## 3 Results and Discussion
### Antimicrobial Activity of GEs
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**GEs Synthesized Using FAMEs (at 40 ug/mL) Derived From:**} \\ \cline{2-7}  & _C. echinulata_ & _U. isabellina_ & _N. gaditana_ & **Olive Oil** & **EPA Concentrate** \\ \hline \multicolumn{7}{c}{**Inhibition Zone (mm)**} \\ \hline _Escherichia coli_ & 9.4 \(\pm\) 0.3 & 0.0 & 10.0 \(\pm\) 0.4 & 11.5 \(\pm\) 0.4 & 11.1 \(\pm\) 0.0 \\ (ATCC 25922) & & 10.5 \(\pm\) 0.5 & 0.0 & 11.1 \(\pm\) 0.4 & 10.3 \(\pm\) 0.6 & 14.2 \(\pm\) 0.1 \\ _Klebsiella pneumoniae_ & & 10.5 \(\pm\) 0.5 & 5.8 \(\pm\) 0.7 & 6.1 \(\pm\) 0.3 & 10.1 \(\pm\) 0.7 & 15.0 \(\pm\) 0.0 \\ (ATCC 14028) & & 6.8 \(\pm\) 0.8 & 5.5 \(\pm\) 0.8 & 10.5 \(\pm\) 0.5 & 10.1 \(\pm\) 0.4 & 13.2 \(\pm\) 0.0 \\ _Bacillus subtilis_ & & & & & & \\ (ATCC 6633) & & 14.1 \(\pm\) 0.5 & 0.0 & 9.0 \(\pm\) 0.0 & 9.8 \(\pm\) 0.7 & 17.0 \(\pm\) 0.5 \\ MRSA _Staphylococcus aureus_ & & 11.2 \(\pm\) 0.1 & 5.8 \(\pm\) 1.0 & 8.5 \(\pm\) 0.5 & 10.1 \(\pm\) 0.2 & 16.0 \(\pm\) 0.1 \\ (ATCC 25923) & & 12.3 \(\pm\) 0.2 & 0.0 & 8.6 \(\pm\) 0.3 & 12.0 \(\pm\) 0.6 & 17.0 \(\pm\) 0.2 \\ _Candidia albicans_ & & & & & & \\ (ATCC 10231) & & 14.3 \(\pm\) 0.0 & 13.3 \(\pm\) 0.0 & 14.0 \(\pm\) 0.0 & 15.0 \(\pm\) 0.3 & 20.0 \(\pm\) 0.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: GEs’ antimicrobial activity using human pathogens as test organisms. Data represent the mean of three replicates \(\pm\) SD of the diameter of the inhibition zones. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Source of FAMEs**} \\ \hline \hline
**Test organisms** & \multicolumn{2}{c}{_C. echinulata_} & \multicolumn{2}{c}{_N. gaditana_} & \multicolumn{2}{c}{**Olive Oil**} & \multicolumn{2}{c}{**EPA Concentrate**} \\ \hline \hline  & **MIC** & **MBC** & **MIC** & **MBC** & **MIC** & **MBC** & **MIC** & **MBC** \\ \hline _Klebsiella pneumoniae_ & & & & & & & \\ (ATCC 700603) & 25.0 \(\pm\) 0.0 & 100.0 \(\pm\) 0.0 & 50.0 \(\pm\) 0.0 & 100.0 \(\pm\) 0.0 & 66.7 \(\pm\) 28.8 & 83.3 \(\pm\) 28.8 & 33.3 \(\pm\) 14.4 & 100.0 \(\pm\) 0.0 \\ _Pseudomonas aeruginosa_ & & & & & & & \\ (ATCC 15442) & & 100.0 \(\pm\) 0.0 & 50.0 \(\pm\) 0.0 & 100.0 \(\pm\) 0.0 & 25.0 \(\pm\) 0.0 & 83.3 \(\pm\) 28.8 & 20.8 \(\pm\) 7.2 & 41.7 \(\pm\) 14.4 \\ _Bacillus subtilis_ & & & & & & \\ (ATCC 6633) & & 16.7 \(\pm\) 7.3 & 50.0 \(\pm\) 0.0 & 20.8 \(\pm\) 7.3 & 100.0 \(\pm\) 0.0 & 33.3 \(\pm\) 14.4 & 100.0 \(\pm\) 0.0 & 10.4 \(\pm\) 3.6 & 41.7 \(\pm\) 14.4 \\ _Staphylococcus aureus_ & & & & & & & \\ (ATCC 25923) & & 12.5 \(\pm\) 0.0 & 50.0 \(\pm\) 0.0 & 50.0 \(\pm\) 0.0 & 83.3 \(\pm\) 28.8 & 83.3 \(\pm\) 28.7 & 100.0 \(\pm\) 0.0 & 8.3 \(\pm\) 3.6 & 33.3 \(\pm\) 14.4 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Minimum inhibitory concentration (MIC, ug/mL) and minimum bactericidal concentration (MBC, ug/mL) of the synthesized GEs against pathogens. increased. It seems that the carbon chain length was the most important factor influencing the surface properties, whereas the degree of esterification and hydrophilic groups showed little effect [61]. The antimicrobial activity of glucose esters was tested against _E. coli_, _B. subtilis_, _B. megaterium_ and _B. cereus_[51; 56]. In addition, the unsaturated FAs' lactose esters were shown to exhibit antimicrobial activity against Gram-positive and Gram-negative microorganisms and fungi [5]. The antimicrobial activity of SEs is due to autolysis caused by the interaction of the esters with cell membranes of bacteria. The lytic action is thought to be due to the activation of autolytic enzymes rather than the actual solubilization of the bacterial cell membrane [62]. The FAAs synthesized in [PERSON] et al. [36] using lipids with a similar FA composition as acyl group-donors to those used in this paper also exhibited significant antimicrobial activity. However, contrary to the results reported here, the FAAs containing oleic acid in high percentages (i.e., derived from olive oil and _U. isabellina_ oil) were more effective against human pathogens than other FAAs.