It has long been reported that a natural constituent of Kombucha is ‘glucuronic acid’, to which researchers attributed much of the beneficial effects of the beverage (which I tended to attribute to Camellia sinensis tea in which it is brewed). More recently, Michael Roussin [], claiming personal exhaustive analysis of hundreds of specimens has disputed the presence of glucuronic acid in Kombucha and the heretofore popular notion of glucuronic acid conjugation of toxins and suggested that in the apparent absence of glucuronic acid, another candidate, ‘Saccharic acid 1,4-lactone’, might be responsible for the beneficial effects usually attributed to glucuronic acid. This dispute is far from final and much work still needs to be done.

My position (Stuart Thomson) [] is that whilst I welcome debate in pursuit of knowledge on the subject, I shall continue to report the presence of glucuronic acid as a constituent of Kombucha as long as respectable researchers continue to report its presence in Kombucha in peer-reviewed journals, or until they alter their position in the light of any possible future evidence to the contrary, which is the practice of science (in the absence of vested financial interests to resist accurate reporting or revision of the known facts and which latter scenario does not appear to prevail here, where early correction of error remains the only sensible course to preserve one’s professional reputation and ego).

As can be discerned from my collated summary abstracts below, Roussin’s position, although widely blindly reported, does not currently hold up against continuing reports to the contrary. In particular, Eastern Block and allied researchers appear to be grouping and reiterating their position that glucuronic acid is indeed an active beneficial constituent of Kombucha, which holds great promise for socialist and developing countries where far less financial resources are available to treat e.g. increasingly drug-resistant infectious diseases such as DR & XDR strains of Tuberculosis, which are less common and less developmentally lucrative propositions in better resourced, developed countries (Personal Communication, May 2007, with Dr Anita Segal, Microbiological Chief, Cantacuzino Institute, Bucharest Romania, from 1952 –1956, whilst personally confirming the acidic therapeutic properties produced by Kombucha metabolic activity).


Researchers at the ‘Department of Biochemical Engineering and Food, National Institute of Applied Sciences, Toulouse, France’, using high-performance liquid chromatography (ION 300 Interaction Column, H2SO4 0.5mm as mobile phase, room temp, UV detection) determined that when Kombucha tea fungus culture micro-organisms were cultured in their traditional medium, several metabolites were identified and quantified: lactic, acetic and gluconic acids and at low levels, glucuronic acid (<10mg/l).

(Blanc P, ‘Characterization of the tea fungus metabolites’, Biotechnol Lett, 18(2), 1996)

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Researchers at the ‘Department of Applied Chemistry, Faculty of Technology, University of Novi Sad, Yugoslavia’ studied the influence of concentrations of sucrose in a Kombucha tea fungus culture, which produced glucuronic acid beside some other organic acids. The content of glucuronic acid continuously increased and maximum production was reached after 7-days of fermentation (0.0175mmol/L) on a sucrose concentration of 0.2931M.

(Loncar E et al, ‘Biosynthesis of glucuronic acid by means of tea fungus’, Nahrung 44(2), 2000)

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Researchers at the ‘Department of Applied Chemistry, Faculty of Technology, University of Novi Sad, Yugoslavia’, cited earlier authorative published analysis proving positive for glucuronic acid in Kombucha tea fungus cultures as:

L.T. DANIELOVA, Trudy Erevanskogo zooveterinarnogo Instituta, 17, 201­216 (1954);
L. N. KONOVALOV, M. .N. SEMENOVA, Bot. Žurnal (Moskva), 40(4), 567­570 (1955);
P. H. LIST, W. HUFSCHMIDT, Pharm. Zentralhalle, 98(11), 593­598 (1959);
S. PETROVIC, E. LONCAR, Mikrobiologija, 33(2), 101­106 (1996);
J. REISS, Dtsch. Lebensm.­Rundsch., 83, 286­290 (1987);
E. S. LONCAR, S. E. PETROVIC, R. V. MALBAŠA, R. M. VERAC, Nahrung 44, 138­139 (2000).

(Malbaša R et al, ‘Sucrose and Inulin Balance During Tea Fungus Fermentation’, Roum Biotechnol Lett, 7(1), 2002)

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Researchers at the ‘Department of Biotechnology and Pharmaceutical Engineering, University of Novi Sad, Yugoslavia’, reported that in addition to tea components and sugar, Kombucha tea fungus culture contains acetic acid, gluconic acids, L-lactic acids and vitamin C and quoting the above work of Loncar and others, opined that one of the most important metabolites from therapeutic point of view is glucuronic acid, a carrier of detoxification activity of Kombucha.

(Cvetkovic D, Markov S, ‘Cultivation of Tea Fungus on Malt Extract Medium’, Acta Periodica Tech, 33: 117, 2002)

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Researchers at the ‘Department of Analytical Chemistry, School of Biochemistry and Biological Sciences, University of Ciudad, Santa Fe, Argentina’, reported quite definitively, using progressive modern analytical techniques, as follows:

An experiment was developed as a simple alternative to existing analytical methods for the quantitation of glucuronic acid (main product) in the bioprocesses of Kombucha tea fungus culture by using Fourier transform infrared (FTIR) spectroscopy coupled to multivariate calibration (partial least-squares, PLS-1 and artificial neural networks, ANNs). Wavelength selection through a novel ranked regions genetic algorithm (RRGA) was used to enhance the predictive ability of the chemometric models. Acceptable results were obtained by using the ANNs models considering the complexity of the sample and the speediness and simplicity of the method. The accuracy on the glucuronic acid determination was calculated by analysing spiked real fermentation samples (recoveries ca. 115%).”

