## 3 Results
### Physiological Characterization of Non-Saccharomyces Ycasts
Figure 5: _Cont._  
Figure 5: Nonvolatile compounds in sterile juice compared with inoculated fermentations with candidate non-_Saccharomyces_ yeast strains with _S. cerevisiae_ BY4742 as control. UHPLC-RI was used to measure nonvolatile compounds in inoculated fermentation, sugars (glucose and fructose), ethanol, glycerol (**A**), and acids (malic acid, acetic acid, tartaric acid, citric acid, and succinic acid) (**B**). The different types of yeasts used in this study are represented on the x-axis. _S. cerevisiae_ BY4742 was used as a control. Data presented as mean ratio \(\pm\) SEM with a common superscript indicating significance (\(p<0.05\)). Figure 6: _Cont._  
Distinct Fermentation-Derived Volatile Metabolites Provide Insights into Unique Properties of Candidate Non-Saccharomyces Yeast from Chambourcin  
One aspect of wine quality is the contribution of fermentation-derived volatile compounds which can enhance sensory characteristics of final wine. Using GC-MS, 74 volatiles were identified when comparing sterile juice and inoculated fermentations and assigned to 11 classes based on their chemical structure (Figure S2). All 74 identified compounds were validated and included for further analysis (Table S2). Statistical differences of volatile compounds in inoculated fermentations are shown in Table S3. The correlation between volatile profiles and candidate yeast strains were analyzed by PLS-DA based on the identified volatile compounds. In total, 59.9% of the experimental variance was explained by the first three components, while components 1, 2 and 3 accounted for 20.8%, 21.3%, and 17.8%, respectively (Figure 7A-C). In the PLS-DA score plot, three components separated the inoculated fermentations into distinctive groups. Fifteen identified volatile compounds with the highest variable importance in projection (VIP) scores by PLS-DA can help explain volatile metabolite features driving separation between inoculated fermentations (Figure 7D). In this context, we interpret volatile compounds with high VIP scores as the most discriminant variables in PLS-DA. Here, we are most interested in features that differentiate candidate non-_Saccharomyces_ fermentations compared to _S. cerevisiae_ inoculated fermentations. For example, ionone (V42); 3-(methylthio)propyl acetate (V33); 2-heptanol (V9); 1-propanol, 3-(methylthio)- (V72); hexanoic acid, methyl ester (V23) were the most abundant compounds in inoculated fermentations with _Hanseniaspora_ strains PSWCC64 and PSWCC70 but had low abundance in _S. cerevisiae_ control strain. In addition, linalool (V53); acetin (V40); acetyl valaryl (V38); 2-butten-1-ol, 3-methyl-, acetate (V6); 3(2H)-Thiophene, dihydro-2-methyl- (V67) were also important features driving the differences of inoculated fermentation present with high intensity in _A. pullulans_ but low intensity in _S. cerevisiae_ control strain. On the contrary, two of the other important features,  
Figure 6: Nonvolatile compounds from inoculated fermentations differentiates from sterile juice. (**A**) PLS-DA scores plot and (**B**) loading plot of the variables with components 1 and 2 based on the nonvolatile composition of sterile juice (eight spoked asterisk) and inoculated fermentations with candidate yeast strains and _S. cerevisiae_ BY472. Each symbol in panel A represents a yeast strain and the ellipse around symbols represents a 95% confidence region of biological and technical triplicates. butanoic acid, 2-methyl- (V50) and octanoic acid, ethyl ester (V32), were present with high intensity in both _P. kudriazevii_ and _S. cerevisiae_. Next, we asked whether important features identified using the VIP scores plot were associated with particular strains or categories of metabolites. Based on [PERSON]'s correlation, we observed hierarchal clustering of 74 volatile metabolites against non-_Saccharomyces_ strains compared to _S. cerevisiae_ (Figure 8). Of particular interest is the group of metabolites associated with _P. kudriazevii_ but not with other strains.