Table 1.
Collection of S. cerevisiae strains from diverse environments and geographical locations.
Figure 1.
Comparison of the fermentation profiles for 72 S. cerevisiae strains fromdiverse geographical locales and environments.
Fermentations were carried out in synthetic medium containing 240 g/L glucose, 200 mg/L nitrogen, pH 3.5. The fermentation profiles are presented as the CO2 production rate vs. the fermentation progress, which corresponded to the ratio of consumed glucose to initial glucose. The lines are colored according to the origin of the strains: vineyard (purple), soil (grey), sake (light grey), palm wine (pink), oak (brown), laboratory (yellow), fruit (red), wine commercial (dark green), Bertam-palm (blue), baker (black), beer (dark grey), cactus (light blue).
Figure 2.
Distribution frequency of the phenotypic variables in the total population (72 strains).
Closed circle: mean value; open circle: median value. Kinetics variables (CO2F, Vmax, V50, T50 and T75) were determined from the fermentation curves. Growth (cell number and dry weight) and metabolic variables (glycerol, acetate, succinate, two higher alcohols, two acetate esters and four ethyl esters) were measured when 75% of the sugars were consumed (180 g/L).
Figure 3.
Relationships between the phenotypic variables within the total population of strains.
Correlations were found between: the fermentative activity at mid-fermentation V50 and the time necessary to consume 50% or 75% of sugars, T50 (A) and T75 (B), respectively; the final CO2 release and the dry weight (C); and the production of isoamyl acetate and the productions of isoamyl alcohol (▪) and isobutyl acetate (○) (D).
Table 2.
Univariate analysis of the variance for the phenotypic variables.
Figure 4.
Abilities of the 72 strains from different environments to efficiently ferment a high concentration of sugar.
Strains were considered able to achieve fermentation of 240 g/L of sugar when their production of CO2 at the end of fermentation (A) was higher than 105 g/L. These strains were further discriminated by the fermentation time (B). Vineyard: purple symbols; soil: grey symbols; sake: green symbols; palm: pink symbols, oak: brown symbols; laboratory: yellow symbols; fruit: red symbols; wine commercial: dark green symbols; clinical: tan symbols, cactus: blue symbols; Bertam –palm wine: dark blue symbols; beer: beige symbols ; baker: black symbols.
Table 3.
Comparison of the phenotypic variables between strains isolated from the wine commercial and vineyard strain groups.
Figure 5.
Linear discriminant analysis (LDA) of the population based on five discriminating phenotypic traits.
A linear discriminant analysis was applied to the most discriminating variables: dry weight, T75, CO2F, acetate and ethyl butyrate measured for 53 strains representing 10 different groups. Clinical isolates were not included, due to the large phenotypic variability observed among the strains in this group. Beer and cactus groups, with only two strains each, were removed for this analysis. Groups of origin include vineyard (purple), soil (grey), sake (green), palm wine (pink), oak (brown), laboratory (yellow), fruit (red), wine commercial (dark green), Bertam-palm (dark blue), baker (black).