title: Identification of a novel matrix protein that promotes biofilm maturation in Vibrio fischeri.
abstract: Bacteria form communities, termed biofilms, in which cells adhere to each other within a matrix, typically comprised of polysaccharides, proteins, and extracellular DNA. Biofilm formation by the marine bacterium Vibrio fischeri requires the Syp polysaccharide, but the involvement of matrix proteins is as yet unknown. Here we identified three genes, termed bmpA, -B, and -C (biofilm maturation protein), with overlapping functions in biofilm maturation. A triple bmpABC mutant, but not single or double mutants, was defective in producing wrinkled colonies, a form of biofilm. Surprisingly, the triple mutant was competent to form pellicles, another biofilm phenotype, but they generally lacked a three-dimensional architecture. Transmission electron microscopy revealed that the extracellular matrix of the bmp mutant contained electron-dense, thread-like structures that were also present in the wild type but lacking in syp mutant strains. We hypothesized that the bmp mutant produces the Syp polysaccharide but fails to produce/export a distinct matrix component. Indeed, a mixture of the bmp and syp mutants produced a wrinkled colony. Finally, BmpA could be detected in cell-free supernatants from disrupted pellicles. Thus, this work identifies a new matrix protein necessary for biofilm maturation by V. fischeri and, based on the conservation of bmp, potentially other microbes.
authors.affiliation: Department of Microbiology and Immunology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA.
authors.forename: Valerie A
authors.initials: VA
authors.lastname: Ray
authors.affiliation: Department of Microbiology and Immunology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Driks
authors.affiliation: Department of Microbiology and Immunology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA kvisick@luc.edu.
authors.forename: Karen L
authors.identifier: http://orcid.org/0000-0002-2400-2591
authors.initials: KL
authors.lastname: Visick
mesh_terms: D048908:Aliivibrio fischeri / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D017353:Gene Deletion; D046911:Macromolecular Substances / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D055503:Protein Multimerization
chemical_list: D001426:Bacterial Proteins; D046911:Macromolecular Substances