## 4 Discussion  
Four traditional Apulian cheees (Caprino, Pecorino, Vaccino, Cacioricotta), manufactured at the same dairy plant, were analyzed to highlight their distinctive traits. The influence of house microbiota on cheeses' traits [36] was minimal because the same equipment and ripening rooms were used for all the cheeses. Yet, the experimental plan suffered from one main limitation, represented by the limited number of samples for each cheese, which hinders gaining a collective overview on each TAP cheese. The gross composition of the cheeses approached that previously reported for similar types of cheese [37; 38; 32]. Cacioricotta cheese retained the highest percentage of sodium chloride, in agreement with previous studies [39]. High salt concentration in Cacioricotta could account for its relatively high content in carbohydrates, with special regard to lactose, which was only detected in this cheese. Indeed, the high salt concentration in Cacioricotta may have slowed down lactose catabolism of LAB [40], as reflected by the lowest concentration of lactic acid and highest pH value of the Cacioricotta cheese subjected to study. Although the highest salt concentration was found in Cacioricotta, this cheese was  
Figure 5: Main distinctive traits (compositional, metabolites, microbiological, enzymatic activities) of Caprino, Pecorino, Vaccino, and Cacioricotta TAP cheeses produced at the same dairy plant. Pointed-up and pointed-down arrows flanking each trait indicate high and low values, respectively. Abbreviations: FFA, free fatty acids; GDH, glutamate dehydrogenase activity. characterized by the highest value of A\({}_{\rm w}\). This important cheese parameter is affected not only by salt concentration [41] but also by water content and concentration of proteolysis products [42; 43; 44]. We may hypothesize that the highest value of A\({}_{\rm w}\) found in Cacioricotta could be due to the shorter ripening time of this cheese (9 months), compared to that applied for the other cheeses (12 months), as well as to low aptitude to syneresis observed for curds originating from milk treated at 90 \({}^{\circ}\)C (as was the case for Cacioricotta cheese) [45]. In addition, the low concentration of proteolysis products estimated in this cheese could have determined higher values of A\({}_{\rm w}\), compared to the other cheeses, showing higher proteolysis levels. Based on culture-dependent analysis using selective agar media (e.g., MRS, lactose-M17, Slanetz and Bartley), LAB (especially mesophilic) dominated the microbiota of the four cheeses, the object of study. Furthermore, staphylococci represented an additional dominant microbial population in Cacioricotta. _Enterobacteriaceae_ and yeasts represented minority microbial populations of cheeses. The use of NWS cultures during the manufacturing of two cheeses (Caprino and Vaccino) only slightly affected the microbial community of those cheeses. This result could be explained considering that most LAB inoculated in cheese milk through the addition of starter cultures declines throughout ripening [46]. Culture-independent analysis showed that _L. helveticus_ dominated the bacterial biota of both the NWS (CNWS and VNNS) cultures and the corresponding Caprino and Vaccino cheeses. _L. helveticus_ is a thermophilic LAB species, capable of growing at 45 \({}^{\circ}\)C, commonly inhabiting NWS cultures, alone or together with _S. thermophilus, Lactobacillus delbrueckii_, and _L. fermentum_[6; 47; 48]. We may hypothesize that _L. helveticus_, originating from NWS cultures, adapted its physiology [49] during the cooking step (45 \({}^{\circ}\)C for 10-40 min) of Caprino and Vaccino curds. Then, it survived scaling (a few seconds at 80-85 \({}^{\circ}\)C) and probably dominated cheese microbiota during the first days of ripening [46]. It is probable that, although _L.