Enhanced Probiotic Stability and Functional Beverage Potential through Bacterial Cellulose Encapsulation of Saccharomyces boulardii

Bacterial cellulose (BC), synthesized by acetic acid bacteria, provides a versatile biofilm with promising potential for probiotic delivery. This study investigates the encapsulation of the probiotic yeast Saccharomyces boulardii within BC to improve its resilience against harsh digestive conditions. By co-culturing Komagataeibacter rhaeticus JYCB292, a BC-producing bacterium, with S. boulardii, we developed BC beads that encapsulate the yeast, forming a structure similar to coconut jelly. To demonstrate the protection provided by bacterial cellulose encapsulation, we used YFP-labelled S. cerevisiae W303, a species closely related to S. boulardii. The results showed that encapsulated yeast retained fluorescence, indicating high survival rates after exposure to simulated digestion and cold storage, while non-encapsulated yeast lost fluorescence. This highlights the potential protective capability of bacterial cellulose for S. boulardii. Scanning electron microscopy further confirmed the successful encapsulation of S. boulardii within bacterial cellulose. Additionally, coculturing in a tea medium at 28°C for one week produced a fermented beverage with polyphenol (0.05 ± 0.01 gallic acid mg/mL) and flavonoid content (0.13 ± 0.03 quercetin mg/mL), as well as antioxidant activity (0.06 ± 0.005 FeSO4 mg/mL in FRAP analysis, and 88.56 ± 1.42 % in DPPH scavenging assay), comparable to that of tea fermented by commercial kombucha starters. This encapsulation technique not only enhances probiotic stability in the digestive tract but also provides a novel approach to creating functional beverages with potential health benefits. These findings suggest that BC-encapsulated probiotics in a tea-based medium could serve as a stable, health-promoting alternative to traditional kombucha products.