Molecular Identification and Antibiofilm Potential of Bacteria Isolated from Vanilla planifolia Beans

Abstract

The bacterial profile associated with Vanilla planifolia beans plays an important role in fermentation processes and the production of bioactive compounds, yet its potential as a source of antibiofilm agents remains poorly understood. This study aimed to isolate bacteria from fermented and dried (unfermented) V. planifolia beans using different pH isolation media, characterize their bacterial profiles through molecular identification, and evaluate their antibiofilm potential against two clinically relevant biofilm-forming pathogens. Bacterial strains were isolated on MRS agar adjusted to pH 4 and pH 7, followed by morphological and Gram-staining characterization. Molecular identification was performed using 16S rRNA gene sequencing and BLAST analysis. Antibiofilm activity was assessed using a microtiter plate assay against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. A total of 38 bacterial isolates were obtained, with fermented vanilla beans yielding more isolates (23 isolates) than dried (unfermented) vanilla beans (15 isolates). The bacterial profile was dominated by members of the genera Bacillus, Staphylococcus, and Liquorilactobacillus. Eight isolates exhibited strong antibiofilm activity, with biofilm inhibition reaching 89.9% against S. aureus and 99.6% against E. coli. Notably, the detection of Liquorilactobacillus hordei in fermented vanilla beans expands the known ecological distribution of this genus beyond conventional fermented beverages. These findings demonstrate that bacteria associated with fermented and dried/unfermented V. planifolia beans represent promising sources of antibiofilm compounds with potential applications in food safety, healthcare, and biotechnology as sustainable alternatives to conventional antimicrobial agents.