Antimicrobial effect of Kombucha analogues

Kombucha is a traditional refreshing beverage obtained by the fermentation of sugared tea with a powerful symbiosis of acetic bacteria and yeasts. This drink has been intensively consumed during a long time worldwide for its prophylactic and therapeutic properties. In the present study, we have screened traditional fermented black tea for antibacterial and antifungal activity against Gram (+) and Gram (-) human pathogenic bacteria (n = 7) and candida yeasts (n = 7) using agar diffusion method. Additionally, antimicrobial activity of five new fermented beverages produced from the following medicinal herbal extracts: Thymus vulgaris L. Lippia citriodora, Rosmarinus officinalis, Foeniculum vulgare and Mentha piperita noted as Kombucha-analogues were investigated, using agar diffusion method. Strong antimicrobial potentials were found with the new fermented beverages, particularly those prepared by the fermentation of L citriodora and F. vulgare infusions, exhibiting the most important inhibition zone observed against the Candida strains tested (Candida glabrata, Candida tropicalis, Candida sake, Candida dubliniensis and Candida albicans). In view of their antimicrobial activity demonstrated against a range of pathogenic bacteria and against a number of clinical Candida species, the fermented L citriodora and F. vulgare may be very healthful. (C) 2012 Elsevier Ltd. All rights reserved.