## 4 Discussion
Of note, increased bacterial diversity can upgrade the nutritional value of fermented foods, given that different microorganisms, utilizing different metabolic pathways, are responsible for the formation of various metabolites, flavors and unique characteristics in the final product [49]. Regarding phyla, _Frimicutes_ was the predominant phylum in all cheese samples, while _Bacteroidetes_ and _Proteobacteria_ were in higher levels in the control cheese compared to the samples with _P. acidilactici_ ORE5 culture, in accordance with previous studies [47; 48]. At the genera level, _Pedicoccus_ were detected, as expected, in higher percentages in samples with free or immobilized _P. acidilactici_ ORE5 cells compared to the control. However, _Lactococcus_ was the most abundant genus in all samples, which may be attributed to the presence of _Lactococcus_ in cheese, as mesophilic lactic acid bacteria predominate during ripening and storage of cheese [11]. However, their relative abundance was significantly lower in cheese fortified with immobilized cells. Similarly, [PERSON] et al. [32] reported a significant decline in the levels of yogurt starter cultures in samples with _L. casei_ culture due to competitive activity of the probiotic strain. The fact that _Lactococcus_ was the most abundant genus in all samples contrasts the microbiological analysis results that demonstrated higher counts of lactobacilli compared to lactococci. This may be attributed to the ability of some _Lactococcus_ species to grow on MRS agar, and, therefore, not be easily distinguished from other cultures present on Petri dishes [50]. Consequently, it is possible some cultures belonging to the _Lactococcus_ genus were incorrectly enumerated as lactobacilli. Among other genera found in cheese, _Chryseobacterium_ was detected in the control cheese, while it was found at levels < 0.05% in samples with free and immobilized cells _Chryseobacterium_ are considered psychotropic spoilage bacteria and are usually detected in dairy products [51]. Similarly, _Pseudomonas_, which are considered aerobic psychotropic bacteria, were detectable in higher levels in the control cheese in contrast with KFP and KIP samples, where _Pseudomonas_ levels were below 0.02%. It has been reported that _Pseudomonas_ produce enzymes that may lead to spoilage due to their proteolytic activity [52]. Considering that Katiki Domokou cheese is made from goat's milk, the existence of _Acinetobacter_ in the control cheese may be explained, as _Acinetobacter_ is usually found in contaminated raw goat's milk [53]. Of note, in cheese samples fortified with free and immobilized cells, _Acinetobacter_ was found in significantly lower levels, which may be attributed to the potential antagonistic activity of _P. acidilactici_ ORE5 culture. Higher levels of _Staphylococcus_ were noted in the control cheese. Although not all _Staphylococcus_ are considered pathogens, _S. aureus_ is responsible for food poisoning due to production of enterotoxin [54; 55]. Moreover, _Enhydrobacter_ were detected in 0.17% relative abundance in control cheese, while their levels were 0.02% in the KFP and KIP samples. The existence of _Enhydrobacter_ is not commonly linked to cheese spoilage; however, some strains may have the potential to cause spoilage under certain conditions [32]. Relative abundance of _Sphinobacterium_, _Enterococcus_, _Facklamia_ and _Salmonella_ was recorded only in the control cheese,and their presence may indicate cheese spoilage. Likewise, _Flavobacterium_ was found only in the control cheese (KC), and it is considered part of natural cheese microflora, while some strains are associated with food spoilage [55]. Overall, NGS technology provides useful information about the microbiome composition of complex ecosystems like cheese, overcoming the limitations of the culture-dependent studies [48; 56].