ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF BLACK AND GREEN KOMBUCHA TEAS

ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF BLACK ANDGREEN KOMBUCHA TEASjfbc_629 1..6

HOUDA BATTIKH1,2, KAMEL CHAIEB2, AMINA BAKHROUF2 and EMNA AMMAR1,3

1UR Étude et Gestion des Environnements Urbains et Côtiers, Université de Sfax, LARSEN, École Nationale d’Ingénieurs de Sfax, BP 1173-3038 Sfax,Tunisia2Laboratoire d’Analyse, Traitement et Valorisation des Polluants de l’Environnement et des Produits, Faculté de Pharmacie, rue Avicenne, 5000Monastir, Tunisia

3Corresponding author. TEL:+216-98-41-23-64; FAX: +216-74-27-55-95;EMAIL: [email protected]

Accepted for Publication June 20, 2011

doi:10.1111/j.1745-4514.2011.00629.x

ABSTRACT

Kombucha is widely consumed as black tea fermented for 7–14 days. The aim of thepresent study was to compare the antimicrobial activities of two kombucha bever-ages originating from green and black teas fermented for 21 days and to characterizethe antimicrobial compounds (heat resistance and pH stability). Green and black teainfusions were fermented with a traditional kombucha culture. The resulting kom-bucha antibacterial/antifungal activities against some pathogenic microorganisms,including human pathogenic bacteria and clinical Candida species, were investi-gated using the agar diffusion method. The results showed interesting antimicrobialpotentials of both experimented kombucha teas against the tested microorganisms,except Candida krusei. The green fermented tea exhibited the highest antimicrobialpotential. Indeed, it showed large inhibition zones against Staphylococcus epidermi-dis (22 mm), Listeria monocytogenes (22 mm) and Micrococcus luteus (21.5 mm).Furthermore, interesting anti-Candida potential was revealed by the reaction ofgreen tea kombucha against Candida parapsilosis.

PRACTICAL APPLICATIONS

The black fermented tea is the original and most popular preparation. This researchhas focused on the investigation of the antibacterial and antifungal activities of thekombucha prepared from green and black teas against a large number of humanpathogens to determine and to compare the potential of the two kombucha drinks.The results showed a broad antimicrobial spectrum of kombucha against a range ofpathogenic Candida involved in several candidoses. Moreover, the data showed thatthe antibacterial potential of kombucha prepared from green tea was higher than thatof the original kombucha tea. Considering the antimicrobial activity demonstratedagainst a wide range of pathogenic bacteria and clinical Candida species, kombuchamay be very healthful. As resistance to antimicrobial agents has become increasinglyan important global health problem, these findings would be very promising andcould be useful as an alternative to current synthetic antimicrobial drugs.

INTRODUCTION

Kombucha is a traditional refreshing beverage resulting fromthe fermentation of sugared tea with a symbiosis culture ofacetic bacteria (Acetobacter xylinum, Acetobacter xylinoides orBacterium gluconicum) and yeasts (Saccharomyces cerevisiae,Zygosaccharomyces bailii, Schizosaccharomyces pombe, Saccha-

romyces ludwigii, Zygosaccharomyces rouxii, Torulaspora del-brueckii, Brettanomyces bruxellensis, Brettanomyces lambicus,Brettanomyces custersii, Candida sp. or Pichia membranaefa-ciens) (Jankovic and Stojanovic 1994; Mayser et al. 1995;Blanc 1996; Liu et al. 1996; Balentine 1997; Chen and Liu2000; Teoh et al. 2004). Kombucha fermentation is generallyinitiated by osmotolerant species, succeeded and ultimately

Journal of Food Biochemistry ISSN 1745-4514

1Journal of Food Biochemistry •• (2012) ••–•• © 2012 Wiley Periodicals, Inc.

dominated by acetic tolerant species (Teoh et al. 2004). It ischaracterized by A. xylinum activity, producing a floating cel-lulose pellicle, where cells have been embedded to benefitfrom close contact with the atmospheric oxygen (Malbašaet al. 2008). The tea fungus broth is composed of two phases: asolid floating cellulosic pellicle layer and a sour liquid phase.Acetic acid, ethanol and gluconic acid are the major compo-nents of the liquid phase. Other minor constituents such aslactic acid, glucuronic acid, phenolic acids, vitamin B groupand enzymes are also present.

