## 3 Results
### Minor Volatiles in Functional Katiki Domokou-Type Cheese
_Firmicutes_ were more abundant in the KFP and KIP samples compared to KC (\(p<0.05\)), and conversely, _Proteobacteria_ and _Bacteroideetes_ were in lower levels in the KFP and KIP than in the KC sample (\(p<0.05\)). Regarding _Actinobacteria_, no significant differences were observed between KC and KIP samples (\(p>0.05\)). However, _Actinobacteria_ were present in lower percentages in the KFP sample (\(p<0.05\)). At the genera level, _Lactococcus_ spp. was the most abundant genus (\(>\)78.7%) in all samples (\(p<0.05\)). Notably, lower percentages were observed in the KIP sample (78.71%) (\(p<0.05\)) compared to KC and KFP (87.49 and 92.77%, respectively). _Pediococcus_ genus was present, as expected, in cheese samples fortified with free or immobilized _P. acidilactici_ ORE5 with a relative abundance of 0.31 and 10.18% in the KFP and KIP, respectively, while in KC, it was detected in low levels (0.01%). Furthermore, the _Streptococcus_ genus was identified in relative abundance, ranging 0.74-3.11%, whereas in KFP and KIP, the levels were higher compared to the KC sample (\(p<0.05\)). _Lactobacillus_ spp. OTUS was higher  
Figure 1: Principal component analysis (PCA) of minor volatiles identified in the Katiki Domokou-type cheese samples containing free or immobilized _P. acidilactici_ ORE5 cells on pistachio nuts. KC—control samples, KFP—cheese samples containing free _P. acidilactici_ ORE5 cells, KIP—cheese with immobilized _P. acidilactici_ ORE5 cells on pistachio nuts. The storage duration (days) is shown at the end of the sample codes. in KIP (0.27%) compared to KC and KFP (\(p<0.05\)), while no significant differences were observed between KC and KFP samples (0.10% relative abundance in both samples). The genera _Chryseobacterium_, _Acinetobacter_ and _Pseudomonas_ were abundant in the KC sample (2.44, 1.57 and 1.29%, respectively) and were present in significantly lower percentages in KFP and KIP (\(p<0.05\)). Similarly, _Staphylococcus_, _Enhydrobacter_ and _Escherichia_ were detected at higher levels in KC (\(p<0.05\)) than in the KFP and KIP samples. Other genera (_Allobaculum_, _Alloococcus_, _Clostridium_, _Corynebacterium_, _Enterobacter_, _Enterococcus_, _Facklamia_, _Flavobacterium_, _Gluconacetobacter_, _Helicobacter_, _Janthobacterium_, _Jeotglicoccus_, _Macrooccus_, _Mannheimia_, _Methylobacterium_, _Oligella_, _Pedobacter_, _Prerotella_, _Propionibacterium_, _Psychrobacter_, _Salmonella_, _Splingobacterium_ and _Stentroplomonas_) were identified in low percentages (\(\leq\)0.08%). Of note, the genera _Facklamia_, _Flavobacterium_, _Salmonella_ and _Splingobacterium_ were present in the KC sample, while their presence was not detected in the KFP and KIP samples. Moreover, _Propionibacterium_ OTUS were higher in the KFP and KIP (0.06 and 0.08%, respectively) (\(p>0.05\)) than in the KC sample (0.03%). \begin{table}
\begin{tabular}{c c c c} \hline
**165 rRNA OTUs** & **KC** & **KFP** & **KIP** \\ \hline Shannon’s Index & 0.71 \(\pm\) 0.05 b\({}^{c}\) & 0.50 \(\pm\) 0.03 a\({}^{c}\) & 0.89 \(\pm\) 0.01 a\({}^{b}\) \\ Simpson’s Index & 0.23 \(\pm\) 0.02 b\({}^{c}\) & 0.14 \(\pm\) 0.05 a & 0.17 \(\pm\) 0.02 a \\ \hline \end{tabular} KC—control sample, KFP—cheese sample containing free _P. acidilactici_ ORE5 cells, KIP—cheese sample with immobilized _P. acidilactici_ ORE5 cells on pistacho nuts. All data represent the mean \(\pm\) standard deviation (SD) from two independent experiments. Significant differences: a (\(p<0.05\) vs. KC), b (\(p<0.05\) vs. KFP), c (\(p<0.05\) vs. KIP).  
\end{table} 
Table 7: Bacterial diversity indices Shannon’s and Simpson’s after 165 rRNA NGS sequencing in the Katiki Domokou-type cheese samples calculated using the Rhea platform and the a-diversity script. Figure 2: Relative abundances (%) of different bacteria phyla after 165 rRNA NGS sequencing in the Katiki Domokou-type cheese samples. All data represent the mean values from two independent experiments. KC—control samples, KFP—cheese samples containing free _P. acidilactici_ ORE5 cells, KIP—cheese with immobilized _P.