Dataset Information

FLO11-based model for air-liquid interfacial biofilm formation by Saccharomyces cerevisiae.

ABSTRACT: Sardinian wine strains of Saccharomyces cerevisiae used to make sherry-like wines form a biofilm at the air-liquid interface at the end of ethanolic fermentation, when grape sugar is depleted and further growth becomes dependent on access to oxygen. Here, we show that FLO11, which encodes a hydrophobic cell wall glycoprotein, is required for the air-liquid interfacial biofilm and that biofilm cells have a buoyant density greater than the suspending medium. We propose a model for biofilm formation based on an increase in cell surface hydrophobicity occurring at the diauxic shift. This increase leads to formation of multicellular aggregates that effectively entrap carbon dioxide, providing buoyancy. A visible biofilm appears when a sufficient number of hydrophobic cell aggregates are carried to and grow on the liquid surface.

SUBMITTER: Zara S

PROVIDER: S-EPMC1151800 | biostudies-literature | 2005 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

FLO11-based model for air-liquid interfacial biofilm formation by Saccharomyces cerevisiae.

Zara Severino S Bakalinsky Alan T AT Zara Giacomo G Pirino Giorgia G Demontis Maria Antonietta MA Budroni Marilena M

Applied and environmental microbiology 20050601 6

Sardinian wine strains of Saccharomyces cerevisiae used to make sherry-like wines form a biofilm at the air-liquid interface at the end of ethanolic fermentation, when grape sugar is depleted and further growth becomes dependent on access to oxygen. Here, we show that FLO11, which encodes a hydrophobic cell wall glycoprotein, is required for the air-liquid interfacial biofilm and that biofilm cells have a buoyant density greater than the suspending medium. We propose a model for biofilm formatio ...[more]

PMID: 15932987

Similar Datasets

Project description:Goal was to identify yeast genes whose expression changed as a function of the shift from growth in bulk culture to growth in an air-liquid interfacial biofilm. Experiment Overall Design: Cells were grown 24 h at 30 C in YEPD to a density of about 500,000,000 cells/ml. At harvest, sugar was found to be depleted as measured by an enzymatic dip stick (Diastic, Bayer). Cells were pelleted and washed twice in sterile distilled water by centrifugation and then diluted 10-fold into 100 ml of Flor medium (YNB + 4% ethanol + leucine + histidine + uracil) in triplicate 250 ml beakers. Cultures were then grown statically in Flor medium at 27 C. Within a few hours following inoculation, the bulk liquid appeared to be clear, no biofilm was evident by visual observation, and a layer of settled cells was evident at the bottom of the beakers. After 48 h, a visible air-liquid interfacial biofilm covered the entire surface while the thickness of the layer of settled cells appeared unchanged. After 48 h, biofilm cells (floaters) were collected by aseptic aspiration. Once the biofilm cells were removed, cells at the bottom of the beaker (sinkers) were collected similarly. Cells from both populations were washed once in sterile distilled water by centrifugation prior to RNA isolation. Significant cell clumping was evident in both populations of cells by microscopic observation. While cell viability was estimated by plating on YEPD, the resultant cfu/ml values could not be directly correlated with cell counts in a hemacytometer because clumps of cells containing at least one viable cell presumably produced only a single colony. Further, counting individual cells accurately in the numerous clumps containing large numbers of cells was not possible. Nonetheless, when cells were counted (clumps were counted as single cells) and compared to cfu/ml for the same suspension, the cfu/ml values were about 2-fold higher than the corresponding values for cell counts using the hemacytometer for both biofilm and bottom layer cells.

Dataset Information

FLO11-based model for air-liquid interfacial biofilm formation by Saccharomyces cerevisiae.

Publications

FLO11-based model for air-liquid interfacial biofilm formation by Saccharomyces cerevisiae.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets