• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.179-191
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• 2007

The purpose of this study was to monitor and compare the contamination levels of heterotrophic bacteria and pathogenic bacteria (total coliforms, Escherichia coli O157:H7, Salmonella spp., Vibrio parachaemolyticus, Staphylococcus aureus and Bacillus cereus). The samples collected at fish farms located in the Jeju-island were investigated from March to August in 2006. The contamination levels of S. aureus, B. cereus and Salmonella spp. ranged $0-3.3{\times}10^2 CFU/ml,\;0-2.2{\times}10^2 CFU/ml\;and\;0-5.1{\times}10^1CFU/ml$, respectively, and 85% of moist pellet feeds were contaminated with S. aureus, B. cereus and total coliforms. But total coliforms and E. coli O157:H7 were not detected in oliver flounder (Paralichthys olivaceus). For the production of safe oliver flounder (Paralichthys olivaceus), education of sanitation for employees, control of fish feed, and continuous monitoring for microorganism will be required.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.234-240
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• 2013

This test was performed to evaluate the bactericidal efficacy of Fumagari OPP$^{(R)}$, fumigation disinfectant, containing 20% ortho-phenylphenol against Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium). In preliminary tests, both E. coli and S. typhimurium working culture suspension number (N value) was $4.0{\times}10^8$ CFU/mL. And all of the colony numbers on the carriers exposed the fumigant (n1, n2, n3) were higher than 0.5N1 (the number of bacterial test suspentions by pour plate method), 0.5N2 (the number of bacterial test suspentions by filter membrane method) and 0.5N1, respectively. In addition, the mean number of bacteria recovered on the control-carriers (T value) was $3.4{\times}10^6$ CFU/mL. In the bactericidal effect of the fumigant, the reduction number of S. typhimurium and E. coli (d value) was 5.26 and 5.64 logCFU/mL, respectively. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. With the results of this study, Fumagari OPP$^{(R)}$ has an effective bactericidal activity, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with pathogenic bacteria.

• Journal of fish pathology
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• v.4 no.2
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• pp.87-94
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• 1991

In the late summer of 1990 and 1991, mass mortality occured among cage-cultured grouper, Epinephelus septemfasciatus in south cost of Korea. The moribund fish didn't feed and became pale or dark chestnut colour and irregularly swimmed due to the loss of equilibrium, finally the diseased fish fell down side away on the bottom or the surface of cage showing the bent of body and died. The diseased fish showed the extensive hemorrahge in brain, the swelling of spleen and bile duct as the specific syptoms of internal organs. So the gill, skin and other organs of the diseased fish were examined for the presence of pathogenic parasites and bacteria. The parasitic Trichodina sp. were detected only from the gill lamella of the diseased fish, but these parasites seemed to be not a direct causative agents that induced the gross mortality of the cultured grouper. because these parasites were also observed in normal grouper, yellowtail, red seabream and rock bream co-cultured with the diseased grouper in same or near cages. In the viral examination, although isolation of the causative agent by the use of estabilshed cell Lines, RTG-2 and CHSE-214, was not succeed, the normal grouper inoculated intramuscularly with the filtered homogenate of the organs of the diseased fish showed the same external and internal signs with the naturally infected grouper. They died within a week. By using the naturally and the artificially infected fishes, electron microscopic observation revealed numerous hexagonal or polygonal particles in the cytoplasm of liver cells. Based on the these results, we suggest that the mass mortality of the cultured grouper would be occurred by the infection of a viral agent.

• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.295-301
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• 2005

About seven hundred bacterial strains were collected from Jeot-Kal, a Korean traditional fermented fishes, in various Korean districts. One of the strains designated JKK238 has its ability to antagonize in vitro the growth of a wide variety of plant pathogenic fungi responsible for diseases of economical importance. The JKK238 strain was isolated from Oh-Jeot, a kind of fermented shrimps, of Kangkyeung in Korea, and was identified as Bacillus subtilis based on its physiological characteristics, fatty acids compositions of cellular wall, and 16S rDNA sequence analysis. We isolated simply antimicrobial lipopeptides (AMLP) by $25\%$ ammonium sulfate precipitation of 3 days-old tryptic soy broth cultures of the JKK238 strain. Further analysis of AMLP revealed that B. subtilis JKK238 produces a wide variety of antifungal lipopeptide isomers from the iturin, fengycin and surfactin families simultaneously. Above results indicate that the JKK238 strain can be added to the limited number B. subtilis strains reported to co-produce the three kinds of lipopeptide families.

• Journal of Food Hygiene and Safety
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• v.31 no.2
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• pp.99-106
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• 2016

This study was aimed to assess microbiological contamination level of Liriope platyphylla farms (A, B, and C) located in Cheongyang, Chungnam province. Specimens sampled from those farms and L. platyphylla tuberous roots were assessed for sanitary indication bacteria such as total aerobic bacteria, coliforms, and Escherichia coli and pathogenic bacteria such as Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus and Bacillus cereus, quantitatively and qualitatively. As a result, those farms are not contaminated by E. coli O157:H7, L. monocytogenes, Salmonella spp., at all. And S. aureus was only found qualitatively from workers' gloves at a farm. As a whole, those farms (soil, harvest container, harvester, cleanser, washing water and tray) were maintained in a low level of microbiological contamination. However a cleanser was contaminated by coliforms ($4.35log\;CFU/100cm^2$), and it is required to improve farm hygiene. Microbiological contamination level of L. platyphylla tuberous root was decreased in the postharvest process including washing and drying.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.275-282
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• 2009

