# Microbiota \"Fingerprint\" of Greek Feta Cheese through Ripening
## 4 Discussion
Although LABs are the main group of bacteria in all samples, there were differences noted between the third and the sixth month of ripening. _Lactobacillus pentosus, Lactobacillus delbrueckii, Lactobacillus fermentum_, and _Pediococcus pentosaceus_ have been detected only in samples of three months of ripening, while _Lactobacillus coryniformis, Leuconstoc fallax_, and _Pediococci (acidindicici_ and _parrulus_) were only detected in samples at six months of ripening. To determine the relationship between the bacterial species, a score-oriented MSPdendrogram was generated. Based on a distance level of 300, seven groups were present in both ripening periods (Figures 2 and 4). It is noteworthy that three bacteria in species level, such as _Lactobacillus brevis_, _Lactobacillus rhamnus_, and _Pediococcus pentosaceus_ belong to different clusters while only _Lactobacillus coruniformis_ belong to different clusters at the six-month period of ripening. _L. plantarum_, the most dominant species in the present study, were also isolated from Feta cheese by previous research [36], found to exert superior technological properties and contribute to the sensorial characteristics of the cheese. According to our results, _L. plantarum_ continue to be the predominant species after three and six months of ripening. Technological properties, including fast acidification and resistance to high salt concentration were observed also in the case of _Lactobacillus paracasei_, a dominant species in long-ripened cheeses like PDO Grana Padano [37], semi hard cheeses [38], and in brine-ripened cheeses like Teleme, Briaz, Haloumi, and Domiati [39]. _L. brevis_ are believed to thrive as the ripening evolves and contributes to the quality of the final product by producing biogenic amines [40]. _L.c. lactis_ were the only species of this genus isolated from the Feta cheese samples. They are considered a major contributor to the formation of the curd by fast acidification, while affecting the quality of the end product and particularly the moisture content and the cheese softness by their caseinolytic, aminopeptidase, and esterase lipase activities [41]. Finally, but equally important, Lc. lactis prevent the growing of pathogens and spoilage bacteria [42]. These results were in accordance with the findings of other researchers like [PERSON] et al. in the Turkish cheese Ezine, who studied selected LAB strains for their technological and antimicrobial properties against pathogenic or spoilage microorganisms [43]. Pediococci were not isolated from cheese samples as frequently as other LABs and the number of isolates of this genus confirm this. In our results, it should be noted that these bacteria (_Pediococcus pentosaceus_) were isolated from samples of three months ripening, while _Pediococcus acidilactici_ and _Pediococcus parulus_ have been detected in samples of six months ripening. Obviously, their importance is due to the fact that they contribute to the organoleptic profile (flavor) of the cheese by the production of diacetyl and acetaldehyde. They also exert a proteolytic activity against peptides containing a proline group [44]. The only _Leuconstoc_ species was _L. fallax_ (1 strain), isolated from six-month Feta cheese samples. (Table 3). This species is heterofermentive, resistant to 5% salt concentration and can grow in pH values as low as 3.9 [45]. _Leuconstoc_ species produce polysaccharides contributing to the texture and stabilization of the cheese [46], while they are aroma producers [47]. _Entrococci_, as a group are very often isolated from various types of cheese made of ovine or caprine milk, Feta among them [48] and particularly in brine-ripened cheeses. In our study, four species have been detected, such as _Enteroococcus durans_, _Enterococcus ficeum_, _Enterococcus faecalis_, and _Enterococcus malodoratus_. More than 30 species of the _Enterococcus_ genus have been isolated from dairy products, yet there are not of the same technological capacity. _E.