(Franco V et al, ‘Monitoring substrate and products in a bioprocess with FTIR spectroscopy coupled to artificial neural networks enhanced with a genetic-algorithm-based method for wavelength selection’, Tatlana - Intl J Pure App Analyt Chem, 68(3), 2006)

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Researchers at the ‘Oncology Institute of Vojvodina and Department of Biotechnology and Pharmaceutical Engineering, Faculty of Technology, University of Novi Sad, Serbia’ have recently reiterated their opinion that the beneficial effects of Kombucha are attributed to the presence of (amongst other things) glucuronic acid produced during fermentation.

(Mrdanovic J et al, ‘The frequency of sister chromatid exchange and micronuclei in evaluation of cytogenetic activity of Kombucha on human peripheral blood lymphocytes’, Arch Oncol, 15(3-4), 2007)

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Researchers at the ‘Microbial Biotechnology Division, Department of Biotechnology, University of Bharathiar, India’, studied changes in content of organic acid in Kombucha tea fungus culture utilising high-performance liquid chromatography and determined that the glucuronic acid concentration reached a maximum up to 2.3 g/l in on the 12th day of fermentation.

(Jayabalan R et al, ‘Changes in content of organic acids and tea polyphenols during Kombucha fermentation’, Food Chem, 102(1), 2007)

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A researcher/lecturer in the Food Technology Faculty, Slamet Riyadi University, Surakarta, Indonesia, reasoning that because the functional properties of Kombucha correlate tightly with its glucuronic acid content, undertook research aimed at studying the dominating microbes, growth pattern and optimised process to develop Kombucha with the highest possible content of glucuronic acid, comparing cane, coconut and arenga sugars. Results showed that although cane sugar yielded the highest microbial growth, a better carbon source for the highest formation of metabolites was coconut and arenga sugars. It was determined that with Kombucha, the higher the concentration of sugar (10%) and fermentation temperature (30°C), the greater was the degree of sediment and the yield of glucuronic acid.

(Karyantina M, 'Optimalization Process Kombucha With Variation Degrees Of Coconut Sugar', Mercuria, 12 November, 2008)

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Researchers at ‘The Microbial Biotechnology Division, Department of Biotechnology, Bharathiar University and the Department of Biotechnology, Bannari Amman Institute of Technology, Tamil Nadu, India’, and associate researchers at ‘The Division of Biotechnology, Department of Food Science and Technology, Chonbuk National University, Jeonju, Republic of Korea’, have most recently published their results of gas chromatographic analysis of Kombucha tea fungus culture, which determined glucuronic acid at 0.38g/100ml, which result they stated were “in agreement with the results of Blanc and Jayabalan et al”. [(Blanc P, Biotechnol Lett, 18(2), 1996); (Jayabalan R et al, Food Chem, 102(1), 2007)]

Technical Details of the Gas Chromatographic Analysis of Kombucha Tea
A 2-ml fraction of kombucha tea was injected into a Hitatchi G-3000 gas chromatography equipped with a flame ionization detector. A stainless steel column (2 m×2 mm) packed with Porapack Q was used for separation. The column, injector, and detector temperatures were 80, 40, and 120°C, respectively. Nitrogen gas was used as the carrier gas at a flow rate of 15ml/min.

Detailed Results of the Gas Chromatographic Analysis of Kombucha Tea
Black tea fermented with tea fungus for 14 days contains acetic acid of 1.60g/100 ml; succinic acid, 0.65g/100 ml; gluconic acid, 0.20g/100ml and glucuronic acid, 0.38g/100ml.

(Murugesan G et al, ‘Hepatoprotective and Curative Properties of Kombucha Tea Against Carbon Tetrachloride-Induced Toxicity’, J Microbiol Biotechnol 19(0nline 30 Jan 09), 2009)

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In closing, let me shake up this whole matter with a curved ball.

Researchers at the ‘Faculty of Science, Fernando Pessoa University’ and the ‘Faculty of Pharmacognosy and Pharmacy at do Porto University’, Portugal, add more intrigue to the debate, claiming: “As far as we know, few chemical studies concerning leaves’ organic acid profiles have been developed. Before’ Kombucha tea fermentation (green and black tea leaves), the main organic acid is D-glucuronic acid. Nevertheless, acetic, lactic and citric acids are also found after fermentation and their contents are significant changed during fermentation time (Jayabalan et al, 2007).

(Oliveira A et al, Food Chem, 111(2), 2008)

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Does this serve to return me full circle to my original contention that much of the beneficial effects of the Kombucha beverage are attributable to the Camellia sinensis tea with which it is brewed?



[Please feel free to contact the author of this page ( regarding any errors and or additions you may consider relevant to the raised aspects of this ongoing debate]



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