Purification and Characterization of the Bacteriocin Produced by Lactococcus sp. KD 28 Isolated from Kimchi

A. The bacteriocin was highly thermostable and resistant to heating at 80℃ for up to an hour but 50 % of the total activity was remained at 100℃ for 30 min. The pH range from 2.0 to 8.0 had no effect on bacteriocin activity and it was not affected by solvents such as acetonitrile, isopropanol, methanol, chloroform and acetone up to 50% concentration. The bacteriocin showed antibacterial activ- ity against M. luteus IAM 1056, Lactobacillus delbrueckii subsp. lactis KCTC 1058, Enterococcus faecium KCTC 3095, Bacillus cereus KCTC 1013, B. subtilis KCTC 1023, Listeria ivanovii subsp. ivanovii KCTC 3444, Staphylococcus aureus subsp. aureus KCTC 1916, B. megaterium KCTC 1098 and B. sphaericus KCTC 1184. The bacteriocin was purified through ammonium sulfate concentration, SP-Sepharose chromatog- raphy and RP-HPLC. The molecular weight was estimated to be abo ut 3.4 kDa by tricine-SDS-PAGE analysis.