## 3 Results and Discussion
Molds from the species _Epicocum nigrum_ (2.1-8.5%) and genera _Penicillium_ (2.2%) and _Acremonium_ (0.4-0.6%) were isolated with less frequency (Table 2). The presence in parsley leaves of molds from the genera _Cladosporium_, _Aspergillus_, _Penicillium_, _Alternaria_, _Epicocum_, and _Rhizopus_ has been described previously by other authors. The genus _Cladosporium_ is the most often isolated mold. Previous studies have also reported a large variety of fungal genera in parsley compared to other green vegetables intended for direct consumption [38; 53]. Fungi belong to the plant epiphytic microflora. However, their excessive development can both cause spoilage and have health effects for consumers due to the production of mycotoxins that are locally formed and may move inside the plant tissue [54; 55]. There was less diversity of bacteria in the parsley samples than there was diversity of fungi. Five species were identified with the highest isolation frequency: _Pseudomonas fluorescens_; _Klebsiella oxytoca_; _Acinetobacter johnsonii_; _Staphylococcus warneri_; and _Bacillus megaterium_. All isolated bacteria belong to opportunistic pathogens and are common in soil and other natural environments. In their studies of parsley leaves, [38] also identified Enterococcus and rods belonging to _Enterobacteriaceae_. Fungi and spore-forming bacteria are highly resistant to various techniques of disinfection. Due to the storage and use of raw parsley leaves as a food additive, it is important to develop successful methods to eradicate these microorganisms. In the present study, we used ozonated water to rinse the parsley. In the first experiment, we optimized the concentration of ozone in the water and the contact time with the suspension of microorganisms most commonly present in parsley (Figure 2, Table S1). Next, the influence of the organic matter on the effectiveness of ozonation was determined (Figure 3, Table S2). Figure 2: Reduction in number of microorganisms during the ozonation process (1, 3, 5, 10, 15 min) with different ozone concentrations (0.5 O\({}_{3}\) mg and 1.5 O\({}_{3}\) mg/L). The dose of ozone and the type of microorganism had a significant impact on ozonation efficiency, expressed as a reduction in the number of microorganisms isolated from parsley and in mixtures of microorganisms during ozonation under model conditions (Figure 2, Table S1). The ozone dose had the greatest impact on the efficiency of microbial inactivation. Significant statistical differences were noted for most microorganisms in the first minute of the ozonation process. A dose of 1.5 O\({}_{3}\) mg/L resulted in a reduction in microorganisms of more than 0.5 O\({}_{3}\) mg/L. Such a difference was not found for _Bacillus megaterium_ bacteria or for microorganisms, which were completely eliminated during the ozonation process (_Bullera alba_, _Rhodotorula babieva_) (Table S1). Statistically significant differences were found between the first and third minutes of the process at doses of both 0.5 O\({}_{3}\) mg/L and 1.5 O\({}_{3}\) mg/L. After this time, there were no significant statistical differences in the reduction in microorganisms for either dose of ozone. Therefore, it was concluded that the time of the process (1, 3, 5, 10, 15 min) was less important, especially from the fifth minute (Table S1). For most individual microorganisms and their mixtures, a high reduction of \(>\)90% was obtained for a dose of 1.5 O\({}_{3}\) mg/L, with the exception of bacteria _Pseudomonas fluorescens_ (R = 33-48%). Different sensitivity to ozonation was observed among the examined microbial isolates, from the most sensitive to the least sensitive microorganisms as follows: _Bullera alba \(>\) Rhodotorula babievae \(>\) Bacillus megaterium \(>\) Staphylococcus vameri \(>\) Epicocum tigrum \(>\) Cladosporium cladosporoides \(>\) Pseudomonas fluorescens_. The first four microorganisms were almost completely eliminated during ozonation (R \(>\) 95%).