• 한국축산식품학회지
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• 제38권5호
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• pp.1064-1079
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• 2018

In this study, the antimicrobial activity of a bacteriocin produced by Enterococcus faecalis KT11, isolated from traditional Kargı Tulum cheese, was determined, and bacteriocin KT11 was partially characterized. The results showed that bacteriocin KT11 was antagonistically effective against various Gram-positive and Gram-negative test bacteria, including vancomycin- and/or methicillin-resistant bacteria. The activity of bacteriocin KT11 was completely abolished after treatment with proteolytic enzymes (proteinase K, ${\alpha}$-chymotrypsin, protease and trypsin), which demonstrates the proteinaceous nature of this bacteriocin. Additionally, bacteriocin KT11 remained stable at pH values ranging from 2 to 11 and after autoclaving at $121^{\circ}C$ for 30 min. In addition, the activity of bacteriocin KT11 was stable after treatment with several surfactants (EDTA, SDS, Triton X-100, Tween 80 and urea) and organic solvents (chloroform, propanol, methanol, ethyl alcohol, acetone, hexane and ethyl ether). Cell-free supernatant of E. faecalis KT11 was subjected to ammonium sulfate precipitation and then desalted by using a 3.5-kDa cut-off dialysis membrane. The bacteriocin activity was determined to be 711 AU/mL in the dialysate. After tricine-SDS-PAGE analysis, one peptide band, which had a molecular weight of ~3.5 kDa, exhibited antimicrobial activity. Because the bacteriocin KT11, isolated from E. faecalis KT11, exhibits a broad antimicrobial spectrum, heat stability and stability over a wide pH range, this bacteriocin can be used as a potential bio-preservative in foods. Additionally, bacteriocin KT11 alone or in combination with conventional antibiotics may provide a therapeutic option for the treatment of multidrug-resistant clinical pathogens after further in vivo studies.

• 한국식품저장유통학회지
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• 제10권3호
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• pp.411-416
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• 2003

쌀에 존재하며 토양미생물인 Pseudomonas putida 21025를 미강에 배양하여 생성되는 bacteriocin을 미강 필름에 첨가하여 미강필름의 저상성향상을 조사하였다. Pseudomonas putida 21025를 접종한 미강 액체배지는 초기배지 pH 6.48로 자연그대로의 미강 액체배지를 이용하여 항온 배양기에 3$0^{\circ}C$, 150 rpm으로 33시간 배양하여 bacteriocin을 생성하였다. bacteriocin 첨가 후, 필름 가공시에는 bacteriocin의 생산과 안정성을 고려하여 pH 9.4로 조절한 후 한 시간 이내 교반, 8$0^{\circ}C$로 가열 후 2분간 유지의 총시간을 20분 이내로 하여 미강 단백질 필름을 제조하였다. 이러한 방법으로 제조한 미강 단백질 필름의 아미노태 질소함량을 조사한 결과 20% bacteriocin을 첨가한 미강 단백질 필름이 첨가하지 않은 단백질 필름 보다 아미노태 질소함량이 낮은 것으로 나타났다. 따라서 bacteriocin이 미강 단백질 필름 코팅재의 저장기간 향상에 도움을 줄 것으로 보인다.

• 한국축산식품학회지
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• 제38권6호
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• pp.1315-1321
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• 2018

Bacteriocin is ribosomally synthesized by bacteria and inhibits closely related species. In this study we aimed at isolating lactic acid bacteria producing bacteriocin presenting anti-staphylococcal activity. A Lactococcus lactis strain was isolated from kimchi for the purpose and identified by 16S rRNA gene sequencing. As preliminary tests, optimal culture conditions, stabilities against heat, solvents, and enzymes treatments, and type of action (bacteriostatic or bactericidal) of the bacteriocin were investigated. The optimal culture conditions for production of the bacteriocin were MRS broth medium and $25^{\circ}C$ and $30^{\circ}C$ culture temperatures. The bacteriocin was acidic and the activity was abolished by a protease treatment. Its stability was maintained at $100^{\circ}C$ for 15 min and under treatments of various organic solvents such as methanol, ethanol, acetone, acetonitrile, and chloroform. Finally, the bacteriocin showed bactericidal action against Staphylococcus aureus where 200 AU/mL of the bacteriocin decreased the viable cell count (CFU/mL) of S. aureus by 2.5 log scale, compared with a control (no bacteriocin added) after 4-h incubation.

