## 4 Discussion
Data are reported as mean value \(\pm\) standard deviation and [PERSON]’s test (\(p\)-value \(<\) 0.05) reported as different superscript letters (\({}^{\mathrm{a,b,c}}\)) within each row represent significant differences. cellars, enhancing the aroma qualities of the wine-production area [25]. However, the occurrence and effects of regional/winery specific microbiota in defining wine characteristics are more controversial issues [26; 27]. Several studies using high throughput sequencing technologies described microbial communities of grapes and related wines and winery, revealing a link between grape must and soil microbial communities, as well as the geography of the territory [28; 29; 30]. Other studies showed that there are no specific strains representative of a winery or a winemaking area [4; 31; 32]. In addition, two vineyards can share a very similar yeast consortium at the genus or species level but may be very different at the strain level since the strong strain's differences may produce very different wines [33; 34; 35]. Based on these observations, the concept of \"microbial terror\", although its meaning seems more complex, involves many factors, related to both the plant and the physical environment. Based on this, terror must be considered by a pluri-disciplinary approach. Another aspect regarding the concept of \"winery effect\" are the overall selective factors as winery environment, fermented grapes, and winemaking methodologies. [PERSON] [36] showed that in a new winery after the initial addition of selected _S. cerevisiae_, it is able to impose itself on the spontaneous fermentation carried out the next year. In another work [37], the selectivity of the winery environment (\"winery effect\") was detected between the _S. cerevisiae_ population isolated from a modern, working winery, and an abandoned one (since 1914). The _S. cerevisiae_ yeasts population from a modern winery showed higher values for characters typically subjected to selective pressure (fermentation power, fermentation rate, SO\({}_{2}\) resistance). Today, there still remains a lacking concern in the origin and colonization of _S. cerevisiae_. It is very rare on grape and vineyard but was found on damaged grapes [38]. It drives spontaneous fermentation carried out in sterilized vessels [39] and it is also widely found colonizing winery surface and winery equipment (also in a newly built winery) for several years [40; 41]. In the present work, the _S. cerevisiae_ populations of two wineries located in the same winemaking area (Verdichio DOC Castelli di Jesi) were evaluated with the same methods of conducting fermentation (never used commercial strains, use of spontaneous fermentations with pre-inoculum). A distinct and stable _S. cerevisiae_ yeast population was found in both wineries. Some specific genotypes were dominant in each winery in two years (95% and 20% of isolates in winery 1 and winery 2, respectively) confirming the results reported by other authors [7; 11; 42]. These results may be an additional support for the so called \"winery effect\" or a microbial terroir at a smaller scale as suggested by other works [7; 42; 43; 44] where some predominant _S. cerevisiae_ strains persisted in different fermentations in the same winery from one year to another and they seemed to be representative of a single winery rather than of an oenological area. Moreover, in agreement with [PERSON] et al. [45], the results of the PCA analysis of oenological characters of the _S. cerevisiae_ population showed distinctive aromatic profiles in each winery population suggesting the possible existence of a winery-specific \"microbial-terroir\" that may contribute to the final product. However, the variability due to the harvest (\"year effect\") can also play an important role in the presence and variability of the biotypes and ultimately on their contribution to the final product.