Factors which Affect Velum Formation by Flor Yeasts Isolated from Sherry Wine

FLO11-Based Model for Air-Liquid Interfacial Biofilm Formation bySaccharomyces cerevisiae

“…4A), based in part on a mechanism proposed by Martínez et al (24). Increased FLO11 expression at the diauxic shift significantly increases cell surface hydrophobicity, which in turn leads to formation of multicellular aggregates.…”

“…With respect to flocculation, addition of mannose and other monosaccharides and proteolytic treatment have all been observed to be disruptive (13,32). Martínez et al (24) found that proteolytic treatment of a yeast biofilm on the surface of sherry had a similarly disruptive effect. It has been suggested that a reduction in the amount of phosphodiester-linked ␤-1,2-oligomannosyl branches of cell surface mannoproteins, rather than a reduction in total glycosylation, is sufficient to decrease the hydrophobicity of Candida albicans (26).…”

“…In contrast to other microbial biofilms, those formed by flor strains appear to consist of a layer of buoyant cells without a suspending extracellular polysaccharide or protein matrix, as no evidence for such extracellular material has been reported. Biofilm cells have been found to have an elevated and/or altered lipid content and an increased surface hydrophobicity (7,9,15,16,24). Recently, Zara et al (35) found that the small heat shock protein Hsp12 is required for biofilm formation in a Sardinian flor strain.…”

Ethanol-Independent Biofilm Formation by a Flor Wine Yeast Strain ofSaccharomyces cerevisiae

“…In general, nonbuoyant cells cease growth at the end of completed wine fermentations not for lack of carbon but for lack of oxygen. Biofilm cells have been found to have an elevated and/or altered lipid content and increased surface hydrophobicity (3,5,8,9,11). While both Hsp12, a small heat shock protein (13), and Muc1 (also known as Flo11), a hydrophobic cell wall mannoprotein (4, 6), have been shown to be required for the flor biofilm (10,12,14), other genetic or environmental requirements, other than an absence of glucose and the presence of ethanol and oxygen, have not been demonstrated.…”

Using Odorant Series as an Analytical Tool for the Study of the Biological Ageing of Sherry Wines

“…More than 95% of these yeasts are identified as Saccharomyces cerevisiae races (Martinez et al, 1997). These microorganisms grow spontaneously on the wine surface after the alcoholic fermentation of the must and develop an aerobic metabolism that endows the resulting product with typical sensory properties as regards the aroma (Cortes et al, 1998;Moyano et al, 2002;Moreno et al, 2005).…”