); [EMAIL_ADDRESS] (G.K.); [EMAIL_ADDRESS] (C.R.-G.)  
[PERSON]  
Equipe VAlMS  
PAM UMR A 02.102 (L'Institut Agro Dijon, Universite Bourgogne Franche-Comte, F-Dijon), IUVV, 2 rue [PERSON], BP 27877, CEDEX, 21078 Dijon, France; [EMAIL_ADDRESS] (A.J. ); [EMAIL_ADDRESS] (G.K.); [EMAIL_ADDRESS] (C.R.-G.)  
[PERSON]  
Equipe VAlMS  
PAM UMR A 02.102 (L'Institut Agro Dijon, Universite Bourgogne Franche-Comte, F-Dijon), IUVV, 2 rue [PERSON], BP 27877, CEDEX, 21078 Dijon, France; [EMAIL_ADDRESS] (A.J. ); [EMAIL_ADDRESS] (G.K.); [EMAIL_ADDRESS] (C.R.-G.)  
[PERSON]  
Equipe VAlMS  
PAM UMR A 02.102 (L'Institut Agro Dijon, Universite Bourgogne Franche-Comte, F-Dijon), IUVV, 2 rue [PERSON], BP 27877, CEDEX, 21078 Dijon, France; [EMAIL_ADDRESS] (A.J. Among all non-_Saccharomyces_ yeasts, _Lachanca thermotolerans_ is of particular interest. Its unique ability to generate lactic acid as a coproduct of its sugar metabolism makes it very valuable for reducing the pH of wines, especially those from warmer viticulture areas [11]. In addition to this specificity, _L. thermotolerans_ also provides many other technical benefits for vinification, such as a lower sugar-to-ethanol yield [12], high glycerol production [13], and low acetic acid production [2; 11]. In addition, _L. thermotolerans_ can modulate volatile compound production in wine, since it is the only species amongst non-_Saccharomyces_ yeasts to potentially possess all the enzymes involved in aroma production. The following enzymes have been highlighted: lipases and esterases to produce esters from free fatty acids, aminopeptides to release the amino acid precursors of aromas, \(\beta\)-glucosidase to release terpen from precursors, and carbohydrates to degrade the cell walls of berries and release aroma precursors [14; 15]. Esters, terpenes, and higher alcohols confer fruity and floral notes to wine, thus leading to greater aroma diversity in the final product [2; 11; 14]. Moreover, interactions between _L. thermotolerans_ and _S. cerevisiae_ have already been described in the past, and both seemed to significantly impact fermentation results and vary depending on culture conditions [16; 17; 18]. This study therefore focused on _L. thermotolerans_ as the non-_Saccharomyces_ species of interest due to both its technical capabilities and its interactions with _Saccharomyces cerevisiae_. Studies by different authors on coformations between _S. cerevisiae_ (_Sc_) and _L. thermotolerans_ (_Lt_) showed variable impacts on products (ethanol production, acidification, the production of metabolites as aroma compounds, etc.) [19]. These inconsistent results can be explained by strain dependence and by the impact of environmental conditions. Factors such as medium composition, temperature, oxygenation, inoculation conditions, and so forth are indeed known to have an impact on yeast metabolism, on interactions between yeasts, and consequently on product quality. For example, [PERSON] et al. (2013) showed that the population dynamics observed and the aroma compounds produced within a mixed \(Sc/Lt\) culture varied with medium (must), batch volume, and temperature [16]. Other studies highlighted that oxygen played a significant role in the population dynamics [17; 20], and that both the amount and nature of nitrogen sources influenced global gene expression and thus impacted yeast growth, fermentation performance, and general metabolism [21; 22]. An inoculum ratio favoring one yeast or the other has also been shown to significantly impact the population dynamics over time, and then the volatile compound profiles as well [23]. However, these factors are often studied separately, and their impacts have been shown to change when other conditions vary [19]. It is thus necessary to standardize study conditions to obtain a better understanding of the mechanisms involved and to optimize wine fermentation with both non-_Saccharomyces_ yeasts and _S. cerevisiae_.