title: TOL plasmid carriage enhances biofilm formation and increases extracellular DNA content in Pseudomonas putida KT2440.
abstract: Adherent growth of Pseudomonas putida KT2440 with and without the TOL plasmid (pWWO) at the solid-liquid and air-liquid interface was examined. We compared biofilm formation on glass in flow cells, and assayed pellicle (air-liquid interface biofilm) formation in stagnant liquid cultures by confocal laser scanning microscopy. The TOL-carrying strains formed pellicles and thick biofilms, whereas the same strains without the plasmid displayed little adherent growth. Microscopy using fluorescent nucleic acid-specific stains revealed differences in the production of extracellular polymeric substances: TOL carriage leads to more extracellular DNA (eDNA) in pellicles and biofilms. Pellicles were dissolved by DNase I treatment. Enhanced cell lysis due to plasmid carriage was ruled out as the mechanism for eDNA release. We report, for the first time, that carriage of a conjugative plasmid leads to increased biofilm formation by production of eDNA.
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Kongens Lyngby, Denmark.
authors.forename: Paul W
authors.initials: PW
authors.lastname: D'Alvise
authors.forename: Ole R
authors.initials: OR
authors.lastname: Sjøholm
authors.forename: Tatiana
authors.initials: T
authors.lastname: Yankelevich
authors.forename: Yujie
authors.initials: Y
authors.lastname: Jin
authors.forename: Stefan
authors.initials: S
authors.lastname: Wuertz
authors.forename: Barth F
authors.initials: BF
authors.lastname: Smets
mesh_terms: D018441:Biofilms; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D005110:Extracellular Space / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics* / Q000378:metabolism; D016958:Pseudomonas putida / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
chemical_list: D004269:DNA, Bacterial