## 3 Results and Discussion
### In Vitro Antimicrobial Activity  
In the present study, the DDM, as a simple, low cost, rapid, and well-known antimicrobial screening procedure [31], was used to compare the growth-inhibitory activity of the Azorean _C. japonica_ EOs, EO components (\(\alpha\)-pinene and terpinen-4-ol), and antimicrobial drugs (Kanamycin and Nystatin) against the selected microorganisms, as illustrated in Table 3.  
All the studied EOs showed weak to moderate antibacterial activity against Gram-positive bacteria as compared to the positive control (inhibition zones of 7-13 mm and 30-39 mm, respectively). However, there is no significant difference in antimicrobial activity between the studied plant parts regarding these bacteria, namely, _B. subtilis_ (\(F\) = 1.12;  
Figure 2: Gas chromatography with flame ionization detection profiles, taken on the DB-1 column, of the essential oil from different Azorean _Cryptomeria japonica_ parts: (**A**) female cones, (**B**) male cones, (**C**) leaves, and (**D**) foliage. \(df=3\); \(p=0.392\)), _B. licheniformis_ (\(F=1.26\); \(df=3\); \(p=0.351\)), and _M. luteus_ (\(F=2.40\); \(df=3\); \(p=0.135\)), as we can see in Figure 3. Moreover, all the studied EOs were inactive against Gram-negative bacteria. Previous reports [9] on antibacterial activity of foliage EOs obtained by SD from Azorean _C. japonica_ samples revealed no activity against _B. subtilis_ and _E. coli_. However, it should be noted that the comparison of antimicrobial efficacy data between studies is difficult when different raw material, microbial strains, antimicrobial evaluation methods, and experimental conditions (e.g., culture medium, amount of EO tested, and incubation conditions) were used, among other factors [32]. Our results also revealed that the antibacterial action of the studied EOs is in accordance with their major component, \(\alpha\)-pinene, that also exhibited superior efficacy against Gram-positive bacteria over negative ones (inhibition zones of 14-18 mm and 7-8 mm, respectively), possibly due to the difference in the cell wall structures of the two bacteria groups. Indeed, Gram-negative bacteria have an outer membrane rich in lipopolysaccharideacharide molecules, which hinder the entry of hydrophobic components into the bacterial cell [33]; thus, Gram-positive bacteria, which lack this outer membrane, were found to be more sensitive to the studied EOs and pure \(\alpha\)-pinene when compared with the negative ones. A similar trend was reported by other researchers investigating the antimicrobial activity of other EOs [10; 15]. However, this pattern is not always observed for all EOs/EO molecules, as documented in the review by [PERSON] et al. [34] and in the present study. Indeed, contrary to \(\alpha\)-pinene action, the oxygen-containing monoterpene terpinen-4-ol was more effective against Gram-negative bacteria than Gram-positive bacteria (inhibition zones of 19-31 mm and 7-11 mm, respectively). According to the literature, terpinen-4-ol has gained attention for its potential as a broad-spectrum antibacterial agent [35] for therapeutic application. For example, a recent study [36] showed that this compound has strong bactericidal activity against _Staphylococcus aureus_, probably by interfering with the synthesis of the bacterial cell wall, resulting in the loss of cytoplasmic material. Interestingly, the present study revealed that the studied EOs, even the MC EO, which presented the highest terpinen-4-ol content (12%), were inactive against all the selected Gram-negative bacteria, as mentioned above. This indicates the possibility of an antagonistic interaction between terpinen-4-ol and other Azorean _C. japonica_ EO components in the antibacterial effect, which should be considered for further investigation. Regarding the antifungal activity, only the EOs from FCs and MCs were slightly active against _P. chrysogenum_, probably due to the higher concentration of monoterpene hydrocarbons and oxygen-containing monoterpenes in the EOs from these plant parts.