Novel wine-mediated FLO11 flocculation phenotype of commercial Saccharomyces cerevisiae wine yeast strains with modified FLO gene expression.
Depending on the genetic background of Saccharomyces strains, a wide range of phenotypic adhesion identities can be directly attributed to the FLO11-encoded glycoprotein, which includes asexual flocculation, invasive growth and pseudohyphal formation, flor formation and adhesion to biotic and abiotic surfaces. In a previous study, we reported that HSP30-mediated stationary-phase expression of the native chromosomal FLO11 ORF in two nonflocculent commercial Saccharomyces cerevisiae wine yeast strains, BM45 or VIN13 did not generate a flocculent phenotype under either standard laboratory media or synthetic MS300 must fermentation conditions. In the present study, the BM45- and VIN13-derived HSP30p-FLO11 wine yeast transformants were observed to be exclusively and strongly flocculent under authentic red wine-making conditions, thus suggesting that this specific fermentation environment specifically contributes to the development of a flocculent phenotype, which is insensitive to either glucose or mannose. Furthermore, irrespective of the strain involved this phenotype displayed both Ca(2+)-dependent and Ca(2+)-independent flocculation characteristics. A distinct advantage of this unique FLO11-based phenotype was highlighted in its ability to dramatically promote faster lees settling rates. Moreover, wines produced by BM45-F11H and VIN13-F11H transformants were significantly less turbid than those produced by their wild-type parental strains.
Department of Biochemistry, University of KwaZulu-Natal, Durban, South Africa.
Patrick
P
Govender
Sven
S
Kroppenstedt
Florian F
FF
Bauer
D015966:Gene Expression Regulation, Fungal; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D009391:Nephelometry and Turbidimetry; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014920:Wine / Q000382:microbiology*
C110690:FLO11 protein, S cerevisiae; D008562:Membrane Glycoproteins; D029701:Saccharomyces cerevisiae Proteins