Determination and characterization of the antimicrobial activity of the fermented tea Kombucha

Early reports on Kombucha, a traditional fermented ten beverage, suggested :that it has antimicrobial activity against a spectrum of organisms, and that concentrates of unfermented ten components also have anti microbial properties. Therefore, the focus of this study was to determine and characterize Kombucha's antimicrobial activity using an absorbent disc method. Antimicrobial activity was observed in the fermented samples containing 33 g/L total acid (7 g/L acetic acid) against the tested cram-positive and cram-negative organisms (Agrobacterium tumefaciens, Bacillus cereus, Salmonella choleraesuis serotype typhimurium, Staphylococcus aureus, and Escherichia coli. Candida albicans was not inhibited by Kombucha. The contribution of tea itself to the antimicrobial activity of Kombucha proved to be significant in the tested organisms, even at the highest levels tested 70 g/L dry ten. As a result, the antimicrobial activity of Kombucha was attributed to its acetic acid content.