By virtue of the numerous reported health-promotingvirtues and straightforward safe preparation, this beveragehas gained widespread popularity. Indeed, kombucha hasbeen intensively consumed worldwide for a very long time,thanks to its prophylactic and therapeutic properties (Frank1995; Greenwalt et al. 1998, 2000; Dufresne and Farnworth2000; Yang et al. 2009). Particularly, many scientific reportsproved that the beverage exerts antimicrobial activity againsta broad range of bacteria (Greenwalt et al. 1998, 2000; Sreera-mulu et al. 2001). Furthermore, bacteria and fungi that arepresent in kombucha form a powerful symbiosis and are ableto inhibit the growth of potential contaminating bacteria(Liu et al. 1996; Balentine 1997). Indeed, the black tea drinkfermented for 14 days was proved to be able to inhibit thegrowth of Shigella sonnei, Escherichia coli, Salmonella enteriti-dis and Salmonella typhimurium (Sreeramulu et al. 2001).Steinkraus et al. (1996) reported the antibiotic activity ofkombucha against Helicobacter pylori, E. coli, Staphylococcusaureus and Agrobacterium tumefaciens mainly related to theacetic acid produced during the fermentation process. Green-walt et al. (1998) reported the antimicrobial potentials ofkombucha from both black and green teas on the ninth dayof fermentation against S. aureus, E. coli serotype H10 (non-pathogenic), E. coli serotype H48 (pathogenic), S. typhimu-rium, Bacillus cereus and A. tumefaciens. They also suggested asimilar reaction of these two types of fermented teas withoutfinding any activity against Candida albicans. The analyses ofthe fermented liquid revealed the presence of acetic, lactic andgluconic acids as the major chemical compounds (Frank1995; Hobbs 1995). Tietze (1995) described the presence ofusnic acid, which is an antibacterial agent, in kombucha cul-tures. More recently, acetic acid has been suggested to be themajor antimicrobial agent (Greenwalt et al. 1998), and othercompounds such as bacteriocins and tea-derived phenoliccompounds may also be involved (Sreeramulu et al. 2001).Systematic investigation of the antimicrobial activity of kom-bucha revealed the presence of antimicrobial compoundsother than organic acids or proteins (enzymes) producedduring fermentation as well as tannins originally present inthe tea broth (Sreeramulu et al. 2001).

Although green tea can be used for the preparation of kom-bucha, most of the studies on the antimicrobial activity ofdrinks were carried out on kombucha prepared from black

tea, known as the best substrate (Reiss 1994; Jayabalan et al.2007). Considering the botanical aspect, tea plants belong tothe Theaceae family comprising two main varieties: Camelliasinensis var. sinensis and Camellia sinensis var. assamica (Haraet al. 1995a). The first apical leaves are picked from the ever-green shrub and can be processed by different methods.Green tea is readily dried with or without a fixation step toinactivate enzymes (Hara et al. 1995b), while black tea, themost popular form around the world, is the result of the oxi-dation of leaf polyphenols through a multistage enzymaticprocess fermentation (Hara et al. 1995c). Hence, the compo-sition differences between the two types of teas lead to differ-ent fermented beverages. Indeed, tea is a very rich complex ofover 2,000 different substances (Wheeler and Wheeler 2004).Moreover, the fermentation process contribution leads toseveral modifications of the final drink composition withbiotransformation, secretion and/or degradation of manycomponents. Thus, the resulting kombucha metabolic com-position is related to the original substrate in addition to thefermentation duration, ranging from 7 to 10 days at roomtemperature (Chen and Liu 2000). These parameters need tobe considered with more quantitative investigations in orderto determine the active compounds and predict the consistentquality of the drink.

