## 3 Results
### Antibacterial Activity  
The antibacterial properties of the tested _G. hederacea_ extracts, expressed as MIC and MBC values, against Gram-positive and Gram-negative bacteria, are presented in Table 3. All tested extracts exhibited the inhibition of indicator bacteria; however, the results depended on both the bacterial strain and the sample extraction temperature. The strongest antagonistic effect was observed for the herb extract obtained at 40 \({}^{\circ}\)C/250 bar for most of the Gram-positive bacteria and one of the tested Gram-negative species. Stronger antibacterial properties were detected mainly in relation to Gram-positive bacteria, whereas the effect was weaker in relation to Gram-negative bacteria. MIC ranged from 0.3 to \(>\)5.0 mg/mL for Gram-positive bacteria, and from 1.25 to 2.5 mg/mL for Gram-negative bacteria, whereas MBC ranged from 0.6 to \(>\)5 mg/mL and from 2.5 to 5.0 mg/mL, respectively. The MIC values for all extracts against Gram-positive _M. luteus_ (1.25 mg/mL), as well as Gram-negative _P. aeruginosa_ (2.5 mg/mL) and _E. coli_ (2.5 mg/mL), were the same for all the different extraction temperatures. The strongest antibacterial activity was observed towards _S. aureus_ with an MIC of 0.3 mg/mL and an MBC of 0.6 mg/mL for the _G. hederacea_ extract obtained at 40 \({}^{\circ}\)C/250 bar. Among Gram-negative bacteria, the strongest inhibition of bacterial growth was observed for _P. aeruginosa_ for all tested extracts. \begin{table}
\begin{tabular}{c c c c} \hline
**Extraction** & **DPPH** & **ABTS** & **FRAP** \\
**Conditions** & **(\%)** & **(\(\mu\)g TE/g)** & **(\(\mu\)mol TE/g)** \\ \hline
40 \({}^{\circ}\)C & 56.48 \({}^{\mathrm{a}}\) \(\pm\) 3.98 & 36.58 \({}^{\mathrm{a}}\) \(\pm\) 1.20 & 18.15 \({}^{\mathrm{a}}\) \(\pm\) 0.21 \\
50 \({}^{\circ}\)C & 25.74 \({}^{\mathrm{b}}\) \(\pm\) 0.43 & 7.60 \({}^{\mathrm{b}}\) \(\pm\) 0.69 & 13.06 \({}^{\mathrm{b}}\) \(\pm\) 0.04 \\
60 \({}^{\circ}\)C & 22.21 \({}^{\mathrm{c}}\) \(\pm\) 0.39 & 4.66 \({}^{\mathrm{c}}\) \(\pm\) 0.12 & 12.88 \({}^{\mathrm{b}}\) \(\pm\) 0.07 \\ \hline \end{tabular} Values are mean \(\pm\) standard deviation, n = 3, values with the same lowercase letters in the same column indicate no significant difference at the level of 5% (\(p<0.05\)).  
\end{table} 
Table 2: Antioxidant activities estimated via DPPH, ABTS and FRAP assays of _G. hederacea_ extracts. Figure 1: Correlation between TPC and (**a**) FRAP, (**b**) ABTS and (**c**) DPPH results of _G.hedranca_ extracts. The antibacterial potential of _G. hederaca_ extracts obtained by SC-CO\({}_{2}\), depending on the process conditions, has not been established in the literature; however, the influence of different extraction conditions of SC-CO\({}_{2}\) on the antibacterial activity of plant extracts is well described. [PERSON] et al. (2019) [60] studied the biological activity of SC-CO\({}_{2}\) guayusa leaf (_llex guayusa_ Loes.) extracts obtained with differentiated process conditions. The authors tested, among others, antibacterial properties against _B. subtilis_, _S. aureus_, _E. coli_ and _P. aeruginosa_. On the contrary to the results obtained in the studies with guayusa leaves, the lower extraction temperature of _G. hederaca_ extracts resulted in higher antibacterial properties for most of the bacterial strains. The obtained results indicate the influence of the different extraction temperatures of SC-CO\({}_{2}\) on the total polyphenol composition of _G. hederaca_ extracts and consequently on the antibacterial activity. [PERSON] et al. (2008) [61] determined antimicrobial activity of SC-CO\({}_{2}\) extracts of green alga (_Dunaliella salina_) obtained using different extraction parameters against _E. coli_, _S. aureus_, _C. albicans_ and _Aspergillus niger_. The results showed that all tested alga extracts presented antimicrobial activity against selected bacteria and yeasts.