title: Air-liquid biofilm formation is dependent on ammonium depletion in a Saccharomyces cerevisiae flor strain.
abstract: Air-liquid biofilm formation appears to be an adaptive mechanism that promotes foraging of Saccharomyces cerevisiae flor strains in response to nutrient starvation. The FLO11 gene plays a central role in this phenotype as its expression allows yeast cells to rise to the liquid surface. Here, we investigated the role of ammonium depletion in air-liquid biofilm formation and FLO11 expression in a S. cerevisiae flor strain. The data obtained show that increasing ammonium concentrations from 0 to 450 m m reduce air-liquid biofilm in terms of biomass and velum formation and correlate with a reduction of FLO11 expression. Rapamycin inhibition of the TOR pathway and deletion of RAS2 gene significantly reduced biofilm formation and FLO11 expression. Taken together, these data suggest that ammonium depletion is a key factor in the induction of air-liquid biofilm formation and FLO11 expression in S. cerevisiae flor strains.
authors.affiliation: Dipartimento di Scienze Ambientali Agrarie e Biotecnologie Agroalimentari, Sezione di Microbiologia Generale ed Applicata, Università degli Studi di Sassari, 07100, Sassari, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Zara
authors.forename: Marilena
authors.initials: M
authors.lastname: Budroni
authors.forename: Ilaria
authors.initials: I
authors.lastname: Mannazzu
authors.forename: Severino
authors.initials: S
authors.lastname: Zara
mesh_terms: D018441:Biofilms; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D020123:Sirolimus / Q000494:pharmacology; D018631:ras Proteins / Q000235:genetics
chemical_list: C110690:FLO11 protein, S cerevisiae; D008562:Membrane Glycoproteins; D000644:Quaternary Ammonium Compounds; D029701:Saccharomyces cerevisiae Proteins; D017346:Protein Serine-Threonine Kinases; C500749:target of rapamycin protein, S cerevisiae; C489015:RAS2 protein, S cerevisiae; D018631:ras Proteins; D020123:Sirolimus