Gliding movements of individual isolated Myxococcus xanthus cells depend on the genes of the A-motility system (agl and cgl genes). Mutants carrying defects in those genes are unable to translocate as isolated cells on solid surfaces. The motility defect of cgl mutants can be transiently restored to wild type by extracellular complementation upon mixing mutant cells with wild-type or other moti...

Serratia marcescens swarming behavior is characterized by continuous populational surface migration on swarming agar at 30°C, but not at 37°C. The underlying mechanism how S. marcescens population starts to initiate swarming and the temperature-dependent regulation of swarming behaviour are currently uncharacterized. We identify in S. marcescens a genetic locus that, when mutated, results in a ...

We present a cell-based model to simulate the swarming behavior of various mutants of myxobacteria. Computational complexity is often known to be one of the biggest obstacles in simulating such biological system as there are too many interacting individuals involved in the system. We derive the scaling law for our model, which together with the concept of superindividuals, enable us to perform ...

The bulk of bacterial protein secretion occurs through the conserved SecY translocation channel that is powered by SecA-dependent ATP hydrolysis. Many Gram-positive bacteria, including the human pathogen Listeria monocytogenes, possess an additional nonessential specialized ATPase, SecA2. SecA2-dependent secretion is required for normal cell morphology and virulence in L. monocytogenes; however...

Swarming, a flagellar-driven multicellular form of motility, is associated with bacterial virulence and increased antibiotic resistance. In this work we demonstrate that activation of the SOS response reversibly inhibits swarming motility by preventing the assembly of chemoreceptor-signaling polar arrays. We also show that an increase in the concentration of the RecA protein, generated by SOS s...

Pseudomonas aeruginosa produces extracellular glycolipids composed of L-rhamnose and 3-hydroxyalkanoic acid called rhamnolipids. Although these compounds are usually regarded as biosurfactants or haemolysins, their exact physiological function is not well understood. Rhamnolipids are synthesized by a rhamnosyltransferase, encoded by the rhlAB operon, which catalyses the transfer of TDP-L-rhamno...

The intracellular signaling molecule, cyclic-di-GMP (c-di-GMP), has been shown to influence bacterial behaviors, including motility and biofilm formation. We report the identification and characterization of PA4367, a gene involved in regulating surface-associated behaviors in Pseudomonas aeruginosa. The PA4367 gene encodes a protein with an EAL domain, associated with c-di-GMP phosphodiesteras...

Circadian rhythms are fundamental properties of most eukaryotes, but evidence of biological clocks that drive these rhythms in prokaryotes has been restricted to Cyanobacteria. In vertebrates, the gastrointestinal system expresses circadian patterns of gene expression, motility and secretion in vivo and in vitro, and recent studies suggest that the enteric microbiome is regulated by the host's ...

Pseudomonas aeruginosa is a monoflagellated bacterium that can use its single polar flagellum to swim through liquids and move collectively over semisolid surfaces, a behavior called swarming. Previous studies have shown that experimental evolution in swarming colonies leads to the selection of hyperswarming bacteria with multiple flagella. Here we show that the advantage of such hyperswarmer m...

Two-component systems are capable of profoundly affecting genetic regulation in bacteria by detecting environmental stimuli, allowing them to quickly adapt. In Pseudomonas aeruginosa, the small RNAs (sRNAs) RsmY and RsmZ are under the control of the GacS/A system. They have been described as ones of the major key players in the control of planktonic and surface-associated behaviors. Genetic reg...