Investigations into the antibiotic activity of tea fungus/kombucha beverage

Abstract

Tea fungus/kombucha, an acetic acid flavoured fermented tea beverage, is widely consumed in various parts of the world and has more recently become a fad in the United States. This is due in part to the fact that it can be produced in the home, and it is reported to be medicinal, effective against arthritis, psoriasis, chronic fatigue, constipation, indigestion and metabolic diseases. Among 264 references from 1852 to 1961, there are reports of.antibiotic activity against Agrobacterium tumefaciens and medicinal value against a variety of diseases. The medicinal value appears to be related to that attributed to vinegar, one of our most ancient foods. We decided to test tea fungus/ kombucha for its antibiotic activity against Helicobacter pylori, a primary cause of gastritis related to peptic ulcers and gastric carcinoma, Escherichia coli, Staphylococcus (Micrococcus) aureus and Agrobacterium tumefaciens. Tea containing 4.36 g of dry tea per litre and 10% of sucrose and fermented with the tea fungus showed no antibiotic activity in the beverage beyond that caused by acetic acid, a primary product of the fermentation.

Antioxidant and Antibacterial Activity of the Beverage Obtained by Fermentation of Sweetened Lemon Balm (Melissa officinalis L.) Tea with Symbiotic Consortium of Bacteria and Yeasts

“…The results of antibacterial activity of kombucha beverages with diff erent TA and control samples confi rm previous suppositions that acetic acid is the dominant active component of kombucha (2,56,57). More acidic beverage had higher inhibition zones (Table 4), which proves that the intensity of the antimicrobial activity of kombucha is directly related to the concentration of acetic acid.…”

“…However, the levels of tea above 4.4 g/L had an off ensive bi er taste and were undrinkable (63). The absence of or an insignifi cant antimicrobial activity of black and green teas at drinkable levels could be explained by the low concentrations of tea and its active components (polyphenols/tannins) (56,59). Also, unfermented winter savory (Satureja montana L.) tea at 5 g/L did not show antimicrobial activity against the tested microorganisms (57).…”

Manufacture of a beverage from cactus pear juice using “tea fungus” fermentation

“…The observed antimicrobial activity was due to the organic acids, primarily acetic acid, and was eliminated when samples were neutralized. Many studies on kombucha have proven that its antimicrobial activity against pathogenic microorganisms is largely attributable to acetic acid (Steinkraus et al 1996), which is a known antimicrobial agent (Sreeramulu et al 2000). Adams (1985) demonstrated that pathogenic and spore-forming bacteria were inhibited at as little as 1 g/l of acetic acid.…”

Determination and Characterization of the Antimicrobial Activity of the Fermented TeaKombucha

“…Numerous popular media features in the U.S.A. have highlighted the beverage and its uses, including the New York Times and Miami Herald, suggesting that Kombucha consumption can reduce blood pressure, relieve arthritis, increase the immune response, and cure cancer (2,3). Kombucha lends itself to expansive consumption as a healthful beverage as it is easily and safely produced at home (4). Production of the tea is achieved by infusing tea leaves in freshly boiled water and sweetening it with about 100 g/L sucrose or honey.…”