## 3 Results
### BK510 Lys and AgNP-BK510 Lys Optimal Parameters  
The experiments were set up in three blocks, one for each temperature tested. Table 5 shows the lytic activities found for each experiment. The highest LA obtained, 2.69 \(\times\) 10\({}^{-3}\)\(\Delta\)OD/(s)(mg), was at pH 5, 30 \({}^{\circ}\)C and 0.14 mg/mL of BK510 Lys, while the lowest value, 0.46 \(\times\) 10\({}^{-3}\)\(\Delta\)OD/s*mg, was at pH 5, 40 \({}^{\circ}\)C and 0.07 mg/mL. While for AgNP-BK510 Lys, the highest LA obtained, 83.3 \(\times\) 10\({}^{-3}\)\(\Delta\)OD/(s)(mg), was at pH 9, 30 \({}^{\circ}\)C and 0.01 mg/mL of conjugate, while the lowest value, 0.09 \(\times\) 10\({}^{-3}\)\(\Delta\)OD/(s) (mg), was at pH 9, 40 \({}^{\circ}\)C and 0.07 mg/mL. Using the equations obtained from the regression analysis of BK510 Lys and AgNP-BK510 Lys data (equations 2 and 3, respectively), response surfaces were obtained for  
Figure 3: Samples of the cultures spread in Petri dishes with Luria Bertani medium, incubated at 37 \({}^{\circ}\)C for 24 h, tested at different ratios of AgNP-BK510 Lys: (**a**) _S. aureus_; (**b**) _Listeria_ sp. ; (**c**) _E. coli_; (**d**) _Salmonella_ sp. ; (**e**) _Klebsiella_ sp. ; (**f**) _P. vulgaris_; (**g**) _P. mirabillis_; (**h**) _P. aeruginosa_. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**System**} & **BK510 Lyss LA** & **AgNP-BK510 Lys LA** \\  & **(\(\Delta\)DO/(s)(mg)) \(\times\)10\({}^{-3}\)** & **(\(\Delta\)DO/(s)(mg)) \(\times\)10\({}^{-3}\)** \\ \hline
1 & 0.83 & 23.8 \\
2 & 0.46 & 45.9 \\
3 & 0.96 & 7.9 \\
4 & 0.68 & 0.9 \\
5 & 2.12 & 26.4 \\
6 & 2.28 & 81.2 \\
7 & 0.59 & 2.9 \\
8 & 0.67 & 7.7 \\
9 & 2.69 & 51.0 \\
10 & 0.72 & 83.3 \\
11 & 0.69 & 5.5 \\
12 & 0.53 & 15.4 \\
13 & 0.69 & 19.4 \\
14 & 0.69 & 11.0 \\
15 & 0.70 & 12.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: lytic activity of BK510 Lys and AgNP-BK510 Lys (2:1 ratio). different combinations of factors for the same response variable. The graphs are shown in Figure 4 (BK510 Lys) and Figure 5 (AgNP-BK510 Lys). \[ \begin{array}{c}\text{LA}=5.66173-0.094(\text{T})-0.092(\text{pH})-6.699(\text{ BK510 Lys})+0.002(\text{T})^{2}+\\ 0.001(\text{T})(\text{pH})-0.004(\text{T})(\text{BK510 Lys})-0.025(\text{pH})^{2}+ 0.423(\text{pH})(\text{BK510 Lys})+\\ 1.890(\text{BK510 Lys})^{2}\end{array}  \tag{2}\]  
\[ \begin{array}{c}\text{LA}=-22.1275+6.09583(\text{T})-12.6125(\text{pH})-157.338 (AgNP-BK510 Lys)-\\ 0.0192917(\text{T})^{2}-0.36375(\text{T})(\text{pH})-20.8333(\text{T})(AgNP- BK510 Lys)+1.83021(\text{pH})^{2}-\\ 46.6667(\text{pH})(AgNP-BK510 Lys)+4790.51(AgNP-BK510 Lys)^{2}\end{array}  \tag{3}\]  
The values to maximize the LA using the data obtained were:  
* BK510 Lys: pH5.00, temperature of 20.0 \({}^{\circ}\)C, and BK510 Lys concentration of 0.14 mg/mL, for a lytic activity of 2.74 \(\times\) 10\({}^{-3}\)\(\Delta\)DO/(s)(mg). * AgNP-BK510 Lys: pH 5.00, temperature of 39.9 \({}^{\circ}\)C, and BK510 Lys concentration of 0.01 mg/mL, for a lytic activity of 88.80 \(\times\) 10\({}^{-3}\)\(\Delta\)DO/(s)(mg). To determine if there was any significant effect of the factors studied, or some combination of these, an analysis of variance (ANOVA) was performed for the lytic activity. The ANOVA table (Tables 6 and 7 for BK510 Lys and AgNP-BK510 Lys, respectively) partitions the variability in LA into separate pieces for each of the effects. Figure 6 shows the Standardized Pareto Chart for BK510 Lys (a) and AgNP-BK510 Lys (b). As in the ANOVA, it is observed that there is one significant effect: BK510 Lys concentration and AgNP-BK510 concentration, respectively. Figure 4: Response surface for different factors interactions for BK510 Lys: (**a**) Temperature and pH; (**b**) pH and BK510 Lys concentration; (**c**) Temperature and BK510 Lys concentration.