• Journal of Life Science
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• v.14 no.4
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• pp.683-688
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• 2004

A bacteriocin-producing lactic acid bacteria was isolated from Kimchi on MRS selective media with the use of Lactobacillus delbrueckii subsp. delbrueckii as an indicator strain. The strain YH-10 was identified as Lactococcus lactis subsp. lactis through the API test. The crude bacteriocin (freeze-dried 50% ammonium sulfate precipitate of culture supernatant) produced by the strain was named as lacticin YH-10. Lacticin YH-10 showed the growth inhibitory activity against Gram positive pathogenic bacteria and other lactic acid bacteria. The bacteriocin was inactivated by proteases such as protamex and aroase AP-10 and partially inactivated by amylase, proteinase K, trypsin, and papain. The lacticin YH-10 remained its activity with the treatment of heat at 10$0^{\circ}C$ for 60 min or the changes of pH 2 to 11. However, the activity was lost at high pH combined with the exposure to 10$0^{\circ}C$. The bacteriocin production of the strain was started in the exponential phase and stopped in the stationary phase. The approximate molecular mass of the bacteriocin produced by the strain was approximate 14 kDa in the analysis on SDS-PAGE.