## 3 Results and Discussion
### Biological Activity of Fruit Extracts and lyophilistes
catarralis_, causing more than 50% of inhibition of growth. Quince extract showed an activity higher than 50% of growth inhibition only towards _E. faecalis_, _S. epidermidis_, and _M. luteus_. Comparing the sensitivity of microorganisms, it could be stated that Gram-positive bacteria were more susceptible to fruit extracts. Among the Gram-negative bacteria, _P. aeruginosa_, _S. marcescens_, and _E. coli_ were least sensitive. ity was demonstrated in extracts obtained from chokeberry, sea buckthorn, and hawthorn; however, the inhibition degree was usually below 50% excluding the activity of sea buckthorn towards _L. reuteri_ and chokeberry extract towards _P. pentosacaus_, inhibited in 52 and 62%, respectively. The inhibition degree of red currant, blueberry, and quintec extracts was much lower and did not exceed 30%. It can be noticed that _L. plantarum_ showed the least sensitivity to the extracts. Lyophilistes demonstrated a lower activity towards tested LAB bacteria (Figure 4) with the results not exceeding 40% of growth inhibition. The differences between lyophilistes were not very noticeable; however, differences in the sensitivity of strains were clearly visible. As can be observed, _L. reuteri_ showed the greatest sensitivity, while the least susceptibility was demonstrated by _L. plantarum_. In the presented work, all examined extracts and lyophilistes exhibited antibacterial properties against Gram-positive and Gram-negative bacteria. The inhibition degree strongly depended not only on the fruit type but also the sample preparation as well as the susceptibility of indicator microorganisms. The highest activity towards pathogenic bacteria was demonstrated by chokeberry, sea buckthorn, and red currant extracts; however, hawthorn and blueberry were also active towards the majority of pathogens. In the case of lyophilistes, chokeberry was also the strongest inhibitor; however, blueberry and hawthorn also exhibited a high activity towards pathogenic bacteria. Similar results were reported in the literature. It should be noted that the results described by various authors often indicate very diverse effects due to different methods of sample preparation such as a different extraction method, which usually results in a different composition and concentration of main compounds. [PERSON] et al. [62] examined the antimicrobial effects of powder and hydroalcoholic extracts of berries (rose-hip, aronia, sea buckthorn, and hawthorn) on the growth of antibiotic-resistant _L. monocytogenes_ and observed that the highest bacteriostatic and bactericidal effects were demonstrated in sea buckthorn and rosehip. Aronia and hawthorn did not exhibit antimicrobial activity against _L. monocytogenes_ in their study. The authors explained this by the cumulative effect of the composition of these berries due to the high content of antioxidant compounds and organic acids. [PERSON] et al. [63] conducted research to determine the antioxidant and antimicrobial activities of eight types of berries, including bilberry, black currant, red currant, raspberry, gooseberry, sea buckthorn, sour cherry, and strawberry, harvested from two different geographical regions. The results showed that bilberries and raspberries had the highest antioxidant activity. The extracts from the tested berries demonstrated antibacterial activity against pathogenic bacteria, such as _E. coli_, _B. subtilis_, and _S. aureus_, while the inhibitory effect on _Salmonella_ Typhi and fungi including _Candida albicans_ and _Aspegillus niger_ was absent or very low. The authors underlined that depending on the place of origin, different phytochemical compositions could be observed, which can influence the biological activity. Moreover, the environmental and cultivation conditions in which the berries grow may affect variations in their chemical composition. In contrast to the presented study, the authors observed that the most susceptible indicator microorganism was _E. coli_.