## 3 Results and Discussion
### Chemical Analyses  
In Table 2, the standard enological parameters of the must before and after the completion of alcoholic fermentation are presented. The final concentration of total sugars was <4 g/L for each wine sample, 3.85 \(\pm\) 1.16 g/L for Zb-A19Y5, and 3.65 \(\pm\) 1.32 g/L for Zb-K29Y2 after 21 days, whereas for Tc-A9Y1, it was 1.00 \(\pm\) 0.00 g/L after 27 days. According to the chemical analysis results, _Z. buili_ strains, namely, Zb-A19Y5 and Zb-K29Y2, led to the production of wines with a high alcohol content (13.41 \(\pm\) 0.07%vol-13.11 \(\pm\) 0.05%vol). In contrast, the _T. californica_ (Tc-A9Y1) strain led to a reduced ethanol wine content (11.79 \(\pm\) 0.04%vol). Moreover, the yield of ethanol that was produced per unit of total sugar consumed (Y\({}_{\rm EtOH/TS}\), in g/g) was calculated. The ethanol yield of the two _Z. buili_ strains (0.45 and 0.44 g/g) was higher than those of _T. californica_ (0.39 g/g). Using the Zb-A19Y5 strain, the ethanol yield was 88% of the maximum theoretical yield (0.51 g/g). The use of strains that lead to low final sugar values and a high alcohol yield is mostly wanted in winemaking. In Assyrtiko must, _S. cerevisiae_ strains have also been tested with a higher alcohol yield (0.49-0.50 g/g) [53; 54]. An innovative strategy to produce reduced-alcohol wines takes advantage of wine yeasts that do not belong to the _S. cerevisiae_ species and that metabolize sugar without generating ethanol or do so with less efficiency [55].  
Furthermore, the pH value ranged between 3.12 \(\pm\) 0.01 and 3.19 \(\pm\) 0.01, with the highest value observed in the wine made with Tc-A9Y1. The total acidity of the wines ranged between 3.92 \(\pm\) 0.02 and 4.35 \(\pm\) 0.08 g tartaric acid/L, and yeast-assimilable nitrogen ranged between 99.40 \(\pm\) 0.74 and 105.70 \(\pm\) 3.01 mg N\({}_{2}\)/L, with the highest values observed in the wine made with Zb-A19Y5. The total SO\({}_{2}\) in wines made with _Z. buili_ strains showed the same values of 14.10 \(\pm\) 1.80 mg/L and 16.00 \(\pm\) 4.51 mg/L as those where _T. californica_ was inoculated. Low values of SO\({}_{2}\) indicate the need for further protection of the produced wines from oxidation. Additionally, even if the values of free and total SO  
Figure 3: Changes in total sugar consumption [D- glucose and D- fructose] during alcoholic fermentations for the two _Z. buili_ (Zb-K16Y1 and Zb-A19Y5) and one _T. californica_ (Tc-A9Y1) strain. Sample coding: Tc = _Trigonopsis californica_, Zb = _Zyosaccharomyces billi_.  
are not statistically significant, the higher value of combined SO2 of Tc-A9Y1 compared to _Z. bailii_ strains could be correlated to a lower fermentation rate and possible commitment with the produced acetaldehyde. No statistically significant differences were found between the values of yeast-assimilable nitrogen and sulfur dioxide, whereas L-malic acid was not detected in any of the samples. _Z. bailii_ is conventionally acknowledged as a malic acid-consuming yeast and has been suggested for adjusting pH in fermenting musts with an excess of malic acid [46; 56]. Regarding the volatile acidity, the values of acetic acid ranged between 0.41 \(\pm\) 0.02 and 0.47 \(\pm\) 0.01, with the highest value observed in the wine made with Tc-A9Y1. The levels in wines made with _Z. bailii_ strains were significantly different from those made with _T. california_, but comparable to those obtained from wines inoculated with _S. cerevisiae_ strains in Assyrtiko must [57].