• Journal of fish pathology
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• v.17 no.1
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• pp.39-55
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• 2004

Hundreds of medicinal herbs have been using for the purpose of diseases treatment and immune enhancement for human being and other animals including fishes. Among them, 49 species of medicinal herbs were selected and tested for antibacterial activities against 19 strains of fish pathogenic bacteria in different 4 species. The 49 medicinal herbs were extracted by water and ethyl alcohol. The extracts were freeze dried and some paper discs from the extracts were prepared for the evaluation of antibacterial activity. The tested pathogenic bacteria were 5 strains of Edwardsiella tarda, 5 strains of Vibrio sp., 4 strains of Lactococcus garvieae, 1 strain of Lactococcus raffinose, 1 strain of Streptococcus parauberius, and 3 strains of Streptococcus iniae. The Galla rhois (Obaeja), Gaeonnamu and Hwangleyon showed antibacterial activities on both gram negative and gram positive fish pathogenic bacteria. The Youkgae, Sangbaekpi, Bogolji and Gamcho showed very effective antibacterial activities on gram positive pathogens while Jiyu, Aeyoeb and Yeonkyo showed very effective on gram negative pathogens.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.115-121
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• 2002

To develop a new method of conjugation and to determine the distribution of R plasimds, we isolated multi-drug resistant strains from fish pathogenic bacteria in the farms of south and east seacoasts of Korea. Out of the 134 isolates examined, 10 showed resistance to chloramphenicol, tetracycline, streptomycin, ampicillin, colistin, nalidixic acid, oxolinic acid and kanamycin. One out of 10 multi-drug resistance bacteria, Vibfio damsela JE1 (V. damsela JE1), contained transferable R plasmid of chlorarnphenicol- tetracycline resistance genes and other nucleic acids encoding ampicillin and kanamycin resistance. The presence of the R plasmid was confirmed by conjugation using the chromocult medium (CC) as a selective and differential medium for transconiugants with identification based on the growth or colors of the colonies. The frequency of R plasmid transfer with filter mating method was come out much higher than that of broth mating method and appeared to be dependent upon the mating time and temperature. The optimum conditions for filter mating method were found to be 30$^{\circ}C$ and 24hrs as mating temperature and period, respectively, Moreover, donor cells with R plasmid, both isolate and standard bacteria, were shown to have an ability to transfer the plasmid against Escherichia coli K-12 HB101 (E. coli HB101) and Edwardsiella tarda (E. tarda) RE14 at fairly high frequencies, finally, we isolated 3 isolates of Sphingomonas sp., carrying R plasmid from 12 multi-drug resistant bacteria in normal microflora of the flounder (Paralichthys olivaceus) group used for the isolation of V emsela JE1 four months before. The same size and gene transfer chayateristics of R plasimds with those of V damsela JE1 confirmed that normal microflora have the reservoir activity for R plasmid in natural aquatic environment.

• KSBB Journal
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• v.21 no.1 s.96
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• pp.72-78
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• 2006

This study was carried out to investigate the antimicrobial and antioxidative effects of mycelium cultural extract from mushroom. Mushroom mycelium was grown in a defined synthetic liquid medium and citrus extracts, and the culture extracts were examined for antioxidant and antibacterial activity. Myceliums of Phellinus linteus, Cordyceps militaris, Coriolus versicolor, Sparassic crispa, Agaricus blazei, lnonotus obliquus, Lentinus edodes, Hericium erinacium, Gonoderma lucidium in 10% citrus extract supplemented medium and synthesis medium were incubated in a shaking incubator (120 rpm, $24{\sim}30^{\circ}C$ ) for $7{\sim}15$ days. The antimicrobial activity of the culture fluid of mushroom mycelium grown in submerged liquid culture was tested against 12 microorganisms which were fish pathogens and common bacterial species. The culture extracts showed high activity against Vibrio sp. and had poor effect on Streptocouus sp., S. parauberis, S. iniae. The culture extracts obtained from the synthetic medium showed $30{\sim}93%$ of the 1,1-diphenyl-2-picrylhydrazyl radical scavenger activity, the culture extracts obtained from the citrus extracts medium exhibited antioxidant activity up to 55%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.89-95
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• 2013

