Seleksi Galur-Galur Leuconostoc yang Mempunyai Aktivitas Bakteriostatin Terhadap Berbagai Bakteri Indikator

Lactid Acid Bacteria (LAB) are known to produce bacteriocins which have antimicrobi-al activity, and possessed to be developed as antibiotic complement. This study aimed tocharacterize bacteriocins activity from Leuconostoc strains isolated previously from localsources, and to optimize pH and incubation temperature as well. A well diffusion agarassay for zone inhibition method and bacteriocin potency assay performing minimum in-hibition concentration (MIC) have been done. Bacterial indicators used in this study areLeu. mesenteroides TISTR 120, and JCM 6124, Staphylococcus aureus FNCC 0047, Lis-teria monocytogenes FNCC 0156, Escherichia coli FNCC 0183, Pseudomonas aeruginosaFNCC 0063, Salmonella typhi FNCC 0165 and Bacillus subtilis FNCC 0061. Catalase,Trypsin and Protease K were also used for confirmation test. Results revealed that bothLeu. mesenteroides MBF2-5 and MBF7-17 possessed bacteriocin activity although againstLeu. mesenteroides TISTR 120 and JCM 6124 indicators strains. The optimum pH forbacteriocin potency assay for both Leuconostoc strains MBF2-5 and MBF7-17 was pH 6,whereas the optimum incubation temperature was 32 oc with MIC value of 90% and 80%,respectively.