• 농약과학회지
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• 제2권3호
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• pp.28-35
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• 1998

전국에서 분리한 세균으로부터 항균력이 있는 길항세균들을 먼저 분리한 다음 그중 배양배지 속으로 강력한 항균력을 나타내는 peptide를 분비하는 A405균주를 선발, Biolog System 및 rDNA 염기서열을 이용하여 Bacillus subtilis로 동정하고 이 균주가 생성하는 항균 peptide의 항균력을 조사한 바 Botrytis cinerea, Cercospora sp., Fusarium oxysporum, Penicillium digitatum, Celletotrichum gloeosporioides, Rhizoctonia solani, Pythium ultimum, Pyricularia oryzae등의 식물병원균과 Escherichia coli, Pseudomonas spp. 등의 세균 및 효모인 Candida albicans의 성장도 억제하는 강력한 항균력을 보였다. 또한 이 균주가 생산하는 항균 peptide는 알콜, 아세톤과 같은 유기용매에 내성을 가지고 있었으며 proteinase K와 phenol 처리시에는 항균력이 감소되거나 소실되는 특성을 가지고 있었다. 이 항균 peptide를 SDS-PAGE, Native-PAGE 및 Tris-Tricine 전기영동으로 분자량이 3kDa인 작은 peptide임을 확인하였고 aspartic acid, glycine, serine, glutamine, valine, leucine, isoleucine, proline, tyrocine 등의 9가지 아미노산으로 구성되어 있음을 Amino Acid Analyzer로 확인하였으며 냉동건조한 항균 peptide 50 ug/ml을 체리토마토에 처리하여 과일의 선도유지를 조사한 결과 대조구에 비하여 월등한 선도유지 효과가 있음을 입증하였다.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.225-236
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• 2013

Among several bacteria examined, an antibacterial-producing Lactobacillus strain with probiotic characteristics was selected and identified based on 16S rRNA gene sequencing. Subsequent purification and mode of action of the antibacterial compounds on target cells including E. coli were investigated. Maximum production of the antibacterial compound was recorded at 18 h incubation at $30^{\circ}C$. Interestingly, antibacterial activity remained unchanged after heating at $121^{\circ}C$ for 45 min, 24 h storage in temperature range of $70^{\circ}C$ to room temperature, and 15 min exposure to UV light, and it was stable in the pH of range 2-10. The active compounds were inactivated by proteolytic enzymes, indicating their proteinaceous nature, and, therefore, referred to as bacteriocin-like inhibitory substances. Isolation and partial purification of the effective agent was done by performing ammonium sulfate precipitation and gel filtration chromatography. The molecular mass of the GFC-purified active compound (~3 kDa) was determined by Tris-Tricine SDS-PAGE. To predict the mechanisms of action, transmission electron microscopy (TEM) analysis of ultrathin sections of E. coli before and after antibacterial treatment was carried out. TEM analysis of antibacterial compounds-treated E. coli demonstrated that the completely altered bacteria appear much darker compared with the less altered bacteria, suggesting a change in the cytoplasmic composition. There were also some membrane-bound convoluted structures visible within the completely altered bacteria, which could be attributed to the response of the E. coli to the treatment with the antibacterial compound. According to the in vivo experiments oral administration of L. plantarum HKN01 resulted in recovery of infected BALB/c mice with Salmonella enterica ser. Typhimurium.