• The Korean Journal of Ecology
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• v.22 no.1
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• pp.45-50
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• 1999

A bacteriocin-producing strain was isolated from kimchi at the early stage of kimchi fermentation. It was identified as Lactococcus lactis by morphological, cultural and physiological characteristics and partial sequence of 16S rDNA. The bacteriocin from isolate had antimicrobial activity against gram positive pathogenic bacteria, such as Listeria monocytogenes. Staphylococcus aureus and several strains of lactic acid bacteria but not to gram negative bacteria, Yersinia enterocolitica. The bacteriocin was sensitive to protease, protease ⅩⅣ, a-chymotrypsin and pepsin but not to lipase, trypsin and lysozyme. The bacteriocin activity was stable at pH 2-11 and temperature of 100 for 10 min. Thus, Listeria monocytogenes could be inhibited by Lactococcus lactis at early stage of fermentation.

• 한국유가공학회:학술대회논문집
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• 1996.11a
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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.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.291-295
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• 2010

A novel bacteriocin produced by Streptococcus parauberis Z49 strain was characterized and efficiently extracted from fermented cultures by use of aqueous two-phase systems. The nisin-like bacteriocin, which was active even after a heat treatment at $121^{\circ}C$ for 15 min and in the broad pH range from 2 to 12, showed inhibition of bacterial growth of Micrococcus luteus, Lactobacillus spp., Lactobacillus fermentum, Enterococcus faecium, Listereia monocytogenes, and Pseudomonas fluorescens. Optimal conditions of PEG 600/$Na_2SO_4$ aqueous two-phase systems for the simple and rapid extraction of a novel bacteriocin were determined to be PEG 600 15%, $Na_2SO_4$ 30%, and NaCl 8%, where the bacteriocin was concentrated in PEG layer.

• Korean Journal of Microbiology
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• v.30 no.4
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• pp.265-268
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• 1992

In this study, we want to detect bacteriocin production in purple nonsulfur bacteria. As a results, it was showed that bacteriocin produced between some strains of Rhodobacter capsulatus, Rhodobacter sphaeroides and Rhodocyclus gelatinosus. In particular, it was appeared that cell membrane-bound bacteriocin was also produced by Rhodobacter capsulatus ATCC 17016.

• Food Science of Animal Resources
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• v.39 no.6
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• pp.1015-1020
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• 2019

Staphylococcus aureus is a representative pathogenic bacterium carefully controlled in the dairy industry because it causes bovine mastitis and thus, can enter the dairy chain. Furthermore, the emergence of multi-drug resistant S. aureus is a big problem. We previously isolated a Lactococcus lactis strain producing a bacteriocin that exhibited strong antimicrobial activity against S. aureus. In this study, we investigated the synergistic inhibition of S. aureus by the bacteriocin and a bacteriophage (SAP84) which is specific to the organism. The bacteriocin (12.5-100 AU/mL) inhibited the growth of S. aureus KCTC 3881 in a dose-dependent manner, as did the bacteriophage SAP84 (0.001-1 MOI; multiplicity of infection). Co-treatment with the bacteriocin (100 AU/mL) and the bacteriophage (0.1 MOI) significantly inhibited the growth of S. aureus compared to each treatment alone (bacteriocin or bacteriophage), indicating the two components showed synergistic inhibition of S. aureus. Therefore, the bacteriocin and bacteriophage combination can be used as a good strategy for controlling pathogenic bacteria.

• Food Science of Animal Resources
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• v.38 no.1
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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.

• Food Science of Animal Resources
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• v.38 no.6
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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.

• Microbiology and Biotechnology Letters
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• v.26 no.6
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• pp.523-528
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• 1998

We isolated microorganism secreting antimicrobial substance from tomato and identified as Enterococcus faecium. This substance was completely inactivated by pretense treatment and retained activity after catalase treatment. This result indicated that the antimicrobial activity of this substance was due to proteinaceous substance known as bacteriocin. The bacteriocin inhibited growth of Gram positive bacteria, such as Listeria monocytogenes, Leuconostoc mesenteroides, Lactobacillus plantarum, Streptococcus agalactiae, Streptococcus pyrogenes, and Gram negative bacteria, such as Pseudomonas aeruginosa. Purification of the bacteriocin was achieved by ethanol precipitation, ion exchange chromatography on CM Sepharose CL-6B, and gel filtration on Sephacryl S-100 HR. After these purification steps, the specific activity of the bacteriocin was increased 35.8 fold compared with culture broth. Purified bacteriocin was shown single band on SDS-PAGE and molecular weight was estimated 51 kDa. The residual activity of this bacteriocin was 3.3% at 10$0^{\circ}C$ for 60 min, and this bacteriocin was stable at pH 2~7.

• Microbiology and Biotechnology Letters
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• v.17 no.2
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• pp.94-99
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• 1989

Seven gtrains of Lactobacillus produce bacteriocin being active for Lacidophilus. All strains producing bacteriocin were found to be L. acidophilus except with one strain of L. gasseri. The maximum activity of bacteriocin produced by Lactobacillus strains was obtained at a middle or late stage of the log phase, or a early stage of the stationary phase. After the maximum was reached, however, the activity was rapidly decreased. The bacteriocins were inactivated easily by the treatment with proteolytic enzymes but not with nucleolytic enzymes, suggesting that the bacteriocin was proteinaceous. The bacteriocins were different from the other previously reported lactobacillus bacteriocin in their flexibility to the treatment at 10$0^{\circ}C$. Bacteriocins of L. acidophilus ATCC 9857 and 4357 decreased in activity by the treatment with diethylether, presumably the bacteriocin contained of a lipid component. It sums likely that L. acidophilus A4 bacteriocin adsorb to a regularly arrayed layer of the cell wall.

• Journal of Dairy Science and Biotechnology
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• v.15 no.1
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• pp.21-26
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• 1997

Lactobacillus acidophilus 223, 606, and NCFM-F among 21 isolated from fecal contents of humans demonstrated inhibitory activity 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 pH were responsible for inhibitory action. All of the producer strains were resistant to their own bacteriocin(s). The bacteriocin(s) were purified by ammonium sulfate precipitation, gel chromatography and ion exchange chromatography for further characterization. The bacteriocin(s) of human origin exhibited similar characteristics.