## 3 Results and Discussion
### The Effect of Fir Honeydew Honey on Bacterial Growth and Cell Structure  
In order to determine the effect of FHH on bacterial growth, solutions containing 5% [\(w/v\)] and 3% [\(w/v\)] of FHH in MH broth and milk were prepared. As expected, a higher concentration of FHH had a stronger effect on the growth of _C. jejuni_ NCTC 11168 and _C. jejuni_ K49/4 in the MH broth and milk. FHH at a concentration of 5% [\(w/v\)] completely inhibited the growth of _C. jejuni_ NCTC 11168 in MH broth and milk at each time point (Tables 2 and 3). At the lower concentration (3% [\(w/v\)]), a statistically significant effect was not observed after 24 h of incubation in MH broth (Table 2). After 24 h incubation in milk, to which FHH (3% [\(w/v\)]) was added, the growth of _C. jejuni_ NCTC 11168 was reduced by 74.4 \(\pm\) 8.3% (Table 3). There was a significant effect of FHH on the growth of _C. jejuni_ K49/4 in MH broth and milk at the concentration of 5% [\(w/v\)], but the lower concentration (3% [\(w/v\)]) showed no inhibitory effect on the growth of _C. jejuni_ K49/4 in MH broth and milk (Table 3). \begin{table}
\begin{tabular}{c c c} \hline \multicolumn{3}{c}{**MIC (mg/mL)**} \\ \hline
**Bacterial Strain** & **MH Broth** & **Milk** \\ \hline _C. jejuni_ NCTC 11168 & 12.5 & 25 \\ _C. jejuni_ K49/4 & 25 & 50 \\ \hline \end{tabular}
\end{table} 
Table 1: Minimal inhibitory concentration (MIC) of fir honeydew honey aginst bacteria _Campylobacter jejuni_ NCTC 11168 and _C. jejuni_ K49/4 determined in Mueller Hinton (MH) broth and milk. _c. jejuni_ NCTC 11168 was more sensitive compared to _C. jejuni_ K49/4. _C. jejuni_ K49/4 is a strain isolated from heat-treated poultry meat, which could be the reason why this strain has a better stress response than _C. jejuni_ NCTC 11168 [31]. Many antimicrobial substances in honeydew honey, including hydrogen peroxide and various polyphenols, as well as their interactions [50; 51; 52; 53; 54], can affect the growth of _C. jejuni_. The effect of FHH in milk was as good as in MH broth (Table 3). Milk contains various bioactive peptides [55], which can improve the antibacterial effect of honey. Milk also contains smaller peptides that can diffuse rapidly into the cell membrane and cause cell leakage. Immunological peptides in milk can also reduce the growth of bacteria [56]. Inhibition of _C. jejuni_ growth after the addition of FHH was the consequence of stress, which includes osmotic stress and stress caused by the antimicrobial agents to which bacteria were exposed [52]. This was confirmed using TEM (Figure 1), which showed that FHH induced morphological changes in bacterial cell shape similar to those found by [PERSON] and [PERSON] [53] on _Camyylobacter_ cells after exposure to stress conditions. The changes caused by FHH are shown in Figure 1B,C. A concentration of 1\(\times\) MIC (12.5 mg/mL) of FHH affected the shape of the bacterial cells. Cells were more clustered and small buds were formed on the cell wall. The morphology of the cells was changed from a curly to an oval form. A disorganized cytoplasm was also observable. The 2\(\times\) MIC (25 mg/mL) concentration of FHH caused the complete decay of the bacterial cell wall, which led to cell leakage (Figure 1C).