The aim of the present study was to evaluate the antifungaland antibacterial activities of kombucha prepared from greenand black teas (fermented for 21 days) in order to compare therelative quality of the two fermented beverages. In addition,the characterizations of the heat resistance and pH stability ofthe antimicrobial compounds were also investigated.

MATERIALS AND METHODS

Starter Culture

The tea fungus used in this study was a Japanese traditionalculture kindly provided by Mr. lan Ogino, an expert of JapanInternational Cooperation Agency. The starter used was asymbiotic culture between yeast and acetic bacteria, mainlyA. xylinum.

Preparation of Fermented Tea

Kombucha drinks were prepared using black and green teas(Les jardins du thé, Office Tunisien du Commerce, Tunis,Tunisia). The infusions were prepared after mixing the tealeaves at 10% (w/v) with 20% of sucrose (w/v) in boilingwater and steeped for 15 min. The infusions were then filteredusing filter paper. The resulting clear filtrate was poured into250-mL Erlenmeyer flasks. After being cooled to room tem-perature, the flasks were inoculated with actively growingkombucha culture composed of two portions: a floating cel-lulose pellicle layer and the liquid broth containing the main

ANTIMICROBIAL ACTIVITIES OF FERMENTED TEAS H. BATTIKH ET AL.

2 Journal of Food Biochemistry •• (2012) ••–•• © 2012 Wiley Periodicals, Inc.

microorganisms involved in the fermentation process. Theflasks were covered and incubated at room temperature. After21 days, the fermented broths were centrifuged at 4,000 rpm,and the supernatants were used for analysis. Unfermented(uninoculated) broths were prepared simultaneously asdescribed earlier, and centrifuged supernatants were used ascontrols.

pH Determination

The pH of the fermented teas and extracts were measuredwith an electronic pH meter (Inolab Level 1, WTW Weilheim,Germany).

Target Strains and Cultivation Conditions

The strains species were chosen mainly to represent the mostcommon pathogenic and undesirable microorganisms.

Bacterial Strains and Cultivation. The reference strainsof human pathogens used to test antimicrobial activityincluded gram-positive cocci, Staphylococcus epidermidis(CIP 106510), S. aureus (ATCC 25923) and Micrococcus luteus(NCIMB 8166), and gram-negative bacteria E. coli (ATCC35218), Pseudomonas aeruginosa (ATCC 27853), S. typhimu-rium (LT2) and Listeria monocytogenes (ATCC 19115). Thebacterial strains were grown and maintained on Müller-Hinton (MH) agar plates (bioMérieux, Marcy l’Etoile,France) at 37C for 18 h.

Fungous Strains and Cultivation. The human patho-genic yeasts used in the study were isolated from patients suf-fering from candidosis. These strains were isolated onSabouraud chloramphenicol agar plates (bioMérieux) andidentified by Api ID 32 C-test strips (bioMérieux), accordingto the manufacturer’s recommendations. The isolated andidentified strains were Candida albicans, Candida krusei,Candida tropicalis, Candida parapsilosis, Candida glabrata,Candida dubliniensis and Candida sake. The Candida strainswere grown and maintained on Sabouraud chloramphenicolagar plates at 37C for 24–48 h.

Antimicrobial Activity

The antimicrobial activity was tested by agar diffusion assay(Sreeramulu et al. 2001). The Sabouraud chloramphenicolagar medium (45 g/L) was used to evaluate the anti-Candidaactivity, whereas the MH agar medium (38 g/L) was used forthe evaluation of the antibacterial activity. The correspondingagar medium (20 mL) was poured into Petri dishes (90 mmin diameter). Suspensions of target strain previously incu-bated for 24 h were spread on the plates uniformly, and wells

of 6 mm in diameter were made with a sterile metal tube bymeans of a vacuum pump. Kombucha samples were cen-trifuged at 7,000 rpm for 15 min to remove cell debris(JOUAN Centrifuge BR 4i, Centrifuge BR4i, ThermoFisher,CA). Sterile supernatant was obtained by filtering the super-natant through a sterile microfilter (Microfilter sterile, Sarto-rius; 0.20-mm pore size, Minisart, Palaiseau, France). Sterilesamples (100 ml) were then transferred into the wells in theagar plates previously inoculated with the target strain. Theplates were first kept at 4C for 2 h to allow tea sample predif-fusion and then incubated at 37C (Sreeramulu et al. 2001).The diameter of the inhibition zone was measured after 18 hof incubation.

