Antimicrobial Activity of European Plum Fruits (Prunus domestica L.) Depending on Altitude

The research aimed to establish the antimicrobial activity of plum fruits in inhibiting the
development of selected bacteria and fungi strains. Eight plum cultivars (‘^a~anska Rana’, ‘^a~anska Lepotica’, ‘Timo~anka’, ‘^a~anska Najbolja’, ‘Mildora’, ‘Krina’, ‘^a~anska Rodna’, and ‘Stanley’) from two different growing locations (300 and 550 m altitudes) were included in the study. Antimicrobial activity of the plum extract was determined using the microdilution method (minimum inhibitory concentration ‡ MIC). The antimicrobial activity significantly varied among the tested cultivars and altitudes. The cultivars showed different antibacterial activity, with MIC values ranging from
21.97 to 195.31 μg ml-1 and antifungal activity ranging from 21.97 to 63.49 μg ml-1. Depending on
the altitude, antibacterial activity in the plum fruits ranged from 19.53 to 260.41 μg ml-1, and antifungal activity varied from 19.53 to 97.67 μg ml-1. In general, plum fruits showed the highest activity
against Escherichia coli and Aspergillus niger. The obtained results suggested that plum fruits have
significant antimicrobial activity, which can contribute to the global acceptance of plums as a functional food.