• Fisheries and Aquatic Sciences
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• v.23 no.8
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• pp.20.1-20.18
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• 2020

Background: Olive flounder, Paralichthys olivaceus, is an economically important aquaculture species in Korea. Olive flounders have been heavily damaged by streptococcal infections every year and are treated with antibiotics. However, antibiotic abuse is causing the emergence of resistant strains, and to overcome this, research has shown that new antibiotics must be applied. Tylosin is a relatively safe antibiotic and has good activity against Gram-positive bacteria and mycoplasma. We studied the therapeutic effects and side effects of tylosin on Streptococcus parauberis-infected olive flounder. Methods: After artificial infection of olive flounder with S. parauberis SPOF18J3, an appropriate dose of tylosin was confirmed by intramuscular injection (I.M.) at 2.5, 5, 10, and 15 mg/kg, and oral administration at 10 and 20 mg/kg. After I.M. and oral administration dosing of tylosin, side effects were confirmed by serological analysis, histopathological analysis, and median lethal dose (LD₅₀) analysis at both an appropriate concentration and a high concentration. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's test (p < 0.05). Results: The appropriate I.M. and oral administration concentration of tylosin administered to olive flounder infected with S. parauberis SPOF18J3 was found to be 10 mg/kg. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were showed not significantly different between the control group and the experimental groups. The histopathologic results showed mild inflammatory responses in muscle and tubular vacuolization and tubular atrophy appeared, but there were no significant differences between the groups. The LD₅₀ was confirmed to be 461 mg/kg. Conclusion: In this study, an effective treatment method was provided by verifying the treatment effects and side effects of tylosin in olive flounder infected with S. parauberis, which can be applied directly to aquaculture sites. In addition, these results may be used as a reference for evaluation required upon request to obtain approval for tylosin antibiotics as fishery antibiotics in Korea. After approval, it is possible that a fishery disease manager will be able to prescribe and sell the antibiotic tylosin.

• Journal of fish pathology
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• v.37 no.1
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• pp.61-69
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• 2024

In this study, bacterial disease monitoring was conducted from July to November 2022 for three representative bacterial species (Streptococcus parauberis, Vibrio spp. and Edwardsiella piscicida) to investigate the occurrence of bacterial diseases in farmed olive flounder (Paralichthys olivaceus) on Jeju. Over a period of five months, 3,146 olive flounders were tested. The average length and weight of the olive flounder that were sampled for the disease were found to be 32.1 cm and 357.9 g, respectively. Bacteria were detected in 1,228 olive flounders, of which 24.6% were identified as Vibrio spp.. S. parauberis and E. piscicida were identified in 6.3% and 3.2% respectively, and 3% were unknown strains that could not be identified. Also, 41 (1.3%) olive flounders were found to have both S. parauberis and Vibrio spp. and 23 (0.7%) olive flounders were found to have both E. piscicida and Vibrio spp.. In particular, S. parauberis, Vibrio spp. (V. scophthalmi) and E. piscicida were detected simultaneously in one olive flounder. In fish infected with E. piscicida, the most obvious external signs were hernias and ascites.

• Journal of Life Science
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• v.30 no.7
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• pp.606-613
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• 2020

This study investigated the effect of olive oil substitution ratio on physicochemical quality of pork patty. Five treatments were performed as follows: control (T0, 20% pork fat), T1 (pork fat 15% and olive oil gel 5%), T2 (pork fat 10% and olive oil gel 10%), T3 (pork fat 5% and olive oil gel 15%), and T4 (olive oil gel 20%). The moisture increased and fat amount was decreased in proportion to olive oil substitution ratio. The L^* and a^* values were highest levels in raw and cooked pork patty of T0, and the b^* value was highly enhanced in of cooked pork patty of T4. The water holding capacity, moisture and fat retention were significantly increased, and the cooking loss, diameter reduction and shrinkage ratio were decreased by olive oil substitution ratio. The hardness, springiness and chewiness showed the highest level in T4, and the cohesiveness and gumminess were highest in T0. The reduction ratio of cholesterol in T1, T2, T3 and T4 were 13.8%, 21.6%, 34.5% and 49.0%, respectively, indicating that the content was lowest level in T4. The palmitic acid was the most abundant saturated fatty acid, and the oleic acid was the most abundant unsaturated fatty acid. The unsaturated fatty acid of pork patty was increased in proportion to olive oil substitution ratio. Therefore, the olive oil gel substitution of low-fat pork patty results in a positive effect on the physicochemical qualities due to reduced cholesterol and saturated fatty acids.

