Dipartimento di Scienze Ambientali Agrarie e Biotecnologie Agroalimentari, Sezione di Microbiologia Generale ed Applicata, Università degli Studi di Sassari, 07100, Sassari, Italy.
Yeast. 2011 Dec;28(12):809-14. doi: 10.1002/yea.1907. Epub 2011 Oct 4.
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.
空气-液体生物膜的形成似乎是一种适应性机制，促进了酿酒酵母花型菌株在营养饥饿时的觅食。FLO11 基因在这种表型中起着核心作用，因为它的表达使酵母细胞能够上升到液体表面。在这里，我们研究了在酿酒酵母花型菌株中，铵耗尽在空气-液体生物膜形成和 FLO11 表达中的作用。获得的数据表明，从 0 到 450 mM 增加铵浓度会降低生物膜的生物量和 velum 形成，这与 FLO11 表达的减少相关。雷帕霉素抑制 TOR 途径和 ras2 基因缺失显著降低了生物膜的形成和 FLO11 的表达。综上所述，这些数据表明，铵耗尽是诱导酿酒酵母花型菌株空气-液体生物膜形成和 FLO11 表达的关键因素。
