title: Biofilm formation and interactions of bacterial strains found in wastewater treatment systems.
abstract: Biofilm formation and adherence properties of 13 bacterial strains commonly found in wastewater treatment systems were studied in pure and mixed cultures using a crystal violet microtiter plate assay. Four different culture media were used, wastewater, acetate medium, glucose medium and diluted nutrient broth. The medium composition strongly affected biofilm formation. All strains were able to form pure culture biofilms within 24 h in at least one of the tested culture media and three strains were able to form biofilm in all four culture media, namely Acinetobacter calcoaceticus ATCC 23055, Comamonas denitrificans 123 and Pseudomonas aeruginosa MBL 0199. The adherence properties assessed were initial adherence, cell surface hydrophobicity, and production of amyloid fibers and extracellular polymeric substances. The growth of dual-strain biofilms showed that five organisms formed biofilm with all 13 strains while seven formed no or only weak biofilm when cocultured. In dual-strain cultures, strains with different properties were able to complement each other, giving synergistic effects. Strongest biofilm formation was observed when a mixture of all 13 bacteria were grown together. These results on attachment and biofilm formation can serve as a tool for the design of tailored systems for the degradation of municipal and industrial wastewater.
authors.affiliation: Department of Environmental Microbiology, Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden.
authors.forename: Sofia
authors.initials: S
authors.lastname: Andersson
authors.forename: Gunaratna
authors.initials: G
authors.lastname: Kuttuva Rajarao
authors.forename: Carl Johan
authors.initials: CJ
authors.lastname: Land
authors.forename: Gunnel
authors.initials: G
authors.lastname: Dalhammar
mesh_terms: D016954:Acinetobacter calcoaceticus / Q000502:physiology*; D000682:Amyloid / Q000502:physiology; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D020585:Comamonas / Q000502:physiology*; D003470:Culture Media; D057927:Hydrophobic and Hydrophilic Interactions; D017404:In Situ Hybridization, Fluorescence; D018613:Microscopy, Confocal; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D014865:Waste Disposal, Fluid; D014871:Water Microbiology; D018508:Water Purification
chemical_list: D000682:Amyloid; D003470:Culture Media