• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.774-783
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• 2007

In the present study, acidocin 1B, a bacteriocin produced by Lactobacillus acidophilus GP 1B, exhibited profound inhibitory activity against a variety of LAB and pathogens, including Gram-negative bacteria, and its mode of action was to destabilize the cell wall, thereby resulting in bactericidal lysis. Acidocin 1B was found to be heat stable, because it lost no activity when it was heated up to $95^{\circ}C$ for 60 min. It retained approximately 67% of the initial activity after storage for 30 days at $4^{\circ}C$, and 50% of its initial activity after 30 days at $25^{\circ}C$ and $37^{\circ}C$. The molecular mass of acidocin 1B was estimated to be 4,214.65 Da by mass spectrometry. Plasmid curing results indicated that a plasmid, designated as pLA1B, seemed to be responsible for both acidocin 1B production and host immunity, and that the pLA1B could be transformed into competent cells of L. acidophilus ATCC 43121 by electroporation. Our findings indicate that the acidocin 1B and its producer strain may have potential value as a biopreservative in food systems.

• Journal of Dairy Science and Biotechnology
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• 제21권2호
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• pp.114-119
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• 2003

Lactobacillus acidophilus CP4A 균주가 생산하는 acidocin 4A를 정제하고자 ammonium sulphate 침전법 , Octyl-sepharose CL-4B column chromatography, $C_{18}$ Sep-Pak cartridge, $C_{18}$ RP HPLC, HPLC gel filtration을 실시하였고 tricine SDS-PAGE를 통해 약 4.1 kDa의 박테리오신임을 확인하였다. Acidocin 4A의 항균작용 기작을 L. delbrueckii subsp. lactis ATCC 4797을 대상으로 TEM을 이용해 관찰한 결과 세포벽이 해리되고 세포벽사이로 세포내용물이 용출되어 궁극적으로 cell lysis가 일어나는 bacteriolytic 현상을 확인하였다. 또한, acidocin 4A의 생산에 관련된 유전자의 존재 위치를 파악하고자 EtBr을 이용한 curing방법을 실시하였으며 그 결과 약 20 kb 크기의 plasmid에 acidocin 4A 생산과 자체 면역에 관련된 유전자가 존재함을 알 수 있었다.