title: Effect of gacS and gacA mutations on colony architecture, surface motility, biofilm formation and chemical toxicity in Pseudomonas sp. KL28.
abstract: GacS and GacA proteins form a two component signal transduction system in bacteria. Here, Tn5 transposon gacS and gacA (Gac) mutants of Pseudomonas sp. KL28, an alkylphenol degrader, were isolated by selecting for smooth colonies of strain KL28. The mutants exhibited reduced ability to migrate on a solid surface. This surface motility does not require the action of flagella unlike the well-studied swarming motility of other Pseudomonas sp. The Gac mutants also showed reduced levels of biofilm and pellicle formation in liquid culture. In addition, compared to the wild type KL28 strain, these mutants were more resistant to high concentrations of m-cresol but were more sensitive to H2O2, which are characteristics that they share with an rpoS mutant. These results indicate that the Gac regulatory cascade in strain KL28 positively controls wrinkling morphology, biofilm formation, surface translocation and H2O2 resistance, which are important traits for its capacity to survive in particular niches.
authors.affiliation: Department of Microbiology, Changwon National University, Changwon, Republic of Korea.
authors.forename: Kyung Soon
authors.initials: KS
authors.lastname: Choi
authors.forename: Yaligara
authors.initials: Y
authors.lastname: Veeraragouda
authors.forename: Kyung Mi
authors.initials: KM
authors.lastname: Cho
authors.forename: Soo O
authors.initials: SO
authors.lastname: Lee
authors.forename: Geuk Rae
authors.initials: GR
authors.lastname: Jo
authors.forename: Kyungyun
authors.initials: K
authors.lastname: Cho
authors.forename: Kyoung
authors.initials: K
authors.lastname: Lee
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D003408:Cresols / Q000494:pharmacology; D004251:DNA Transposable Elements / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D046529:Microscopy, Electron, Transmission; D008954:Models, Biological; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D010641:Phenotype; D011549:Pseudomonas / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D017422:Sequence Analysis, DNA; D012808:Sigma Factor / Q000235:genetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D003408:Cresols; D004251:DNA Transposable Elements; C091100:GacA protein, Bacteria; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D049452:Green Fluorescent Proteins; C032538:4-cresol; D006861:Hydrogen Peroxide