Honeydew Honey as a Reservoir of Bacteria with Antibacterial and Probiotic Properties

The purpose of this study was to isolate, identify, and evaluate the antibacterial and probiotic potential of bacteria from honeydew honey collected in Poland. Isolates (189 colonies from 10 honey samples) were evaluated for their antimicrobial activity against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Yersinia enterocolitica, and then identified by MALDI-TOF-MS. The isolates with the greatest antimicrobial properties were screened for their probiotic potential. The total number of bacteria isolated from honey did not exceed the value of 2.5 × 10² CFU/mL. The Bacillus pumilus/altitudinis, B. licheniformis, and Bacillus cereus groups were the dominant identified bacteria. Almost 16% of the isolates expressed antibacterial potential against three pathogenic bacteria, over 20% against two, while almost 34% of the isolates did not inhibit any. The survival rate of the isolates under gastrointestinal tract conditions was higher after 4 h of exposure to bile salts (>60% survival rate for 66.66% of the isolates), while at pH 2.0, it was lower (>50% survival rate for 44% of the isolates). The most resistant isolate B. pumilus/altitudinis survived at a rate of 77% at low pH and 108% with bile salts. These results confirmed that honeydew honey is a promising reservoir of bacteria that produces metabolites with antimicrobial and probiotic potential.