Biological and functional characteristics of lactic acid bacteria (LAB) were investigated in mustard stem/leaf kimchi (MK), cabbage kimchi (CK), young radish kimchi (YRK), and cubed radish kimchi (CRK). LAB of young radish kimchi were mainly composed of bacilli in contrast to the other kimchi. 89.2% LAB isolated from all kimchi harbored plasmids. However, LAB had an average of $4.1{\pm}0.5$ plasmid bands in YRK, more than MK, CK, and CRK. Exopolysaccharides were produced by 10.9~11.1% of LAB, and were especially by LAB isolated from radish kimchi. A significant percentage of LAB (69.5%) had antibacterial activity against one sensitive strain or more. LAB from CK, YRK and CRK had antimicrobial activities against Bacillus sp., Listeria monocytogenes, and Salmonella Typhimurium, while the LAB from MK had activities against Vibrio parahaemolyticus higher than those from the other kimchi. In YRK and CRK, acid-tolerant LAB were twice as prevalent as those in MK and CK. Bile-tolerant LAB isolated from CRK were more prevalent than other kimchi. When $10^8$ CFU of LAB were added to Caco-2 cells, 12.1% of LAB isolated from all kimchi showed similar adherent activity to Lactobacillus rhamnosus GG. LAB of MK particularly adhered to Caco-2 cells, 2.0~4.1 fold higher than LAB in the other kimchi. From these results, biological and functional characteristics of LAB varied according to the type of kimchi and LAB existing in kimchi were limited to their respective species.

• Journal of fish pathology
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• v.20 no.1
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• pp.41-47
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• 2007

To investigate the cause of the mass mortality during rockbream, Oplegnathus fasciatus seed production, the water quality and bacterial counts of sea water in breeding tanks was measured 20days post the hatch. During breeding of rockbream fry, the environmental factors of water quality were detected as pH, ammonia COD, phosphate at the supply of the food organisms and the seawater. pH was decreased from the 8.21 of the 1 day per hatch (dph) to 7.56 of the on the 7 dph. Ammonia was conversely increased 0.49 ppm of the 1 dph to 0.85 ppm of 10 dph. As the adding of the chlorella and the rotifer tanks, COD was increased the 3.3 times and 1.2 times than those of pre-adding respectively. The phosphate and the ammonia were also increased 1.7 and 2.3 times, with adding the chlorella respectively, which exceeded the second grade for sea water evaluation level, 0.015 ppm and 0.1 ppm respectively. Water quality was not improved by PSB (Photosynthetic Bacteria) treatment, which increased the value of COD in 1.7 times, phosphate in 2.7 times and ammonia in 1.4 times. The number of the bacteria was also increased along the dph. According to the treatment of chlorella, the number of total bacteria increased in 1.4 times and those of Vibrio sp. 1.6 times. The lethal concentration of ammonia was investigated that over than 10 ppm could killed the fry of rockbream within 28 hrs, but 40% in 2 ppm.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.35-41
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• 2006

Antibacterial activities of the trace elements in combination with the food additives were measured against 6 kinds of food-borne microorganisms such as Escherichia coli, Vibrio parahaemolyticus, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Pseudomonas fluorescens. The difference of antibacterial activity was not shown among the kinds of food additives, such as dextrin, gelatin and collagen. Zn and Ge in combination with food additives had strong antibacterial effect. Especially, $1\%$ zinc acetate in combination with $1\%$ gelatin was more effective against P. fluorescens and S. aureus than against Bacillus sp., E. coli and V. parahaemolyticus. Minimum inhibitory concentration of zinc acetate in combination with $1\%$ gelatin appeared to be 0.5 mg/mL on S. aureus and P. fluorescens, and 1.0 mg/mL on E. coli, V. parahaemolyticus, B. cereus and B. subtilis. Minimum bactericidal concentration of zinc acetate in combination with $1\%$ gelatin appeared to be 0.5 mg/mL on P. fluorescens and 1.0 mg/mL on E. coli, V. parahaemolyticus, S. aureus, B. cereus and B. subtilis. The zinc acetate in combination with gelatin showed stronger inhibitory effect in acidic range below pH 6.0, and remained active even after heat treatment at $121^{\circ}C$ for 15 min. In comparison with control, the viable cell counts of fish pastes, which were coated with the solution containing both $1\%$ zinc acetate and $3\%$ gelatin, were decreased by more than 100-fold until the storage of 7 days at $10^{\circ}C$. The results indicate that the combined use of zinc acetate and some food additives could prolong the shelf life of fish pastes by 8 days or more at $10^{\circ}C$.