Microbial Succession and Biochemical Interactions During Kombucha Fermentation

Kombucha is a traditional fermented beverage obtained by fermenting sweetened tea using a symbiotic culture of bacteria and yeasts (SCOBY). The present study investigated the microbial succession pattern and major biochemical changes occurring during kombucha fermentation under laboratory conditions. The work focused on identifying dominant microbial groups at different fermentation stages, monitoring physicochemical parameters, and evaluating basic biochemical and antioxidant-related characteristics of the fermented beverage. Kombucha was produced using black tea, sucrose and a starter SCOBY, and fermentation was conducted for 7–14 days at ambient temperature. Microbial isolation was carried out using selective and non-selective culture media, followed by microscopic and staining techniques. Biochemical tests, pH variation, titratable acidity, and qualitative detection of proteins and carbohydrates were performed. The results confirmed the presence of acetic acid bacteria, yeasts and Gram-positive bacteria during fermentation, accompanied by a progressive decline in pH and development of a cellulose pellicle. The study highlights the dynamic microbial interactions responsible for acid production, biofilm formation and biochemical transformations, supporting the potential of kombucha as a functional fermented beverage.