# New Isolated Autochthonous Strains of _S. cerevisiae_ for
## 3 Results and Discussion
### Isolation and Genetic Identification of Native Yeast and Determination of their  
_Fremntative Potential_  
A total of 19 yeast strains were isolated in vineyards of the Swietokrzyskie (southeastern) and Lubuskie (western) voivodeships of Poland, 11 of which were identified as _Saccharomyces cerevisiae_ (non-commercial strains, NCS). The remaining eight strains were identified as wild yeasts belonging to the species _Hanseniaspora uvarum_ and the genus _Metschnikowia_ (Table 1). The sequences of the strains isolated from the vineyards have been deposited in the GenBank database (Table 1) and the microorganisms have been deposited in the Culture Collection of Industrial Microorganisms-Microbiological Resource Center of the Department of Microbiology, Prof. [PERSON] Institute of Agricultural and Food Biotechnology State Research Institute. Among the newly isolated yeast strains, only nine NCS (from 1_NCS to 9_NCS) showed fermentation potential (alcohol content above 4.00%) (Table 2). The remaining seven strains used in the study were commercial strains (CS) that were certified by the manufacturer as strains intended for winemaking (various strains of the species _S. cerevisiae_). The maximum alcoholic fermentation efficiency was observed in the sample fermented with the yeast strain 1_NCS (5.894 \(\pm\) 0.010%). All commercial strains were characterized by high fermentation capacity (alcohol content in the samples ranging from 5.548 \(\pm\) 0.012 to 5.810 \(\pm\) 0.024%). Statistically significant differences were found during the test fermentations between the mean pH of sample 19_NCS (lowest pH) and samples 1_NCS, 2_NCS, 7_NCS, 1_CS (highest pH). Total acidity in the trial process was about 3-5 g of malic acid L. A visible \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Strain Symbol**} & \multicolumn{2}{c}{**Isolation Source**} & \multicolumn{2}{c}{**Yeast Identification Acc.**} & \multirow{2}{*}{**Yeast Strain Number**} & \multirow{2}{*}{**GenBank No.**} \\ \cline{2-2} \cline{6-6}  & **Voivodship** & & & & **Grape Varieties** & **to 265 rRNA Sequencing** \\ \hline  
\hline \multicolumn{2}{c}{} & commercial strain & & _Sachcharomyces cerevisiae_ * & \\ \hline
6\_CS & commercial strain & & _Sachcharomyces cerevisiae_ * & \\ \hline
7\_CS & commercial strain & & _Sachcharomyces cerevisiae_ * & \\ \hline \hline \multicolumn{2}{c}{} & commercial strain & & _Sachcharomyces cerevisiae_ * & \\ \hline \multicolumn{2}{c}{} & commercial strain & & _Sachcharomyces cerevisiae_ * & \\ \hline
6\_CS & commercial strain & & _Sachcharomyces cerevisiae_ * & \\ \hline
7\_CS & commercial strain & & _Sachcharomyces cerevisiae_ * & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Ethyl alcohol content, total acidity and pH after fermentation of test settings. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Strain Symbol**} & \multicolumn{2}{c}{**Ethanol**} & \multirow{2}{*}{**Total acidity**} & \multirow{2}{*}{**Strain Symbol**} & \multirow{2}{*}{**Ethanol**} & \multirow{2}{*}{**Total acidity**} \\  & [\%]* & & & **gmail acid/d1** & & **gmail \\ \hline
1\_NCS & 5.894 \(\pm\) 0.001* & 3.66 \(\pm\) 0.02* & 4.449 \(\pm\) 0.240 & 14\_NCS & 0.178 \(\pm\) 0.005* & 3.47 \(\pm\) 0.01* & 15.36 \(\pm\) 0.083 \\ \hline
2\_NCS & 5.826 \(\pm\) 0.012* & 3.68 \(\pm\) 0.02* & 4.529 \(\pm\) 0.245 & 15\_NCS & 2.325 \(\pm\) 0.005* & 3.61 \(\pm\) 0.02* & 3.055 \(\pm\  
deviation from the rest of the results was observed for the 14_NCS strain and was 1.536 g malic acid/L. This strain was the only one isolated from material other than fruit or vine leaves (the soil under the bush of the Seyval blanc variety). It is not able to carry out alcoholic fermentation, but due to the significant reduction in total acidity, it can potentially be used in the biological de-acidification of wines. Further research is required to confirm this property.