The antimicrobial activity was evaluated by measuringthe growth inhibition zone surrounding the wells. Eachexperiment was carried out in triplicate and the averagediameter � standard deviation of the inhibition zone wasrecorded.

For the purposes of control and comparison, acetic acidsamples at the same concentration as that of fermented teaafter 21 days were prepared and sterilized by filtration andthen used for antimicrobial testing, as described earlier forfermented tea samples. In the same way, pH 7 samples of fer-mented samples were obtained by adjusting the pH with HCl(1 M) or NaOH (1 M). Heat-denatured fermented sampleswere treated at 120C for 20 min. They were then sterilized byfiltration and tested for their antimicrobial activity in thesame way as described previously.

RESULTS AND DISCUSSION

Screening of Kombucha AntibacterialActivity

The antimicrobial activity of kombucha tested under differ-ent conditions against the studied pathogenic microorgan-isms is presented in Table 1. Kombucha samples were testedboth at their acidic pH as they are produced and after theirneutralization (pH 7.0). Heat-treated samples were tested tocontrol the thermostability of the active components in orderto confirm their proteic nature. Both kombucha preparationsexhibited activities against all the gram-negative and gram-positive tested bacteria. In both fermented teas, the activitieswere comparable with a slightly higher potential to thatnoted with the kombucha prepared from green tea. Inhibi-tion diameters ranged from 12 to 22 mm for the green fer-mented tea, while it varied from 10.5 to 19 mm for blackfermented tea.

Kombucha exhibited its strongest antimicrobial effectagainst S. epidermidis, M. luteus, L. monocytogenes andP. aeruginosa (inhibition zone � 18 mm). Acidified green teawas found to be inhibitory toward all of the tested bacteria,but acidified black tea was selectively active only against

H. BATTIKH ET AL. ANTIMICROBIAL ACTIVITIES OF FERMENTED TEAS


L. monocytogenes and P. aeruginosa. In these cases, the notedinhibition was not the same as that found for fermented tea.Moreover, in most cases, kombucha preparations have notpreserved their activity when their pH was adjusted to 7, withthe exception of S. epidermidis and M. luteus. Unfermentedtea samples had almost no antimicrobial activity againsttarget microorganisms, except for S. epidermidis, M. luteusand L. monocytogenes.

It was also noticed that kombucha teas exerted an antimi-crobial activity after thermal denaturation against all thetarget strains, except for L. monocytogenes.

In the case of black fermented tea, the recorded antibacte-rial activity against L. monocytogenes is considered to berelated to the organic acid effect. No activities were revealedwhen the pH was neutralized. Furthermore, the activity wasstrengthened when the infusion was acidified with acetic acid.However, the behavior of the same strain was different interms of the green fermented tea, where the activity wasimproved by tea acidification and such activity remained con-stant after heat treatment. As a result, the chemical composi-tion of both fermented teas would be completely different.

This finding means that the antibacterial activity observedis not exclusively due to the acetic or other organic acids, but italso implies that other components that are biologicallyactive, such as bacteriocins, proteins, enzymes and tea-derived phenolic compounds, may be involved. This resultwas in agreement with other studies (Sreeramulu et al. 2000,2001).

