title: Planktonic cell yield is linked to biofilm development.
abstract: We report on the ability of surface-associated microbes to produce and release single planktonic cells to the bulk liquid as early as 6 h after attachment, with pure culture and mixed-species biofilms yielding up to approximately 1 x 10(6) cells/cm(2) of attachment area per hour to the effluent after 24 h. Planktonic cell production typically increased as the biofilm developed and levelled off after the biofilm reached steady-state dimensions. Microscopic observations of continuous-flow cultured biofilms revealed independent cell movement within the biofilm microenvironment compared with flow-dependent movement of mostly single cells in the bulk-liquid phase. These results indicate that the prevailing concept of detachment occurring only after the biofilm has matured is incomplete. Instead, we show that biofilms yield cells to the environment soon after initial surface contact; the extent of this yield is dependent on biofilm development, which in turn is influenced by environmental parameters such as bulk-liquid flow rates and nutrient availability. The observation that biofilms yield significant numbers of cells throughout development should lead to a greater understanding of pathogen dissemination, biofouling of products or facilities, and the role that biofilms play in microbial proliferation in the environment.
authors: Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3, Canada.
authors: Elanna
authors: E
authors: Bester
authors: Elizabeth A
authors: EA
authors: Edwards
authors: Gideon M
authors: GM
authors: Wolfaardt
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development*; D019149:Bioreactors / Q000382:microbiology; D015169:Colony Count, Microbial; D003470:Culture Media; D004783:Environmental Microbiology; D005434:Flow Cytometry; D049452:Green Fluorescent Proteins / Q000235:genetics; D010933:Plankton / Q000166:cytology / Q000254:growth & development*; D011550:Pseudomonas aeruginosa / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000502:physiology*; D011994:Recombinant Proteins / Q000235:genetics
chemical_list: D003470:Culture Media; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins