The project has already generated important preliminary scientific results:
1. Successful EV Isolation: Different populations of EVs were successfully isolated from three different commercial sources of kombucha using both primary and secondary fermentations. These nanoparticles were visualized by cryoTEM and ILM, representing one of the first systematic analyses of EVs in a food fermentation context.
Genome sequencing identified the dominant bacterial and yeast strains: The Komagataeibacter rhaeticus (<20%), a cellulose-producing bacteria and Brettanomyces bruxellensis (>60%), an osmophilic yeast strains were identified as dominant strains in the kombucha model systems (both first and second fermentations). Whereas >60% of K. rhaeticus and <10% of B. bruxellensis considered as dominant strains in the SCOBY pellicles.
2. EVs were found to vary in concentration and size distribution across different kombucha and SCOBY samples, suggesting that microbial composition influences EVs production.
3. Protein Diversity: SDS-PAGE profiling revealed that kombucha EVs contain diverse proteins, potentially linked to microbial adaptation, metabolism, and symbiosis.
4. Scientific and technological impact
This research has yielded foundational insights into microbial ecology and the biology of EVs, advancing our understanding of microbial interactions within complex ecosystems such as the microbial community of kombucha. Using fluorescent labelling and advanced microscopy, the study showed that EVs are actively exchanged between bacteria and yeast, supporting their role in cross-kingdom microbial communication. These findings underscore the significance of EVs as mediators of biochemical exchange and signaling across diverse microbial taxa.
Biotechnological Applications: The discovery of functional EVs in kombucha cultures opens promising avenues for biotechnological innovation. These vesicles may be harnessed for the development of functional foods with enhanced health benefits, natural antimicrobial agents, or novel biomaterials with unique properties derived from microbial sources.
Biomedical Relevance: By elucidating the mechanisms of microbial EV production and uptake, the research contributes to a deeper understanding of microbiome–host interactions and the potential of EVs as vehicles for therapeutic delivery. This knowledge may inform future strategies in precision medicine, including microbiome modulation and targeted drug delivery systems.
By the end of the project, SCOBY-DO is expected to deliver the first comprehensive framework of EV-mediated microbial communication in a natural symbiotic consortium. Further studies will include the exploitation of kombucha EVS in precision nutrition and their potential prebiotic activities.
