterogeneity. This heterogeneity might mask differential gene expression that occurs only in subpopulations of the entire biofilm population when using methods that average expression output.