Kombucha as an antimicrobial source pt.2

1. Kombucha Tea Fungus as
an Antimicrobial Source
Stephanie Rodriguez
RISE Summer Bridge Program 2015

2. Introduction
Kombucha 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.

3. Kombucha tea has been claimed to have these beneficial effects upon
human health:
Detoxify the blood
Regeneration of cell walls
Alleviate arthritis, rheumatism, and gout symptoms
Balance intestinal flora and reduce obesity
Heal bladder infection and reduce kidney calcification
Protect against diabetes and increase the body’s resistance to cancer
Antibiotic effect against bacteria, viruses, and yeasts
Enhance metabolism and the immune system
Relieve headaches, bronchitis and asthma
Reduce menstrual and menopausal disorders
Improve eyesight and counteract aging

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

5. • 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.

6. 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.

7. 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.

8. 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.

9. 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.

10. • 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.

11. 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

12. 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

13. 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.

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

15. 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.

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

17. 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.

18. Any questions?
Thank you for your attention.