Table 1.
Non-Saccharomyces isolates investigated in this study, as well as two S. cerevisiae controls.
Fig 1.
Pure culture flocculation (percentage) of the 18 non-Saccharomyces yeast isolates selected for this study based on their potential positive contribution to wine fermentation.
Values are the average of six repeats ± standard deviation.
Fig 2.
Co-flocculation (percentage) of the 18 non-Saccharomyces yeast isolates in combination with VIN13 (1:1 ratio of cells).
Increases and decreases in flocculation percentages for the combined cultures are calculated relative to the ‘theoretical average’ flocculation based on the combined and weighted average of the corresponding pure culture flocculation percentage. Total cfu/ml were identical for pure cultures and mixed cultures (in a 1:1 ratio). Values are the average of six repeats ± standard deviation.
Fig 3.
Microscopy image showing aggregation of S. cerevisiae (circular shaped cells) and H. uvarum (elongated cells) in mixed species flocs.
Frames A (S. cerevisiae) and B (H. uvarum) show pure cultures of these species while frames C and D show co-aggregates of these two species.
Table 2.
Overexpression and deletion S. cerevisiae mutant strains.
Fig 4.
Flocculation percentage of pure culture controls of the S. cerevisiae mutant strains and six non-Saccharomyces isolates (frame A).
Co-flocculation of mutant strains in combination with two H. opuntiae isolates (frame B), two C. flavescens (frame C) and one each of H. uvarum and M. fructicola are shown (frame D). Values are the average of six repeats ± standard deviation.
Fig 5.
Percentage of S. cerevisiae and H. opuntiae Y1055 cells in upper non-flocculent and lower flocculent fractions, present as either, single cells, mixed species flocs, or pure species flocs.
H. opuntiae in combination with FY23 is shown in frame A (upper layer) and B (lower), with FY23-FLO1 in frame C (upper) and D (lower), with FY23-FLO5 in frame E (upper) and F (lower) and in combination with FY23-FLO11 in frame G (upper) and H (lower).
Fig 6.
Fold change increase/decrease (based on fluorescent peak area differences) for each species between non-flocculent (top) and flocculent (bottom) fractions of assays conducted with a 6 species non-Saccharomyces yeast consortium in combination with the three FLO gene overexpressing S. cerevisiae mutant strains, as well as control FY23.
The S. cerevisiae data represent the different strains used in each of the four treatments, i.e. FY32 in the case of the FY32 strain in combination with the consortium, etc. Values are the average of three biological repeats.