Kombucha Tea Fungus as an Antimicrobial Source

Stephanie Rodriguez

RISE Summer Bridge Program 2015

IntroductionKombucha tea is a slightly sweet but slightly acidic refreshing beverage obtained from the infusion of tea leaves by the fermentation of a symbiotic association of bacteria and yeasts forming tea fungus.

It can be produced at home by using mail order or locally available kombucha. Although green tea can be used for preparation, black tea and white sugar are considered its finest substrate.

It is sold worldwide in retail food stores in different flavors and its culture is sold online.

Though it is claimed to be beneficial for medical ailments, very little or no clinical evidence is available for that and as always there are many misconceptions and conceptions regarding this beverage.

Kombucha tea has been claimed to have these beneficial effects upon human health:Detoxify the bloodRegeneration of cell wallsAlleviate arthritis, rheumatism, and gout symptomsBalance intestinal flora and reduce obesityHeal bladder infection and reduce kidney calcificationProtect against diabetes and increase the body’s resistance to cancer

Antibiotic effect against bacteria, viruses, and yeastsEnhance metabolism and the immune systemRelieve headaches, bronchitis and asthmaReduce menstrual and menopausal disorders Improve eyesight and counteract aging

Kombucha tea can be divided into two portions:• A floating cellulosic pellicle layer• Sour liquid broth

• Helicobacter pylori is the most common chronic infection in humans. It causes abdominal pain, weight loss, nausea, and vomiting. It also impairs absorption of nutrients by altering the balance of iron, vitamin B12, folic acid, alpha-tocopherol, vitamin C, and beta-carotene.

• Escherichia coli is associated with a severe diarrheal disease called hemolytic uremic syndrome.

• S. pneumonia is the most frequent cause of middle ear infections.

• Staphylococcus aureus causes more than one half of all staphylococcal infections in most communities.

Purpose

After considering the widespread misconceptions and conceptions regarding kombucha tea, I recognized the need to put an end to these reports that claim that drinking kombucha tea can serve as a natural antibiotic because of its antimicrobial properties.

Objective

The objective of this research proposal is to demonstrate kombucha tea’s antimicrobial efficacy or inhibitory activity against pathogenic microorganisms of both Gram-positive and Gram-negative origin.

Hypothesis

If I perform the proper antibiotic tests through the methodology that I have put together and the bacteria show a noticeable decrease in colonies or any signs of change reflecting so, then the kombucha tea fungus will show antimicrobial properties.

Recipe for Kombucha Tea• Tap water (1 L) is boiled and 50 g sucrose is stirred in.

• 5 g of black tea leaves are added and removed after 5 min.

• After cooling, the tea is inoculated with 24 g of tea fungus and poured into a previously sterilized beaker.

• Add 0.2 L of previously fermented kombucha.

• The beaker is covered with a paper towel to keep insects away.

After a few days, a clear thin gel-like membrane will start to form and float. This is the newly formed tea fungus available as a new layer above the old tea fungus which was inoculated to begin the fermentation.

• The tea will start to smell and gas bubbles will appear due to the carbonic acid produced during the fermentation.

• After 10 to 14 days, a new tea fungus will have developed on the surface of the tea as a disc of 2-cm thickness covering the whole diameter of the beaker.

• The newly formed tea fungus is removed with a spoon and kept in a small volume of fermented tea. The remaining beverage is filtered and stored in capped bottle.

It is remarkable that 50 g sucrose/L provide the optimal concentrations of ethanol and lactic acid. Longer fermentation produces high levels of acids that may pose potential risks when consumed.

Methodology 1. Following the steps on the previous slides, prepare kombucha tea

from different substrates: green tea, jasmine tea, and black tea.

2. In a laboratory, culture two types of common Gram-negative and two types of common Gram positive bacteria each one in 4 agars; in a way that you end up with sixteen agars with four different types of bacteria. I will then separate one agar of each type of bacteria from the rest:

Gram-Negative: Helicobacter pylori and Escherichia coli Gram Positive: S. pneumonia and Staphylococcus aureus

Helicobacter pylori

Escherichia coli S. pneumonia Staphylococcus aureus

3. After growing the bacteria, I will cut twelve .5 cm diameter disks from the tea fungus of each substrate: green tea, jasmine tea, and black tea.

4. I will then place three of these disks of green tea into the four different agars. I will repeat this with the remaining disks of the three substrates in a way that I end with this:

Green Tea

Jasmine Tea Black Tea

5. Using the four agars that I set aside at the beginning, I will perform an antibiotic test with pellet of the known antibiotics for the bacteria and use these as my positive control.

*Amoxicillin for Helicobacter pylori and S. pneumonia

*Ciprofloxacin for Escherichia coli

*Penicillin for Staphylococcus aureus

6. I will now proceed to observe the effects of the tea fungus upon these bacteria; paying close attention to any decrease on bacterial colony count or absence of culture around the disks much like in antibiotic testing.

If the bacteria continues to grow normally, then the tea fungus does not have any antimicrobial properties but; if the growth in bacteria is somehow affected, diminished or no growth is present around the disks then the tea fungus does have antimicrobial properties. Compare the effectiveness by the halos formed by the control group and experimental group for each type of bacteria.

This is the halo I refer to. This halo is the result of the inhibitory effect of the tablets upon the bacteria.

Expected Results

As a result, I expect to prove that kombucha tea has antimicrobial properties and that it can be used as a more natural alternative to antibiotics.

Potential Pitfalls

One possible pitfall would be that the kombucha tea fungus does not present any antimicrobial properties.

References• Antibiotic Testing http://bulldog2.redlands.edu/fac/ben_aronson/hal/index1.htm

• Common Bacteria http://www.lifeextension.com/Protocols/Infections/Bacterial-Infection/Page-03

• Recipe http://www.culturesforhealth.com/how-to-make-kombucha

• Testimonials http://www.kombu.de/english.htm

• Wiley Online Library http://onlinelibrary.wiley.com/doi/10.1111/1541-4337.12073/pdf

• All the pictures are taken from google.

• Sreeramulu G, Zhu Y, Knol W. 2000. Kombucha fermentation and its antimicrobial activity. J Agri Food Chem 48:2589-94.

• Battikh H, Chaieb K, Bakhrouf A, Ammar E. 2012. Antibacterial and antifungal activities of black and green kombucha teas. J Food Biochem 37:231-6.

• Steinkraus KH, Shapiro KB, Hotchkiss JH, Mortlock RP. 1996. Ivestigations into the antibiotic activity of tea fungus/ kombucha beverage. Acta Biotechnol 16:199-205.

Any questions?Thank you for your attention.