Temperature and pyoverdine-mediated iron acquisition control surface motility of Pseudomonas putida.
Pseudomonas putida KT2440 is unable to swarm at its common temperature of growth in the laboratory (30 degrees C) but exhibits surface motility similar to swarming patterns in other Pseudomonas between 18 degrees C and 28 degrees C. These motile cells show differentiation, consisting on elongation and the presence of surface appendages. Analysis of a collection of mutants to define the molecular determinants of this type of surface movement in KT2440 shows that while type IV pili and lipopolysaccharide O-antigen are requisites flagella are not. Although surface motility of flagellar mutants was macroscopically undistinguishable from that of the wild type, microscopy analysis revealed that these mutants move using a distinct mechanism to that of the wild-type strain. Mutants either in the siderophore pyoverdine (ppsD) or in the FpvA siderophore receptor were also unable to spread on surfaces. Motility in the ppsD strain was totally restored with pyoverdine and partially with the wild-type ppsD allele. Phenotype of the fpvA strain was not complemented by this siderophore. We discuss that iron influences surface motility and that it can be an environmental cue for swarming-like movement in P. putida. This study constitutes the first report assigning an important role to pyoverdine iron acquisition in en masse bacterial surface movement.
Matilla
Miguel A
MA
Department of Environmental Protection, Estación Experimental del Zaidin, CSIC, Profesor Albareda, 1 Granada 18008, Spain.
Ramos
Juan L
JL
Duque
Estrella
E
de Dios Alché
Juan
J
Espinosa-Urgel
Manuel
M
Ramos-González
María Isabel
MI
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D005407:Flagella / Q000502:physiology; D005798:Genes, Bacterial / Q000235:genetics; D005816:Genetic Complementation Test; D007501:Iron / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D009068:Movement / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D009841:Oligonucleotides; D009842:Oligopeptides / Q000235:genetics / Q000378:metabolism*; D016958:Pseudomonas putida / Q000235:genetics / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D017262:Siderophores / Q000378:metabolism*; D013696:Temperature
D001425:Bacterial Outer Membrane Proteins; D009841:Oligonucleotides; D009842:Oligopeptides; D011956:Receptors, Cell Surface; D017262:Siderophores; C035902:siderophore receptors; C042453:pyoverdin; D007501:Iron