## 3 Results
### Antagonistic Activity of Lactic Acid Bacteria
The lowest antagonistic activity (zone of growth inhibition in the range of 16-20 mm) was recorded for the system consisting of the _Levilactobacillus brevis_ MG451814 culture and polyphenols contained in extracts from the _Rosa rugosa_ Thunb. pseudo-fruit pomace. Low antimicrobial potential (growth inhibition zone: 17-19 mm) was also observed in the systems consisting of _Levilactobacillus brevis_ LOCK 0980 cultures and cleaned crude ethanolic and acetone extracts, as well as for the system based on the culture of the _Lacticaseibacillus casei_ LOCK 0979 strain and purified acetone extract (growth inhibition zone equal to 19.67 mm). It is worth mentioning that the addition of extracts to the culture of lactic acid bacteria would significantly affect their anti-staphylococcal properties in relation to the _S. saprophyticus_ R3A strain (in 18/28 cases, the 2-component LR system showed statistically significantly lower anti-staphylococcal properties than the basic culture) (Figure 2 and Table A2, Appendix A). In the case of the _S. saprophyticus_ S1A strain, the highest antagonistic activity was recorded in the LR system consisting of _Levilactobacillus brevis_ LOCK 0992 and polyphenols contained in the crude acetone extract (zone of growth inhibition equal to 36 mm) (Figure 1g). On the other hand, the system consisting of purified ethanol extract and the _Levilactobacillus brevis_ MG4511814 strain was characterized by the lowest anti-staphylococcal activity (Figure 1h). In the case of the purified acetone extracts, it was not possible to clearly indicate which environmental system showed the greatest antimicrobial potential in relation to the _S. saprophyticus_ S1A strain (combination of purified acetone extract with the _Levilactobacillus brevis_ LOCK 0992 strain, with a growth inhibition zone equal to 27.67 mm, and the combination of purified acetone extract and the _Lactobacillus acidophilus_ LOCK 0928 strain, with a growth inhibition zone equal to 28.33 mm). In the case of ethanol extracts, the highest anti-staphylococcal activity was obtained by combining them with the _Levilactobacillus brevis_ LOCK 0992 strain (zone of growth inhibition equal to 30.33 mm). The system based on the culture of _Lactobacillus acidophilus_ LOCK 0928 bacteria and crude ethanol extract (zone of growth inhibition equal to 27.33 mm) also showed a high antimicrobial potential. The weakest anti-staphylococcal properties in relation to _S. saprophyticus_ S1A were demonstrated by the combination of acetone extracts with the _Levilactobacillus brevis_ LOCK 0980 strain and ethanol extracts with the _Levilactobacillus brevis_ MG451814 strain (zones of growth inhibition equal to 15-17 mm). It should be noted that the antimicrobial activity of the 28 LR systems against the _S. saprophyticus_ S1A strain was largely due to the antagonistic activity of the LAB strains used to create the system. In all cases (28/28), the addition of the extract resulted in a statistically significant reduction in anti-staphylococcal properties compared with the stock culture (Figure 2). The _S. aureus_ S2A strain, compared with the other environmental isolates, was the most resistant to the effects of the two-component LR systems (Figure 1i,j). This was evidenced by the fact that the highest zone of inhibition of growth (not exceeding 20 mm) was comparable to the value of the minimum zones of inhibition of growth of other staphylococci. In the case of the _S. aureus_ S2A strain, an anti-staphylococcal potential was observed in the systems consisting of the culture of _Levilactobacillus brevis_ LOCK 0992 with acetone extracts (zone of growth inhibition of about 19 mm) and the culture of _Levilactobacillus brevis_ MG451814 with the addition of ethanol extracts (zone of growth inhibition in the interval 17-20 mm). A moderate anti-staphylococcal potential in relation to the _S.