• Journal of fish pathology
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• v.14 no.1
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• pp.3-10
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• 2001

The present study was to obtain a basic research data about medicinal herbs by screening in vitro antimicrobial activity and the production of superoxide anion($O_2^-$) from the head kidney phagocytes of olive flounder, Paralichthys olivaceus. The following fourteen kinds of medicinal herbs extracted by boiling water were used : Gosam, Gwijeonu, Gujeolcho, Bagha, Bangpung, Yeongyo, Yagssug, Jiyu, Sambaegcho, Samjiguyeobcho, Sangbaegpi, Sohwehyang, Pyeonchug, Palgag. Antimicrobial activity against fish pathogenic bacteria, Listonella anguillarum, Vibrio sp., Vibrio alginolyticus, Edwardsiella tarda, Streptococcus sp. and Lactococcus garvieae, and the production of superoxide in kidney macrophage of olive flounder were examined by disk method and nitroblue tetrazolium(NBT) reaction, respectively. Among the tested herbs, Yagssug showed the highest antimicrobial activity against those fish pathogenic bacteria and stimulation of $O_2^-$ production.

• Journal of Life Science
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• v.6 no.3
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• pp.198-203
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• 1996

A thermolabile alkaline phosphatase has been purified through steps of osmotic shock, ammonium sulfate salting-out, and DAEA-cellulose chromatography from the cultured broth of the marine Vibrio sp. M-96 strain. The optimal temperature for the enzyme activity was 35$\circ$C. The optimal pH was pH11.0, and the range of pHstability was pH10.4 to 12.0. Thermal inactivation occured within 6 mintes at 60$\circ$C. The enzyme was considerably inactivated by 0.1mM concentrations of Hg$^{2+}$, Ni$^{2+}$ and Zn$^{2+}$, whereas activated up to 234% by 1mM of Mn$^{2+}$. The activation energy and deactivation energy by the Arrhenius equation were 4.02 Kcal/mol and 9.098 Kcal/mol, respectively. The Km and Vmax values of the enzyme for p-introphenylphosphate were found to be 0.0465mM and 0.001334mM/min, respectively. Active form of the enzyme had a molecular weight of 57,000 dalton determined by the Sephadex G-200 gel filtration method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.557-562
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• 1985

Moderately halophilic bacteria were collected from solar salt with Larsen medium containing $10\%$ NaCl. A total of 56 strains were isolated and tested for the presence of plasmid DNA by agarose gel electrophoresis. Twelve isolates ($21\%$) carried at least one kind of plasmid. Six different isolates among them were selected to study the molecular weight of plasmids and the morphological and physiological characters. Vibrio sp. 14, Alcaligenes sp. 63, Pseudomonas sp. 11, Flavobacterium sp. 38, Bacillus sp. 16, and Alcaligenes sp. 52 carried at least one plasmid of about 7.2 kbp, 6.4 kbp, 6.85 kbp, 8.5 kbp, 8.75 kbp, and 6.8 kbp respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.147-154
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• 1986

Vibriosis has caused severe losses among cultured yellowtail (Seriola quinquerediata) at some cage farms in Korea in recent years. Major object of this study was to investigate the causative organism of the diseased cultured yellowtail. The samples were collected from the aquarium of Fisheries Research & Development Agency during the period from November 1984 to January 1985. The experimental results are summarized as follows ; Among the isolated bacteria from the diseased yellowtail, Vibrio sp. isolated from the kidney was considered to he the causative organism. Tetracycline, chloramphenicol and gentamycin were observed as bacteriostatic agents to the pathogenic strain, but sulfisomezole and sulfisoxasole were not. When the isolated strain was injected intramuscularly to yellowtail, rid sea-bream, rock-bream and common carp, it had virulence at $25^{\circ}C$ to all fish examined but to virulence at $15^{\circ}C$ except for yellowtail.