The effect of two plant growth-promoting rhizobacteria (PGPR) on plant growth and systemic protection against soft rot disease and stem rot disease of canola (Brassica napus), caused by Erwinia carotovora and Sclerotinia sclerotiorum was investigated in a laboratory and a greenhouse. Selected PGPR strains C4 and D8 were treated to canola seeds by soaking. Strains C4 and D8 significantly not only increased plant height and root length about 74% and 40.3% and also reduced disease severity of soft rot disease by 80% by C4 and D8 respectively, compared to the control. Especially strain C4 showed antifungal activity against 6 fungal pathogens, S. sclerotiorum, Rhizoctonia solani, Botrytis cinerea, Fusarium oxysporum, Phytophthora capsici and Colletotrichum acutatum. In greenhouse experiment, the seed treatment of both of them increased plant height, leaf width and leaf length of canola plant to 19.5% and 24.9%, 11.3% and 15.3%, and 14.1% and 20.7% by C4 and D8, respectively, and reduced disease severity of S. sclerotiorium. These results indicate that these two PGPR strains can decrease disease severity and increased plant growth under greenhouse condition. Therefore, these two bacteria have a potential in controlling Sclerotinia stem rot of canola. These strains have to investigate under field condition to determine their role of antibiosis, induced systemic resistance and plant growth promotion on canola.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.8-16
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• 2012

The objective of this study was to identify bacterial antagonists of R. solani AG2-2 (IV) on zoysiagrass and to evaluate their antifungal activity in vitro and in vivo to select an antagonistic isolate. Antagonistic isolates that inhibit large patch disease caused by R. solani AG2-2 (IV) in zoysiagrass were selected from several soils, and their antagonistic activities were investigated in vitro and in vivo. Of 216 bacterial isolates, 67 inhibited several plant pathogenic fungi. The isolates that inhibited stem-segment colonization by R. solani AG2-2 (IV) in zoysiagrass were tested in a growth chamber. Eleven isolates were active as plant growth promoting isolates. Among them, five plant growth promoting isolates and their concentration dependent efficiency on zoysiagrass following inoculation with R. solani AG2-2 (IV) was evaluated. Isolate H33 was one of the potential antagonistic isolates, and it was further tested against various plant pathogens. H33 not only suppressed the disease caused by R. solani AG2-2 (IV) on zoysiagrass but also promoted leaf weight and leaf height of zoysiagrass under growth chamber and greenhouse conditions. The H33 isolate, which belongs to Streptomyces arenae, was identified through physiological, biochemical, and 16S rDNA studies. Further studies will investigate the cultural characterization of S. arenae H33 and isolation and identification of antifungal substance produced by S. arenae H33.

• Journal of Life Science
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• v.28 no.4
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• pp.496-507
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• 2018

Immunization has been performed for centuries and is generally accepted as a sustainable method of controlling bacteria, viruses, and mediated and infectious diseases. Despite many studies having been performed on animal subjects to demonstrate the importance of toxin immunity, the use of toxoid vaccines in humans and animals has been limited for a long time. Recently, the development of the toxoid antigen delivery system has been facilitated using novel nano-medicinal technology. The micro/nano-carrier has been used to improve vaccination coverage as well as reduce vaccine costs. A micro/nano-carrier is a micro/nano-sized material that delivers immune cargo, including recombinant or peptide toxoid antigens. These toxoid antigens are either encapsulated in the interior or displayed on the surface of micro/nano-carriers as a way to protect them from the cellular machinery. In particular, the combination of toxoid antigens and micro/nano-carriers can induce phagocytosis through the specific interactions between GCs and macrophages; thus, the toxoid antigens can be delivered easily into the macrophages. This paper reviews recent achievements of micro/nano-carriers in the field of vaccine delivery systems such as microbial ghost cells (GCs, Bacterial ghost cells and Yeast ghost cells), gene-manipulated outer membrane vesicles (OMVs) and biocompatible, polymer-based nanoparticles (NPs, NP-Carrier and NP-Cage). Finally, this review shows various aspects in terms of the hosts' immune responses.

• Journal of Life Science
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• v.18 no.11
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• pp.1606-1611
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• 2008

Outer membrane proteins (OMPs) expressed in the Gram negative bacteria such as Salmonella play multiple functions including material transports, adhesive factors and reception of external signals. This study has been focused on an OmpW protein known as a protein required to form a hydrophobic porin in outer membrane. We have constructed a S. typhimurium CK10 mutant deleting an ompW gene on chromosome. The CK10 strain was more tolerant to SDS than the wild-type strain did. As increase of salt concentration in the culture media, significantly decreased amount of OmpW protein in cells were detected. The maximum OmpW protein was expressed in the absence of salt supplement. However, the growth of CK10 strain was indistinguishable compared to that of the wild-type strain at the variable osmotic conditions. The biological role of differential OmpW expression in response to osmotic conditions remains to be investigated.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.73-78
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• 2002

Bacillus polyfermenticus SCD, which is commonly called as Bisroot strain, is being used for functional foods through the treatment of long-term intestinal disorders, since the live strains in the form of active endospores can successfully reach the target intestine in both humans and animals. The cells of B. polyfermenticus SCD were treated for 24 h in artifical bile after incubation for 2 h in artificial gastric juice and final number of the strain was reached to around $3.3{times}10^7\;CFU/mL$. In test of API ZYM kit, ${\beta}-glucuronidase$ or ${\beta}-glucosidase$ was not produced by B. polyfermenticus SCD. B. polyfermenticus SCD was resistant to antibiotics, such as nisin, streptomycin, tetracycline, and rifamycin. B. polyfermenticus SCD was also affected by alcohol concentration up to 4%, but more than 8%, their growth was not affected significantly. Finally, B. polyfermenticus SCD was shown to inhibit the growth of Listeria monocytogenes ATCC 19111 completely within 24 h of incubation, which indicated its bactericidal nature.