Microbiological characterization and antimicrobial activity of honey produced by Melipona scutellaris (uruçu bee) from the Brazilian Northeast

Aim: This study aimed to evaluate the physicochemical characteristics, microbial density, and antimicrobial activity of honey produced by Melipona scutellaris, a stingless bee known as uruçu bee, in Northeastern Brazil. Methods: Physicochemical analyses of honey included moisture, pH, titratable acidity, and organoleptic characteristics. Microbiological quality was evaluated using selective media for bacteria, yeasts, molds, and endospore-forming bacteria. Antimicrobial activity of honey samples was assessed by agar well diffusion against standard bacterial strains, measuring inhibition zone diameters. Results: The honey samples showed the moisture content from 25.3% to 38.6%, pH from 3.3 to 5.4, and titratable acidity from 0.6% to 2.8% v/w. The honey samples showed wide variation in microbial counts. Total bacterial counts ranged from 1.20 × 10⁴ to 1.15 × 10⁷ CFU/g. Spore-forming bacteria averaged 3.54 × 10² CFU/g, while yeast counts ranged from 1.00 × 103 to 5.00 × 10⁶ CFU/g, and filamentous fungi from 3.00 × 102 to 18.98 × 10⁵ CFU/g. Among bacterial isolates obtained from honey the most were Gram positive endospore-forming rods (53%) and Streptomyces spp. (42%). All honey samples inhibited the growth of B. cereus, E. coli, and S. aureus, with consistently strong activity observed against S. aureus. In contrast, the inhibitory effects on E. coli and B. cereus varied across samples. Only four of seven samples inhibited P. aeruginosa, and none showed activity against C. albicans. Conclusion: The findings of this study contribute to a better understanding of microbiological quality of honey and its therapeutic potential, supporting its traditional medicine use.