• Microbiology and Biotechnology Letters
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• v.23 no.4
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• pp.432-438
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• 1995

The intracellular alginase from Vibrio sp. AL-145 was purified by ion chromatography on DEAE-Cellulose column, Q-Sepharose column, and gel filtration on Sephadex G-100 column. The optimum pH and temperature for the activity of the purified intracellular enzyme were 8.0 and 37$\circ$C, respectively. The enzyme was stable at the pH range of 7.5-8.5, and at 30$\circ$C for 30 min. The molecular weight of the intracellular enzyme was estimated to be about 23, 000 daltons by SDS-polyacrylamide gel electrophoresis. NaCl was required for enzyme activity and the optimum concentration was 0.5 M. The activity of intracellular enzyme was inhibited by Co$^{2+}$, Hg$^{2+}$, Zn$^{2+}$, 0-phenanthroline, $\rho$-CMB, EDTA and iodoacetate, and stimulated by Ca$^{2+}$, L-cysteine and 2-mercaptoethanol. This enzyme was an alginase specifically degrading alginic acid.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.106-106
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• 2016

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.236-243
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• 2004

Antimicrobial effect of chitosan and its oligosaccharides was examined on Vibrios sp., Edwardsiella tarda and Streptococcus sp., which are major pathogenic bacteria inducing bacterial diseases of acquacultured flounder. Chitosan oligosaccharides (COS ) were produced by enzymatic hydrolysis of chitosan in an ultrafiltration mombrane bioreactor system which was established with three membranes with different molecular weight cut-off (MWCO) 1,000, 5,000 and 10,000, and fractionated into three kinds of COS, based on their molecular weight sizes. The three kinds of COS were as follows : relatively high molecular weight COS [HMW-COS, molecular weight distribution of 7,000 to 24,000 Da〕, medium molecular weight COS 〔MMW-COS, 1,500 to 6,000 Da〕, and low molecular weight COS 〔LMW-COS, 1,000 to 1,500 Da). Chitosan and HMW-COS effectively inhibited the growths of Vibrio sp. and Streptococcus sp. and their antimicrobial activities were superior to the others with smaller molecular weights. This result suggested that antimicrobial effect of chitosan preparations extremely depend on their molecular weight sizes. Antimicrobial effect of chitosan and HMW-COS on E. tarda was improved by longer inoculation times. Scanning electron microscopy in morphological change of E. tarda treated with chitosan preparations showed that chitosan and HMW-COS bound to the cells and suppressed the growth of the cells. This observation appears to prove the fact that positive charged amines of chitosan electrostatically bind to negative charged compounds of cell walls.

• Journal of Microbiology
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• v.38 no.4
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• pp.224-229
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• 2000

Chitin-degrading marine bacterial strain 98CJ11027 was isolated from bryozoa from the coastal area of Cheju Island, Korea, and identified as a member of the genus Vibrio. The molecular mass of the main extracellular chitinase (chitinase I), purified from strain 98CJ11027, was estimated to be 98 kDa. The optimal condition for chitinase I activity is pH 6.0 and 45$^{\circ}C$. The activity was inhibited by Fe$\^$+2/ and Cu$\^$+2/. Chitinase I displayed the hydrolysis type of chitobiosidase and catalyzed reversed hydrolysis leading to the synthesis of tetraacetylchitotetraose.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.302-304
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• 2018

We, for the first time, isolated and identified a Vibrio splendidus KCTC 11899BP producing hyaluronate lyase from seawater. This enzyme is produced only when hyaluronic acid (HA) is added to the basal medium. Hyaluronate lyases are produced by microorganisms, which degrade the ${\beta}$-(1, 4) bond of HA to produce disaccharide. The genome of KCTC 11899BP, which consist of two circular contigs that are 3,522 kb (contig 1) long and 1,986 kb (contig 2) long respectively, as like other Vibrio sp. that contained 2 chromosomes. The genome included 4,700 predicted open reading frames, G + C content 44.12%, 137 tRNA genes, and 46 rRNA genes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.139-143
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• 1999

The antimicrobial action of bacteriocin produced by lactobacillus sp. GM7311 against three Gram negative bacteria, Proteus mirabilis, Vibrio parahaemolyticus, and Escherichia coli, was investigated, When the bacteriocin was added to the culture at different stages, viable cells of all of the indicator strains tested were decreased, even though the most inhibited indicator cell growth stages were different. Transmission electron microscopic observation of indicator strains treated with bacteriocin revealed cell Iysis, indicating the cell membrane appears to be the primary site of action. The amino acids concentration of indicator strains treated with bacteriocin were diminished and fatty acids compositions were changed as compared with controls.