## 3 Results
### Microbial Growth Inhibition by Low-Concentration Essential Oils  
#### 3.2.1 Antifungal Activity  
The oregano EO formed an inhibition zone starting at a concentration of 5%, with larger inhibition zones found for F1 than for F2. The clove bud EO did not form an inhibition zone at any concentration. The thyme EO formed faint inhibition zones (0.2-0.3 mm), only at a concentration of 10%. The cinnamon cassia EO formed faint inhibition zones at a concentration of 3% and distinct inhibition zones \(\geq\) 5.8 mm at a concentration of 5%; the inhibition zones were notably larger against F2 than F1 (Table 3, Figure 3).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Source of EO**} & \multicolumn{6}{c}{**Inhibition Zone (mm)**} \\ \cline{2-7}  & **Strain F1** & **Strain F2** & **Strain B1** & **Strain B2** & **Strain B3** & **Strain B4** \\ \hline Eucalyptus & -* & -* & -* & 1.0 \(\pm\) 0.0 & 0.8 \(\pm\) 0.0 & 1.0 \(\pm\) 0.0 \\ Laverader & 0.3 \(\pm\) 0.0 & -* & 0.8 \(\pm\) 0.1 & 2.1 \(\pm\) 0.2 & 4.3 \(\pm\) 0.1 & 3.1 \(\pm\) 0.4 \\ Tea tree & 0.3 \(\pm\) 0.0 & -* & 0.8 \(\pm\) 0.2 & 5.4 \(\pm\) 0.1 & 5.3 \(\pm\) 0.5 & 3.2 \(\pm\) 0.2 \\ Peppermint & 0.4 \(\pm\) 0.1 & 3.8 \(\pm\) 1.2 & 0.9 \(\pm\) 0.1 & 3.8 \(\pm\) 0.0 & 4.0 \(\pm\) 0.2 & 3.4 \(\pm\) 0.3 \\ Oregano & 4.8 \(\pm\) 0.2 & 19.3 \(\pm\) 0.0 & 6.7 \(\pm\) 0.9 & 19.3 \(\pm\) 0.0 & 18.6 \(\pm\) 0.5 & 18.4 \(\pm\) 1.2 \\ Rosemary & -* & 1.0 \(\pm\) 0.8 & -* & 1.1 \(\pm\) 0.1 & 1.3 \(\pm\) 0.2 & 0.9 \(\pm\) 0.2 \\ Clove bud & 3.0 \(\pm\) 0.0 & 19.3 \(\pm\) 0.0 & 2.6 \(\pm\) 0.0 & 9.0 \(\pm\) 0.6 & 9.4 \(\pm\) 1.5 & 6.8 \(\pm\) 0.9 \\ Thyme & 4.3 \(\pm\) 0.0 & 19.3 \(\pm\) 0.0 & 7.5 \(\pm\) 0.4 & 19.3 \(\pm\) 0.0 & 19.3 \(\pm\) 0.0 \\ Grapfreruit & -* & -* & -* & 0.3 \(\pm\) 0.0 & 0.5 \(\pm\) 0.0 & 0.6 \(\pm\) 0.1 \\ Basil & 0.3 \(\pm\) 0.0 & -* & -* & 1.9 \(\pm\) 0.0 & 1.0 \(\pm\) 0.1 & 2.6 \(\pm\) 0.1 \\ Cinnamon cassia & 4.6 \(\pm\) 0.1 & 19.3 \(\pm\) 0.0 & 8.1 \(\pm\) 0.3 & 16.8 \(\pm\) 0.6 & 15.6 \(\pm\) 0.8 & 13.6 \(\pm\) 2.0 \\ Control (solvent) & -* & -* & -* & -* & -* & -* \\ \hline \hline \end{tabular}  
* *- <8 mm (strain is considered to be resistant to the essential oil). Data represent statistical differences in the antifungal and antibacterial activities of essential oils (pure) when \(p\leq\) 0.001.  
\end{table}
Table 2: Effect of tested essential oils (pure) on microbial strains isolated from Buyeo Royal Tomb No. 1.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Source of EO**} & \multirow{2}{*}{**Strains**} & \multicolumn{6}{c}{**Inhibition Zone (mm)**} \\ \cline{3-8}  & & **1\%** & **3\%** & **5\%** & **7.5\%** & **10\%** & **Distilled Water** & **Solvent** \\ \hline \multirow{8}{*}{Oregano} & F1 & -* & -* & -* & 1.2 \(\pm\) 0.5 & 2.0 \(\pm\) 0.7 & -* & -* \\  & F2 & -* & -* & 5.8 \(\pm\) 0.0 & 5.8 \(\pm\) 0.0 & 5.8 \(\pm\) 0.0 & -* & -* \\ \cline{1-1}  & B1 & -* & -* & 0.2 \(\pm\) 0.2 & 3.2 \(\pm\) 0.6 & 3.3 \(\pm\) 1.5 & -* & -* \\ \cline{1-1}  & B2 & -* & 1.3 \(\pm\) 0.1 & 3.3 \(\pm\) 1.2 & 7.5 \(\pm\) 0.4 & 9.2 \(\pm\) 1.6 & -* & -* \\ \cline{1-1}  & B3 & -* & -* & 2.1 \(\pm\) 0.5 & 5.1 \(\pm\) 1.7 & 5.9 \(\pm\) 2.3 & -* & -* \\ \cline{1-1}  & B4 & -* & 0.3 \(\pm\) 0.3 & 4.8 \(\pm\) 2.3 & 7.0 \(\pm\) 1.4 & 7.8 \(\pm\) 1.9 & -* & -* \\ \cline{1-1}  & F1 & -* & -* & -* & -* & -* & -* & -* \\ \cline{1-1}  & F2 & -* & -* & -* & -* & -* & -* & -* \\ \cline{1-1}  & B1 & -* & -* & -* & -* & 0.3 \(\pm\) 0.0 & -* & -* \\ \cline{1-1}  & B2 & -* & -* & 0.4 \(\pm\) 0.1 & 1.3 \(\pm\) 0.5 & 3.3 \(\pm\) 0.2 & -* & -* \\ \hline \hline \end{tabular}  
* *- <8 mm (strain is considered to be resistant to the essential oil). Data represent statistical differences in the antifungal and antibacterial activities of essential oils (pure) when \(p\leq\) 0.001.  
\end{table}
Table 3: Effect of tested essential oils (low concentration) on microbial strains isolated from Buyeo Royal Tomb No. 1.