• 한국유가공학회:학술대회논문집
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• 한국유가공기술과학회 1996년도 추계 제43회 유가공 심포지움
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• pp.30-34
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• 1996

Twenty seven strains of Lactobacillus acidophilus among 92 isolated from fecal contents of humans, pigs, calves, chickens, rodents and turkeys demonstrated inhibitory attributed to bacteriocin(s). The bacteriocin(s) were heat stable and nondialyzable proteinous compounds and exhibited narrow inhibitory spectra of activity. Neither hydrogen peroxide nor low pH were responsible for inhibitory action. All of the producer strains were resistant to their own bacteriocin or bacteriocin(s) produced by other strains. The bacteriocins from several strains from different host species were purified for further characterization. The bacteriocin(s) all exhibited similar characteristics.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.275-280
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• 2001

Bacteriocin J105 is a proteinaceous inhibitory substance produced by Latococcus latis subsp. lactis j105 isolated from Kimchi. Bacteriocin J105 was purified to homogeneity by the pH-dependent adsorption-desorption method and reverse-phase HPLC from the culture broth of Lactococcus lactis subsp. lactis J105. Purification of bacteriocin J105 resulted in a 1.47-fold increase in the specific activity and the recovery was 1.5%. Its molecular mass measured by the electrophoretic pattern in the sodium, dodecyl sulfate polyacrylamide gel was about 3.4 kDa. It was stable at $121^{\circ}C$ for 15 min at pH between 2 and 4. However, at pH above 5, bacteriocin was rapidly inactivated. Twenty-one residues from the N-terminal portion of bacteriocin J105 were sequenced using sequence analysis of lantibiotics. Bacteriocin J105 showed significant homology with known nisin A from lactic acid bacteria.

• 한국식물병리학회지
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• 제12권2호
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• pp.169-175
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• 1996

콩 불마름병균 Xanthomonas campestris pv. glycines 8ra는 X. c. pv. vesicatoria에 길항력이 있는 bacteriocin인 glycinecin을 생성 분비한다. Bacteriocin 생성 분비 능력이 있는 콩 불마름병균을 효과적인 생물학적 방제원으로 활용하기 위해서는 좀더 체계적인 연구가 필요하여, bacteriocin 생성에 관계되는 유전자의 분리를 시도하였다. 약 2,000개의 Xanthomonas campestris pv. glycines 8ra cosmid library에서 bacteriocin의 생성 분비 능력을 조사하여 다섯 개의 clone을, pG011, pG0113, pG33과 pG35, 선발하였다. 그중 한 clone pG08을 임의로 선택하여 plasmid DNA를 분리하였다. Plasmid pG08에서 약 6.0 kb의 DNA를 떼어내어 다른 plasmid vector에 넣은 subclone pBL5는 bacteriocin의 생성 분비 능력이 있었다. Plasmid pG08을 제한효소 처리후 다시 접함시켜 만든 몇 개의 subclone과 pBL5의 제한효소 지도를 비교 분석한 결과 약 3.0 kb의 BamHI-HindIII 부분의 DNA가 bacteriocin의 생성에 관계함을 알았다.

• 한국축산식품학회지
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• 제41권1호
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• pp.164-171
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• 2021

Listeria monocytogenes is a representative foodborne pathogen and causes listeriosis. Enterococcus faecium CJNU 2524 was confirmed to produce a bacteriocin with anti-listerial activity. To establish optimal culture conditions for the production of the bacteriocin from E. faecium CJNU 2524, different media (MRS and BHI broth) and temperatures (25℃, 30℃, and 37℃) were investigated. The results showed that the optimal culture conditions were MRS broth and 25℃ or 30℃ temperatures. The crude bacteriocin was stable in a broad range of pH conditions (2.0-10.0), temperatures (60℃-100℃), and organic solvents (methanol, ethanol, acetone, acetonitrile, and chloroform). The bacteriocin activity was abolished when treated with protease but not α-amylase or lipase, indicating the proteinaceous nature of the bacteriocin. Finally, the bacteriocin showed a bactericidal mode of action against L. monocytogenes. Therefore, it can be a biopreservative candidate for controlling L. monocytogenes in dairy and meat products.

