In Pantoea stewartii subsp. stewartii, two regulatory proteins are key to the process of cell-cell communication known as quorum sensing: the LuxI and LuxR homologues EsaI and EsaR. Most LuxR homologues function as activators of transcription in the presence of their cognate acylated homoserine lactone (AHL) signal. However, EsaR was initially found to function as a repressor in the absence of ...

Quorum sensing is a mechanism for regulating proteobacterial gene expression in response to changes in cell population. In proteobacteria, N-acyl homoserine lactone (AHL) appears to be the most widely used signalling molecules in mediating, among others, the production of extracellular virulence factors for survival. In this work, the genome of B. cepacia strain GG4, a plasmid-free strain capab...

BACKGROUND Members of the genus Novosphingobium have been isolated from a variety of environmental niches. Although genomics analyses have suggested the presence of genes associated with quorum sensing signal production e.g., the N-acyl-homoserine lactone (AHL) synthase (luxI) homologs in various Novosphingobium species, to date, no luxI homologs have been experimentally validated. METHODS In...

Australian Hardboards (AHL) own and operate a wet process hardboard manufacturing plant in Queensland, Australia, that generates a significant quantity of process water effluent during the production of Masonite. AHL management recognised that there were significant opportunities to reduce water and energy usage in the process without adversely affecting product quality. Sinclair Knight Merz (S...

Pseudomonas chlororaphis subsp. aurantiaca StFRB508 regulates phenazine production through N-acyl-l-homoserine lactone (AHL)-mediated quorum sensing. Two sets of AHL-synthase and AHL-receptor genes, phzI/phzR and aurI/aurR, have been identified from the incomplete draft genome of StFRB508. In the present study, the complete genome of StFRB508, comprising a single chromosome of 6,997,933 bp, was...

Quorum sensing, a process of bacterial cell-cell communication, relies on production, detection, and response to autoinducer signaling molecules. LuxN, a nine-transmembrane domain protein from Vibrio harveyi, is the founding example of membrane-bound receptors for acyl-homoserine lactone (AHL) autoinducers. We used mutagenesis and suppressor analyses to identify the AHL-binding domain of LuxN a...

The consequences of the boundary conditions (signal reflecting vs. signal adsorbing) on bacterial intercellular communication were addressed by a combined physics and microbiology approach. A predictive biophysical model was devised that considered system size, diffusion from given points, signal molecule decay and boundary properties. The theoretical predictions were tested with two experiment...

infection, even when challenged with comparatively low numbers of bacteria. The result is a triumph for the approach of mining bacterial metabolic diversity for applied uses. In this case, Dong et al. capitalized on the discovery that many bacteria can degrade, and so inactivate, AHLs. Earlier, the same group 5 had isolated hundreds of bacterial species from soil and screened them for the abili...