## 4 Conclusions  
In this work, for the first time, the effect of dilution with water on the physicochemical and antimicrobial properties of lactic acid-based NADESs with choline chloride (NADES1), sorbitol (NADES2), and glucose, (NADES3) was systematically studied. Several physico \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multirow{2}{*}{**Water Content, \%**} & \multicolumn{3}{c}{_E. coli_} & \multicolumn{3}{c}{_P. aeruginosa_} & \multicolumn{3}{c}{_S. aureus_} \\ \cline{3-8}  & & **MIC** & **MBC** & **MIC** & **MBC** & **MIC** & **MBC** \\ \hline \multirow{8}{*}{NADES1} & 0 & 7.8 & 15.6 & 3.9 & 7.8 & 0.98 & 1.95 \\  & 10 & 15.6 & 31.3 & 7.8 & 15.6 & 1.95 & 3.9 \\  & 20 & 15.6 & 31.3 & 15.6 & 31.3 & 1.95 & 3.9 \\  & 30 & 31.3 & 62.5 & 15.6 & 31.3 & 3.9 & 7.8 \\  & 40 & 31.3 & 62.5 & 31.3 & 62.5 & 3.9 & 7.8 \\ \hline \multirow{8}{*}{NADES2} & 0 & 15.6 & 31.3 & 7.8 & 15.6 & 7.8 & 15.6 \\  & 10 & 15.6 & 31.3 & 7.8 & 15.6 & 7.8 & 15.6 \\  & 20 & 31.3 & 62.5 & 7.8 & 15.6 & 15.6 & 31.3 \\  & 30 & 31.3 & 62.5 & 15.6 & 31.3 & 15.6 & 31.3 \\  & 40 & 31.3 & 62.5 & 15.6 & 31.3 & 31.3 & 62.6 \\ \hline \multirow{8}{*}{NADES3} & 0 & 15.6 & 31.3 & 1.95 & 3.9 & 1.95 & 3.9 \\  & 10 & 15.6 & 31.3 & 3.9 & 7.8 & 1.95 & 3.9 \\ \cline{1-1}  & 20 & 31.3 & 62.5 & 7.8 & 15.6 & 3.9 & 7.8 \\ \cline{1-1}  & 30 & 31.3 & 62.5 & 15.6 & 31.3 & 3.9 & 7.8 \\ \cline{1-1}  & 40 & 31.3 & 62.5 & 31.3 & 62.5 & 7.8 & 15.6 \\ \hline Gentamicin & - & \(1\times 10^{-3}\) & \(2\times 10^{-3}\) & \(2\times 10^{-3}\) & \(4\times 10^{-3}\) & \(0.25\times 10^{-3}\) & \(0.5\times 10^{-3}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Antimicrobial activity of NADES without and after dilution with water (mg/mL). chemical parameters, including intermolecular interactions, density, pH, refractive index, viscosity, surface tension, and water activity, were evaluated. The formation of hydrogen bonds in NADES was confirmed using the FTIR method. After the dilution of NADESs with water, the strong hydrogen bonds weakened, however, were not destroyed after dilution with 40% water. The linear decrease in density and refractive index was observed for all NADES with the increase in water content. The dilution of NADES with water led to a statistically significant linear increase in pH. The equations for the prediction of NADES density, pH, and refractive index as a function of water content were calculated. A significant reduction in the viscosity of NADES was observed after the increase in water. The viscosity decreased by half after adding approximately 10% water. The initial viscosity of NADES2 and NADES3 containing different saccharides was significantly different. However, after adding 20% of the water, the viscosity was almost the same. The surface tension gradually and statistically significantly decreases after the dilution of all solvents. The most pronounced decrease in surface tension (by 46.7%) was found for NADES1. The calculated water activity of NADES3 was higher (\(a_{w}\) 0.097), followed by NADES1 and NADES2 with \(a_{w}\) 0.034 and \(a_{w}\) 0.031, respectively. The dilution of NADES with water caused a gradual increase in water activity. All the tested NADESs inhibited the growth of both Gram-positive and Gram-negative microorganisms. NADES1 showed the lowest MIC (7.8, 3.9, and 0.98 mg/mL) and MBC (15.6, 7.8, and 1.95 mg/mL) for _E.coli_, _P. aeruginosa_, and _S. aureus_, respectively. The Gram-positive opportunistic pathogen was more sensitive to all NADESs in the current study. The antimicrobial activity was correlated with water content in NADES and was decreased on average by 2-8 times after the addition of 40% water. We found that pH has a significant impact on antimicrobial activity. _S. aureus_ was the most sensitive to the pH of NADES. The water activity concept could be applied in predicting the growth of bacteria. The \(a_{w}\) for all tested NADESs together with low pH could explain the antimicrobial effect.