• Applied Biological Chemistry
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• 제46권4호
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• pp.285-290
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• 2003

경제성과 항균력을 갖춘 미강단백질 필름을 개발하기위한 연구의 일환으로 미강배지에서 bacteriocin을 생성할 수 있는 균주를 선별하고 그 특성을 조사하였다. 그 결과, Pseudomonas aeruginosa 9027에 대한 항균효과를 지닌 Pseudomonas putida 21025를 선별하였으며, 이 균이 생성한 bacteriocin은 쌀에 존재하는 미생물 및 토양미생물에 대하여 넓은 항균활성을 갖는 것으로 나타났다. 지금까지 이용되고 있는 미강단백질 추출 조건에 대한 적합성을 알아보기 위해 bacteriocin의 특성을 조사하였다. Pseudomonas putidia 21025에서 생성되는 bacteriocin은 $50^{\circ}C$이상에서는 한 시간 후 활성이 저하되었으며, 헥산과 에탄올을 제외한 메탄올, 톨루엔, 클로로포름, 아세톤, 메틸 를로로포름등의 유기용매에서 활성이 현저하게 저하되었다. 그러나, 이 bacteriocin은 pH 6.0-9.0에서 2시간동안 안정하였고, $50^{\circ}C$이하에서 안정하였으며, 에탄올에 대하여 3시간동안 안정한 특성을 가지고 있는 것으로 나타났다. 또한 부분정제한 bacteriocin의 분자량은 약 21.6 kDa로 비교적 작은 분자량을 나타내었다.

• 한국축산식품학회지
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• 제38권1호
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• pp.88-98
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• 2018

In this study, we isolated and characterized a bacteriocin-producing strain and two bacteriophages (P4, A3), showing antimicrobial effects against Clostridium perfringens, from chicken and swine feces by the spot-on-the lawn antagonism method. The selected strain was identified as Streptococcus hyointestinalis by 16S rRNA gene sequencing. The bacteriocin from the isolated strain exhibited strong inhibitory activity against four strains of C. perfringens and all the tested strains of Listeria monocytogenes, and the bacteriocin were highly heat- and pH-stable even at pH 2, pH 10 and $121^{\circ}C$ for 15 min. We also evaluated the combined effects of the isolated bacteriocin and phages. Combining the phage treatments and bacteriocin resulted in a synergetic effect compared with the phage or the bacteriocin alone. In addition, during the probiotic test, the bacteriocin-producing S. hyointestinalis B19 strain reduced the population of C. perfringens significantly. Treatment with S. hyointestinalis B19 and a cocktail of lytic bacteriophages eradicated the C. perfringens KCTC $3269^T$, completely. Consequently, the isolated bacteriocin and bacteriophages represent candidates for effective biocontrol of C. perfringens, and bacteriocin-producing S. hyointestinalis B19 is a potential probiotic candidate for use in domestic animals.

• 한국축산식품학회지
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• 제35권4호
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• pp.473-478
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• 2015

The aim of this study was to screen and In vitro characterize the properties of bacteriocin produced by lactic acid bacteria isolated from Vietnamese fermented pork (Nem chua). One hundred and fifty LAB were isolated from ten samples of Nem chua and screened for bacteriocin-producing lactic acid bacteria. Antimicrobial activity of bacteriocin was carried out by spot on lawn method against both gram positive and gram negative bacteria. One isolate, assigned as KL-1, produced bacteriocin and showed inhibitory activity against Lactobacillus sakei, Leuconostoc mesenteroides and Enterococcus faecalis. To characterize the bacteriocin-producing strain, optimum temperature, incubation period for maximum bacteriocin production and identification of bacteriocin-producing strain were determined. It was found that the optimum cultivation temperature of the strain to produce the maximum bacteriocin activity (12,800 AU/mL) was obtained at 30℃. Meanwhile, bacteriocin production at 6,400 AU/mL was found when culturing the strain at 37℃ and 42℃. The isolate KL-1 was identified as L. plantarum. Antimicrobial activity of cell-free supernatant was completely inhibited by proteolytic enzyme of trypsin, alpha-chymotrypsin and proteinase K. Bacteriocin activity was stable at high temperature up to 100℃ for 10 min and at 4℃ storage for 2 d. However, the longer heating at 100℃ and 4℃ storage, its activity was reduced.