Project description:We report mRNA expression data from Pseudomonas fluorescens SBW25 wild type and two evolved strains (Beaumont et al., 2009). The evolution of one of these strains saw the emergence of colony switching; 1B4 switches rapidly between two different colony phenotypes. These two phenotypes were found to be genetically identical. Thus, in order to gain insight into epigenetic mechanisms of switching, we were interested in identifiying gene expression differences between ancestors and the 1B4 colony phenotypes.
Project description:35 P. aeruginosa clinical strains were cultivated under standard conditions, characterized in terms of virulence and biofilm phenotype, and their metabolomes were investigated by untargeted liquid chromatography-mass spectrometry.
Project description:To assess the role of two redox-sensitive transcriptional regulators, RoxSR and ANR, in Pseudomonas aeruginosa under aerobic conditions, microarray analysis was performed. Transcriptome profiles of roxSR mutant and anr mutant aerobically grown in LB medium were determined by Affymetrix GeneChip at both the exponential phase and early stationary phase and compared to that of the wild type strain. Experiment Overall Design: Pseudomonas aeruginosa wild type (PAO1ut), roxSR mutant (ROX1), and anr mutant (PAO6261) strains were cultivated aerobically in LB in Erlenmeyer flasks, and total RNAs were extracted at both the exponential phase (OD600 = 0.3) and early stationary phase (OD600 = 1.4). The experiment was performed in duplicate independent cultures.
Project description:The transcriptome of two different Pseudomonas aeruginosa mutant strains were compared to the Pseudomonas aeruginosa wild type strain in the stationary growth phase
Project description:Comparative genomics has greatly facilitated the identification of shared as well as unique features among individual cells or tissues, and thus offers the potential to find disease markers. While proteomics is recognized for its potential to generate quantitative maps of protein expression, comparative proteomics in bacteria has been largely restricted to the comparison of single cell lines or mutant strains. In this study, we used a data independent acquisition (DIA) technique, which enables global protein quantification of large sample cohorts, to record the proteome profiles of overall 27 whole genome sequenced and transcriptionally profiled clinical isolates of the opportunistic pathogen Pseudomonas aeruginosa. Analysis of the proteome profiles across the 27 clinical isolates grown under planktonic and biofilm growth conditions led to the identification of a core biofilm-associated protein profile. Furthermore, we found that protein-to-mRNA ratios between different P. aeruginosa strains are well correlated, indicating conserved patterns of post-transcriptional regulation. Uncovering core regulatory pathways, which drive biofilm formation and associated antibiotic tolerance in bacterial pathogens, promise to give clues to interactions between bacterial species and their environment and could provide useful targets for new clinical interventions to combat biofilm-associated infections.
Project description:KaiC is the central cog of the circadian clock in Cyanobacteria. Close homologs of this protein are widespread among bacteria not known to have a circadian physiology. The function, interaction network, and mechanism of action of these KaiC homologs are still largely unknown. Here, we focus on KaiC homologs found in environmental Pseudomonas species. We characterize experimentally the only KaiC homolog present in Pseudomonas putida KT2440 and Pseudomonas protegens CHA0. Through phenotypic assays and transcriptomics, we show that KaiC is involved in osmotic and oxidative stress resistance in P. putida and in biofilm production in both P. putida and P. protegens.