title: Dispersal of biofilms by secreted, matrix degrading, bacterial DNase.
abstract: Microbial biofilms are composed of a hydrated matrix of biopolymers including polypeptides, polysaccharides and nucleic acids and act as a protective barrier and microenvironment for the inhabiting microbes. While studying marine biofilms, we observed that supernatant produced by a marine isolate of Bacillus licheniformis was capable of dispersing bacterial biofilms. We investigated the source of this activity and identified the active compound as an extracellular DNase (NucB). We have shown that this enzyme rapidly breaks up the biofilms of both Gram-positive and Gram-negative bacteria. We demonstrate that bacteria can use secreted nucleases as an elegant strategy to disperse established biofilms and to prevent de novo formation of biofilms of competitors. DNA therefore plays an important dynamic role as a reversible structural adhesin within the biofilm.
authors.affiliation: Dove Marine Laboratory, School of Marine Science and Technology, Newcastle University, North Shields, United Kingdom.
authors.forename: Reindert
authors.initials: R
authors.lastname: Nijland
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hall
authors.forename: J Grant
authors.initials: JG
authors.lastname: Burgess
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D001407:Bacillus / Q000201:enzymology*; D001419:Bacteria / Q000201:enzymology; D001426:Bacterial Proteins; D001483:Base Sequence; D018441:Biofilms; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D003851:Deoxyribonucleases / Q000235:genetics*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005838:Genotype; D008969:Molecular Sequence Data; D010957:Plasmids / Q000378:metabolism; D011108:Polymers / Q000737:chemistry; D012260:Ribonucleases / Q000378:metabolism
chemical_list: D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D017931:DNA Primers; D011108:Polymers; D003851:Deoxyribonucleases; D012260:Ribonucleases; C025580:endodeoxyribonuclease XBAI; D015252:Deoxyribonucleases, Type II Site-Specific; C019760:Bacillus amyloliquefaciens ribonuclease