| Summary: | The objectives of this research were to screen and identify lactic acid
bacteria from Indonesian traditional fermented fish. Two hundred lactic acid
bacteria (LAB) isolated from 26 samples of petis, terasi and peda were screened
for the presence of bacteriocin-producer strain using disc diffusion method, agar
spot test, agar well diffusion assay, and critical dilution assay against Pediococcus
acidilactici LB 42 as an indicator strain. Seventy isolates showed inhibitory
activity when tested using disc diffusion assay. Among 70 isolates, 15 isolates
showed inhibitory activity used agar spot test and 10 isolates from those 15
isolates showed inhibitory activity on agar well diffusion assay. The antibacteria
activity from those 10 isolates were tested with critical dilution method and 4
isolates showed highest activity (1.800 AU/ml), i.e. PDM20B12, PD5AM7 and
PD5M3 that were isolated from peda and THL09 isolated from terasi. All of
bacteriocin produced by those four isolates inhibited Pseudomonas fluorescens
but Eschericia coli and Staphylococcus aureus inhibited weak (< 2 mm). All of
those four bacteriocins were stable at high temperature (100
o
C for 20 min), wide
range of pH (3-11) and treatment of tween 20, tween 80 and chloroform. All of
bacteriocins lost their activity when tested using proteinase K, but only
bacteriocin produced by isolate PDM20B12 that lost of activity in treatment of
pepsin, crude papain, and trypsin. Based on observed characteristics, bacteriocins
produced by isolates PDM20B12, PD5AM7, PD5M3, and THL09 belonged to
class II bacteriocin, a low molecular weight and heat stable bacteriocin.
Identification using Bergey�s manual identification method was resulted that all of
isolates were genus Pediococcus. Molecular identification confirmed that LAB
isolates were Pediococcus acidilactici.
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