COMPARISON OF THE ANTIBACTERIAL ACTIVITY OF COW MILK KEFIR AND GOAT MILK KEFIR AGAINST BACTERIA Bacillus cereus
Abstract: Kefir is fermented
milk and comes from the Caucasus. Kefir is made by inoculating cow milk, goat
or sheep with kefir grain. Kefir contains 0.5–1.0% alcohol and 0.9 to 1.1%
lactic acid. This product is very popular in the Soviet Union, where the
consumption of kefir reach 4.5 kg per capita per year. Kefir made from
pasteurized milk and fermented with kefir grain, kefir grain is white seeds
from bacteria colony, such as Streptococcus sp., Lactobacilli and some types of
yeast/yeast apatogen. As a probiotic drink, kefir contains bacteria of lactic
acid and acetic acid bacteria in kefir are giving acidity and produces
secondary metabolites that bacteriocins that kill pathogenic bacteria such as
Bacillus cereus.
Method: This study used cow milk and goat milk kefir as a starting
material, to produce a cow milk kefir and goat milk kefir. Cow milk kefir and
goat milk kefir were compared antibacterial activity against Bacillus cereus.
Previously each made 3 variations of the concentration of 2%, 4%, and 6% kefir
grains were added cow milk and goat milk. Antibacterial activity tested using
Kirby Bauer method so that the observation a clear zone formed on the media was
the inhibition activity of the bacterium Bacillus cereus. The results were
analyzed by ANOVA, Mann Whitney, and Tukey with a significance of 95%.
Result: The results showed that goat milk kefir has better antibacterial
activity against Bacillus cereus compared to cow milk kefir. Goat milk kefir
with kefir seeds concentration of 6% has the best antibacterial activity with
inhibition zone diameter of 6 mm.
Author: Dwi Suhartanti, Ryan
Septian
Journal Code: jpkesmasgg140003
