Evaluation of antibacterial activity of black and green tea kombucha

Abstract

Currently, the search for natural antimicrobial agents has increased. Thereat, plant extracts, products of fermentative processes, and microbial growth have been tested. Kombucha is a fermented beverage that resulted from the fermentation of the infusion of Camellia sinensis. There are reports about biological activities, such as anti-inflammatory, digestibility, antioxidant, antimicrobial, and others. The study aimed to evaluate the antibacterial activity of black and green tea kombucha against eight foodborne pathogenic microorganisms. The antibacterial activity was analyzed using the agar well diffusion method. Each kombucha consisted of three treatments: natural, neutralized, and filtered. The solutions of acetic acid (4% v.v^-1) and kanamycin (30 µg.L^-1) were used as a control. The black and green tea kombucha beverages, not neutralized, showed antibacterial activity against Escherichia coli serotypes. Black and green tea kombucha did not show antibacterial activity against Staphylococcus aureus, Shigella Flexneri, and Salmonella Typhimurium. The inhibition may be attributed to acetic acid production during the fermentation process. Therefore, it appears that kombucha may have a potential antimicrobial agent.

Keywords: Camellia sinensis, fermentation, antimicrobial.