Greenwalt et al. (1998) tested kombucha that originatedfrom different concentrations of black and green teas andfound an antimicrobial activity against gram-positive andgram-negative organisms (A. tumefaciens,Bacillus cereus,Sal-monella choleraesuis serotype Typhimurium, S. aureus andE. coli) and attributed the resulting activities to its acetic acidcontent. The differences in concentrations between the basicinfusions, the fermentation duration, the antimicrobialmethod and the control extracts used may explain theseresults. In his study, Greenwalt et al. (1998) used the absor-bent disc method and the 9-day fermented kombucha andcompared only the neutralized and the unfermented formwith the fermented extracts.

Screening for Kombucha Antifungal Activity

The results of the antifungal activity of kombucha underdifferent conditions are presented in Table 2. All the patho-genic yeasts tested except C. krusei were found to be sensi-tive to kombucha beverages. However, the spectrum of theantifungal activity was different. In fact, green fermented tea(KGT) was active against C. glabrata, C. parapsilosis, C. sake,C. dubliniensis and C. albicans. In comparison, black fer-mented tea (KBT) was able to inhibit C. tropicalis, in additionto these yeasts, without having any effect on C. parapsilosisTA

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and C. sake. It was noticed that only C. glabrata was inhibitedby the unfermented tea. As a result, the fermentation processcontributes to the improvement of the antifungal activity.

In most cases, the antifungal activity exerted by acidifiedtea samples and after heating, depending on kombucha,increased, decreased or even disappeared in the case of C. al-bicans. These results have proved the antimicrobial effects ofthe acetic acid produced during kombucha preparation. Italso highlights its strong effect on the particular yeast andimplies the presence of an antimicrobial component otherthan acetic acid as well as proteins. In addition, neutralizedkombucha has not preserved any antifungal activity. Theseobservations are in agreement with the findings of otherstudies (Sreeramulu et al. 2000, 2001), but it should be notedthat the antifungal activity is not well studied in the literature.Greenwalt et al. (1998) tested the antimicrobial potentials ofkombucha prepared from both black and green tea on theninth day of fermentation against C. albicans but did not findany activity. More recently, Sreeramulu et al. (2000) demon-strated that kombucha prepared from black tea was able toinhibit C. albicans from the sixth day of fermentation to the14th day.

CONCLUSION

The results of this investigation have shown that after 21 daysof fermentation, kombucha still exerts a considerable antimi-crobial activity. Thus, all the tested microorganisms werefound to be susceptible to the fermented black (KBT) andgreen (KGT) teas. A relatively higher antimicrobial potentialwas observed with the green fermented tea (KGT), whereasunfermented teas did not exhibit any antimicrobial proper-ties. Interestingly, kombucha teas exerted antifungal activityagainst a wide range of pathogenic Candida involved inseveral candidoses. Moreover, this study highlighted the dif-ference between the activities of kombucha prepared fromblack tea and that from green tea, and demonstrated that eachbeverage was characterized by a specific spectrum of antimi-crobial activity.

It was also shown that the antimicrobial activity revealedwas not only the result of acetic acid or organic acids. Otherbiologically active components may be involved in theobserved activity such as bacteriocins, proteins and enzymesin addition to the tea-derived phenolic compounds.Althoughthese results were found to be very promising, furthersystematic investigations are needed in order to characterizethe active component.

ACKNOWLEDGMENT

The authors would like to thank Professor Mickeal Andersonfrom the Ceramic School in Staffordshire University for hishelp with English.TA

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H. BATTIKH ET AL. ANTIMICROBIAL ACTIVITIES OF FERMENTED TEAS


REFERENCES

BALENTINE, D.A. 1997. Special issue: Tea and health. Crit. Rev.Food Sci. Nutr. 8, 691–692.

BLANC, P.J. 1996. Characterization of the tea fungus metabolites.Biotechnol. Lett. 18, 139–142.

CHEN, C. and LIU, B.Y. 2000. Changes in major components oftea fungus metabolites during prolonged fermentation. J. Appl.Microbiol. 89, 834–839.

DUFRESNE, C. and FARNWORTH, E. 2000. Tea, Kombucha andhealth: A review. Food Res. Intern. 33, 409–421.

