Effect of arsenite on swimming motility delays surface colonization in Herminiimonas arsenicoxydans.
Herminiimonas arsenicoxydans is a Gram-negative bacterium able to detoxify arsenic-contaminated environments by oxidizing arsenite [As(III)] to arsenate [As(V)] and by scavenging arsenic ions in an extracellular matrix. Its motility and colonization behaviour have been previously suggested to be influenced by arsenite. Using time-course confocal laser scanning microscopy, we investigated its biofilm development in the absence and presence of arsenite. Arsenite was shown to delay biofilm initiation in the wild-type strain; this was partly explained by its toxicity, which caused an increased growth lag time. However, this delayed adhesion step in the presence of arsenite was not observed in either a swimming motility defective fliL mutant or an arsenite oxidase defective aoxB mutant; both strains displayed the wild-type surface properties and growth capacities. We propose that during the biofilm formation process arsenite acts on swimming motility as a result of the arsenite oxidase activity, preventing the switch between planktonic and sessile lifestyles. Our study therefore highlights the existence, under arsenite exposure, of a competition between swimming motility, resulting from arsenite oxidation, and biofilm initiation.
Marchal
M
M
Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS & Université de Strasbourg, Strasbourg, France.
Briandet
R
R
INRA, UMR1319 MICALIS, Massy, France.
Koechler
S
S
Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS & Université de Strasbourg, Strasbourg, France.
Kammerer
B
B
Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS & Université de Strasbourg, Strasbourg, France.
Bertin
P N
PN
Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS & Université de Strasbourg, Strasbourg, France.
D018053:Arsenites / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D018613:Microscopy, Confocal; D042802:Oxalobacteraceae / Q000187:drug effects / Q000502:physiology*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism
D018053:Arsenites; D010088:Oxidoreductases; C078179:arsenite oxidase; C015001:arsenite