김치에서 분리한 Lactococcus sp. JC-3 bacteriocin의 특성

Bacteriocin을 생산하는 유산균을 김치에서 분리하였고 Lactococcus latis subsp. lactis로 확인 되었으며 bacteriocin의 최대생산조건은 $30^{\circ}C$, 6시간으로 다양한 유산균 및 Pseudomonas synsantha, Acetobacter aceti의 생육을 저해하였고 여러 peptidases에 의해 불활성화되었다. 또한 다양한 범위의 pH와 열처리에 안정하였고 SDS-PAGE결과 약 8 Kda으로 확인되었다.

Bacteriocin-producing lactic acid bacteria was isolated from Kimchi using MRS as selective media and Lactobacillus delbruekii subsp. delbruekii as an indicator strain. Strain JC-3 was tentatively identified as Lactococcus latis subsp. lactis through the API test and the bacteriocin produced by JC-3 showed the inhibitory activity against Grampositive pathogens and other lactic acid bacteria. The antimicrobial substance was inactivated by Protamax, Aroase AP-10, Neutrase, R-AMANO and was confirmed to be heating at $100^{\circ}C$. However, it was lost at high pH values showed the highest bacteriocin activity at a culture temperature of $30^{\circ}C$. The bacteriocin was partially purified by ammonium sulfate precipitation, Sep-pak $C_{18}$ cartridge. The apparent molecular mass of the bacteriocin was about 8 Kda, which was determined through the direct detection of bactericidal activity using SDS -PAGE.