*2.2. Antibacterial Activity*

The results of the antibacterial activity assay showed that the positive control (Tetracycline 1.6 mg/mL) demonstrated the highest inhibition against all tested phytopathogenic bacteria (Table 2). However, peppermint EO showed the highest significant antibacterial activity against *P. syringae* pv. *phaseolicola* (the diameter of inhibition zone was 39.5 mm) similar to tetracycline (1.6 mg/mL) where the diameter of its inhibition zone was 40 mm. In addition, there was a moderate activity against *C. michiganensis* at 10 mg/mL and low activity against *P. savastanoi* only at 10 mg/mL. On the other hand, there was no activity against *X. campestris*.


**Table 2.** Antibacterial activity of *Mentha* × *piperita* cv. 'Kristinka' EO.

Values followed by different letters for each tested bacterium in each column are significantly different at *p* < 0.05 according to two-way ANOVA combined with Duncan post hoc test. Data are expressed as the mean of three replicates ± SD.
