# Evaluation of Probiotic _Saccharomyces boulardii_ Yeast as a Distillery Strain
## 3 Results and Discussion
### HPLC Analysis of Fermented Media
#### 3.2.1 Results of HPLC Analysis of Molasses Worts After Fermentation
Statistical analysis of the fructose concentration shows a significant difference between the results obtained for SB and ER strains, with a disproportion of 2.42 g/L to the disadvantage of SB yeast. The poorest sugar assimilation by _S. boulardii_ yeast sugars should be translated into reduced ethanol production. Despite this, no statistically significant differences in ethanol content were detected in the samples. The highest ethanol concentration was recorded in the sample fermented with TD yeast (31.81 g/L). Analysis of organic acids reveals that on the word in question, SB yeast produced the most acid: citric acid (0.33 g/L), succinic acid (0.3 g/L), and acetic acid (1.07 g/L). Statistical differences between _S. boulardii_ and the reference strains occurred for citric acid and succinic acid, but none were detected between strains for lactic acid content. Also, for glycerol, no statistical differences were detected between yeasts. The lowest amount of glycerol was detected for SB yeast (2.83 g/L). Increasing the word's density makes highlighting potential differences in the production of individual compounds between strains possible. These discrepancies can be seen, among others, in the ethanol content, where the highest content of this compound on a molasses word of 17.5 \({}^{\circ}\)Blg was measured for TD yeast--59.67 g/L (Table 3). Statistical analysis for ethanol revealed statistically significant differences between all tested yeasts. Of these, the smallest amount of ethanol was recorded for strain SB; the difference in ethanol concentration between this strain and TD was 13.63 g/L. Statistically significant differences can also be seen in the residual sugar content after fermentation. The highest concentrations of both glucose and fructose were measured for SB yeast. These amounted to 7.16 g/L for glucose and 22.28 g/L for fructose. The lowest amounts of both sugars were observed for TD yeast samples. The remaining glucose for this strain was 0.24 g/L, and for fructose was 1.43 g/L. For _S. boulardii_-fermented samples, the highest concentrations of lactic acid (3.13 g/L) and acetic acid (2.12 g/L) were noted. The citric acid content for all samples was 0.31-0.36 g/L. Similarly, in the case of succinic acid, the concentration for SB and ER yeast samples was close to 0.31 g/L. In the case of malic acid, the highest amount was recorded for the TD-fermented sample at 1.54 g/L. Analysis of the glycerol content of the samples tested shows statistically significant differences between the results obtained for SB yeast and the reference strains (ER, TD). The lowest amount of this compound was recorded for probiotic yeast at a concentration of 4.98 g/L, while the other two strains obtained results close to 5.7 g/L. A comparison of the results obtained on molasses words allowed for an assessment of the increase in ethanol production depending on the extract (Tables 2 and 3). Of the yeast tested, the smallest increase in ethanol production was recorded for the SB strain at 34.99%. The increase in this crucial compound for the other two yeasts was ER 42.25% and TD 47.70%. In both words, the highest concentration of sugars remaining after fermentation was noted for the probiotic strain. Organic acid analysis shows that SB yeast produced the highest amounts of lactic and acetic acids in both words (10 and 17 \({}^{\circ}\)Blg). This strain also produced the lowest glycerol in both words, but in the molasses word only of 17.5 \({}^{\circ}\)Blg; the difference in the content of this compound between the probiotic and the reference strain was statistically significant. The results obtained in the molasses words show that SB yeast manifested an underproduction of ethanol compared to the control distillers' yeasts ER and TD. The lack of fructose assimilation capacity of the SB yeast strain tested can explain these results. The results align with the literature on individual SB yeast strains' ability to assimilate compounds [4]. Literature data also report that _S.