| Summary: | Lactic acid bacteria can be found on many kind of tradisional fermented products of
Indonesian origin. Viability of bacteria on foods affected by many factors, including
processing methods. Processing can shift bacteria population on foods. This research aimed
to isolate lactic acid bacteria from various products with different processing methods prior
to fermentation and to know its antibacterial activity.
In this research, lactic acid bacteria were isolated from various foods, such as usar,
tongcai, kincam, salted radish, teri asin, sedap malam, salted fish, tape singkong and tape
ketan, gatot, tempe, tofu whey, ragi, ampas tahu, and kecutan tahu. Isolation was done by
pour plating method and purification streak plate method on MRS agar containing 1%
CaCO3 and 10 ppm Na-azide. The isolates were identified morphologycally, biochemically,
and physiologically. Antibacterial activity of the isolates tested using agar well-diffusion
assay on cell culture, acidic supernatant, and neutralized supernatant against Staphylococcus
aureus and Escherichia coli.
The lactic acid isolates were identified as Lactobacillus (5 isolates) from kecutan
tahu and ampas tahu, Pediococcus (2 isolates) from ragi tape and salted fish, and
Streptococcus/Enterococcus (9 isolates) from tempe, salted fish, and salted radish. Some of
the isolates showed the antibacteria potency as they able to inhibit the growth of
Staphylococcus aureus and Escherichia coli with inhibition diameter range from 9 to 15
mm. Inhibition of the growth of these patoghenic bacteria were caused by viable cell of
lactic acid bacteria isolates and the acid produced during its growth.
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