Dynamic Response of Pseudomonas putida S12 to Sudden Addition of Toluene and the Potential Role of the Solvent Tolerance Gene trgI

• Published in: PloS one Vol. 10; no. 7; p. e0132416
• Main Authors: Volkers, Rita J M, Snoek, L Basten, Ruijssenaars, Harald J, de Winde, Johannes H
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 16.07.2015; Public Library of Science (PLoS)
• Subjects: Adaptation; Adaptation, Physiological - genetics; aeruginosa; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Clonal deletion; Cytochrome; Cytochrome oxidase; Cytochrome-c oxidase; Dynamic response; E coli; Efflux; Electron Transport Complex IV - genetics; Electron Transport Complex IV - metabolism; Escherichia coli; fatty-acid; Fermentation; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Gene Knockout Techniques; Genes; Genome, Bacterial; Genomes; Genomics; Glyoxylates - metabolism; Laboratories; metabolism; Microorganisms; molecular characterization; Molecular Sequence Annotation; Organic solvents; Oxidation-Reduction; Oxygen; Plant sciences; Polyamines; Proteins; Pseudomonas aeruginosa; Pseudomonas putida; Pseudomonas putida - drug effects; Pseudomonas putida - genetics; Pseudomonas putida - metabolism; Solvents; Solvents - pharmacology; stress; Time Factors; Toluene; Toluene - pharmacology; Transcription; Transcription, Genetic; transcriptional regulator
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0132416

Pseudomonas putida S12 is exceptionally tolerant to various organic solvents. To obtain further insight into this bacterium's primary defence mechanisms towards these potentially harmful substances, we studied its genome wide transcriptional response to sudden addition of toluene. Global gene expression profiles were monitored for 30 minutes after toluene addition. During toluene exposure, high oxygen-affinity cytochrome c oxidase is specifically expressed to provide for an adequate proton gradient supporting solvent efflux mechanisms. Concomitantly, the glyoxylate bypass route was up-regulated, to repair an apparent toluene stress-induced redox imbalance. A knock-out mutant of trgI, a recently identified toluene-repressed gene, was investigated in order to identify TrgI function. Remarkably, upon addition of toluene the number of differentially expressed genes initially was much lower in the trgI-mutant than in the wild-type strain. This suggested that after deletion of trgI cells were better prepared for sudden organic solvent stress. Before, as well as after, addition of toluene many genes of highly diverse functions were differentially expressed in trgI-mutant cells as compared to wild-type cells. This led to the hypothesis that TrgI may not only be involved in the modulation of solvent-elicited responses but in addition may affect basal expression levels of large groups of genes.