## 4 Discussion  
Over the past decade, one of the major challenges has been researching and applying potential non-_Saccharomyces_ yeast starters and co-starters to improve the quality, aroma, and sensory characteristics of bakery products [7; 8; 25]. This study evaluated the suitability of the _P. terrestris_ strain PT22 AV for breadmaking in collaboration with Agroventures Srl. _Papilitotrema terrestris_ PT22 AV was used in co-culture with a commercial strain of _S. cerevisiae_ and a commercial formulation of the LAB starter _L. mesenteroides_. The potential of the strain in breadmaking is related to its ability to produce exopolysaccharides, as described by [PERSON] and [PERSON] [12]. Microbial-derived exopolysaccharides have numerous effects on bakery products. By binding with various chemical components in the dough, they can improve bread's structure, volume, and crumb softness, which reduces staling, and thus improves the shelf life of the product [26]. This  
Figure 5: Volatile organic compound distribution between different experimental breads after baking. Abbreviations: C1, control trial inoculated with _Leuconstoc mesenteroides_; C2, control trial inoculated with _Saccharomyces cerevisiae_; B1, trial co-inoculated with _L. mesenteroides_ and _Papilitotrema terrestris_; B2, trial co-inoculated with _S. cerevisiae_ and _P. terrestris_; B3, trial co-inoculated with _L. mesenteroides_, _P. terrestris_, and _S. cerevisiae_. research focused on evaluating the interaction between _P. terrestris_ PT22 AV and two commercial leavening agents, _S. cerevisiae_ and _L. mesenteroides_, under co-inoculation conditions. The monitored microbial populations revealed differences based on the inoculation method used for each trial. In the experimental doughs inoculated with _P. terrestris_ PT22 AV (B1, B2, and B3), yeast growth was observed only during the first 3 h of fermentation. A similar observation was reported by [PERSON] et al. [19] in doughs co-inoculated with _S. cerevisiae_ and _P. terrestris_, where the non-conventional yeast strain exhibited an increase in microbial cell density by approximately half a Log cycle after 2 h of fermentation. However, at subsequent detection points, the PT22 AV strain showed a decrease in levels, likely due to competition with the other starter strains. The decline in non-_Saccharomyces_ yeasts during dough fermentation is a common occurrence in co-inoculation with _S. cerevisiae._ [PERSON] et al. [27] observed a significant reduction in _T. delbrueckii_ (non-_Saccharomyces_) yeast during co-culture fermentation with _S. cerevisiae_, although the non-_Saccharomyces_ yeast remained viable. This phenomenon can be attributed to factors such as peptide production by _S. cerevisiae_[28] or spatial competition [29]. In our study, when _P. terrestris_ was co-inoculated with _L. mesenteroides_ (B1), the growth dynamics of the non-_Saccharomyces_ yeast showed a similar pattern to those in trials inoculated with _S. cerevisiae_ (B2 and B3), although microbial densities of the presumptive non-_Saccharomyces_ in B1 were higher than in the B2 and B3 trials. The early presence of _L. mesenteroides_ at high densities likely created a more favorable environment for _P. terrestris_[30]. The acidification dynamics of the doughs, measured by pH and TTA, were found to be influenced by the type of co-inoculum used. The presence of _L. mesenteroides_ in the C1, B1, and B3 trials resulted in a greater degree of dough acidification compared to the trials inoculated with yeasts (C2 and B2). The rapid acidification capacity of LAB is closely linked to the specific strain inoculated; however, this documented phenomenon creates a selective environment that can influence the final bread's characteristics [31]. The B3 trial, inoculated with a combination of _P. terrestris_, _S. cerevisiae_, and _L. mesenteroides_, exhibited the highest degree of acidification. The interaction levels between _Saccharomyces_, non-_Saccharomyces_, and LAB are complex.