FRANK, G.W. 1995. Kombucha: Healthy Beverage and NaturalRemedy from the Far East, Wilhelm Ennsthaler, Steyr, Austria.

GREENWALT, C.J., LEDFORD, R.A. and STEINKRAUS, K.H.1998. Determination and characterization of the antimicrobialactivity of the fermented tea kombucha. Lebensm. Wiss.Technol. 31, 291–296.

GREENWALT, C.J., STEINKRAUS, K.H. and LEDFORD, R.A.2000. Kombucha, the fermented tea: Microbiology,composition and claimed health effects. J. Food Prot. 63,976–981.

HARA, Y., LUO, S.J., WICKREMASHINGHE, R.L. andYAMANISHI, T. 1995a. Botany (of tea). Food Rev. Int. 11,371–374.

HARA, Y., LUO, S.J., WICKREMASHINGHE, R.L. andYAMANISHI, T. 1995b. Processing tea. Food Rev. Int. 11,409–434.

HARA, Y., LUO, S.J., WICKREMASHINGHE, R.L. andYAMANISHI, T. 1995c. Biochemistry of processing black tea.Food Rev. Int. 11, 457–471.

HOBBS, C. 1995. Kombucha Manchurian Tea Mushroom: TheEssential Guide, Botanica Press, Santa Cruz, CA.

JANKOVIC, I. and STOJANOVIC, M. 1994. Microbial andchemical composition, growth, therapeutical and antimicrobialcharacteristics of tea fungus. Mikrobiologija 33, 25–34.

JAYABALAN, R., MARIMUTHU, S. and SWAMINATHAN, K.2007. Changes in content of organic acids and tea polyphenolsduring kombucha tea fermentation. Food Chem. 102, 392–398.

LIU, C.H., HSU, W.H., LEE, F.L. and LIAO, C.C. 1996. Theisolation and identification of microbes from a fermented teabeverage, Haipao, and their interactions during Haipaofermentation. Food Microbiol. 13, 407–415.

MALBAŠA, R., LONCAR, E. and DJURIC, M. 2008. Comparisonof the products of kombucha fermentation on sucrose andmolasses. Food Chem. 106, 1039–1045.

MAYSER, P., FROMME, S., LEITZMANN, C. and GRÜNDER, K.1995. The yeast spectrum of the “tea fungus kombucha”.Mycoses 38, 289–295.

REISS, J. 1994. Influence of different sugars on the metabolism ofthe tea fungus. Z Lebensm. Unters Forsch. A 198, 258–261.

SREERAMULU, G., ZHU, Y. and KNOL, W. 2000. Kombuchafermentation and its antimicrobial activity. J. Agric. FoodChem. 48, 2589–2594.

SREERAMULU, G., ZHU, Y. and KNOL, W. 2001.Characterization of antimicrobial activity in kombuchafermentation. Acta Biotechnol. 21, 49–56.

STEINKRAUS, K.H., SHAPIRO, K.B., HOTCHKISS, J.H. andMORTLOCK, R.P. 1996. Investigations into the antibioticactivity of tea fungus/kombucha beverage. Acta Biotechnol. 16,199–205.

TEOH, A.L., HEARDB, G. and COX, J. 2004. Yeast ecology ofkombucha fermentation. Int. J. Food Microbiol. 95, 119–126.

TIETZE, H.W. 1995. Kombucha: The Miracle Fungus, 6th Ed.,Phree Books, Bermgui, Australia. 72 p.

WHEELER, D.S. and WHEELER, W.J. 2004. The medicinalchemistry of tea. Drug Dev. Res. 61, 45–65.

YANG, Z.W., JI, B.P., ZHOU, F., LI, B., LUO, Y., YANG, L. and LI,T. 2009. Hypocholesterolaemic and antioxidant effects ofkombucha tea in high-cholesterol fed mice. J. Sci. Food Agric.89, 150–157.



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ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF BLACK AND GREEN KOMBUCHA TEAS