• Journal of fish pathology
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• v.16 no.2
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• pp.103-110
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• 2003

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.805-809
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• 2006

Ozonized olive oil was tested for its mutagenic potential in a Salmonella/microsome assay. Additionally, antimicrobial activity was tested against Propionibacterium acnes, Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa, pathogenic strains related to acne, using the paper disk and agar dilution method. Ozonized olive oil showed antimicrobial activities against all the strains tested, with minimal inhibitory concentrations (MICs) values in a range of 2${\sim}$10 mg/mL. Mutagenicity of ozonized olive oil was evaluated with Salmonells typhimurium TA98, TA100 and Ta1535, with and without addition of S9 mixture. No increase in the number of $his^{+}$ revertants over the negative control (solvent and non-ozonized olive oil) values was observed with TA98 (1,000 ${\mu}g/plate$), TA100 (1,500 ${\mu}g/plate$) and TA1535 (1,500 ${\mu}g/plate$) strains. The results from this study suggested that ozonized olive oil does not show any mutagenic potential.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.353-358
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• 1999

This study is to find out the effects of various iron concentrations on growth, feeding and feed efficiency of olive flounder, Paralichthys olivaceus, The growth rate, feeding rate and feed efficiency of olive flounder in each experiments were represented by the relative value. The relative growth rate and relative feed efficiency of olive flounder were kept almost constant below the iron concentration of 1.0 mg/$\ell$, but were significantly decreased above the 5,0 mg/$\ell$ iron concentration. The growth rate, feeding rate and feed efficiency of olive flounder exposed to 10.0mg/$\ell$ iron concentration were significantly decreased than that exposed to normal condition. From these results, it could be concluded that the high level of 5.0 mg/$\ell$ iron concentration in the bottom water would curtail production of olive flounder in coastal area.

• Journal of Life Science
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• v.26 no.12
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• pp.1470-1476
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• 2016

The viral hemorrhagic septicemia virus (VHSV), which belongs to the Novirhabdovirus genus of the Rhabdoviridae family, is a viral pathogen that causes severe losses in the olive flounder farming industry. Among six encoding VHSV proteins, the non-virion (NV) protein has been shown to have an impact on virulence. In our previous studies, transcriptomics microarray analysis by using VHSV-infected olive flounder showed that VHSV infection significantly down-regulated the mRNA expression of glycolytic enzymes. In addition, VHSV NV protein variants decreased the intracellular ATP level. Based on these results, we have tried to examine the effect of VHSV NV protein on glycolytic enzyme glucokinase expression, which phosphorylates glucose to glucose 6-phosphate. Our results indicated that the NV protein significantly decreased the mRNA expression of glucokinase in olive flounder HINAE cells. Furthermore, the NV protein played a negative role in the promoter activation of glucokinase. Furthermore, glucose uptake was effectively inhibited by VHSV infection and NV protein expression in olive flounder HINAE cells. These results suggest that the VHSV NV protein negatively regulates glycolytic enzyme expression by a transcription level and eventually leads to gradual morbidity of olive flounder through cellular energy deprivation. The present results may be useful for the prevention and diagnosis of VHSV infection in olive flounder.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.303-309
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• 2005

Olive flounder (Paralichthys olivaceus) is the major mariculture fish in Korea. The annual aquaculture production of olive flounder in Korea during the period of 2003 was 300,000 ton (2002 Statistics, Ministry of Maritime Affairs & Fisheries, Korea Government). Anesthetics is very necessary in aquaculture to minimize stress and damage during harvesting, grading, transportation, spawning induction and handling to fish. In the present study, isoeugenol as new anesthetic in marine fish, especially olive flounder, was examined to know the efficacy and proper concentration. As a result, olive flounder adult was exhibited sedation at 5 ppm at 10 and $15^{\circ}C$, and 7.5 ppm at $20^{\circ}C$, respectively. Anesthesia was required at least 10, 7.5 and 10 ppm at $10^{\circ}C$, $15^{\circ}C$ and at $20^{\circ}C$, respectively. In case of fry, the effect of sedation was observed from 2.5 ppm at $10^{\circ}C$ and 5 ppm at 15 and $20^{\circ}C$, respectively. Anesthesia was observed from 2.5 ppm at $10^{\circ}C$, 5 ppm at 15 and $20^{\circ}C$, respectively. In acute toxicity test, it was impossible to explore $LD_{50}$ with the concentration of isoeugenol adult at $15^{\circ}C$ used, but over immersion volume of 15 ppm at $15^{\circ}C$ was observed mortality in fry. Based on the present study, isoeugenol was identified as a safe and active anesthetic to olive flounder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1405-1411
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• 2006

The presence and content of residual hexane in the olive oils were studied. Total 41 olive oils of imported and domestic brands, which were labeled as extra virgin and refined (mixed), were collected from the market. For analysis, electronic nose and headspace SPME-GC/MS were used. Electronic nose equipped with 12 metal oxide sensors was used for the discrimination of odor pattern of olive oils against the different concentrations of hexane. From the results, it is assumed that the contents of residual hexane in the collected olive oils were below 5 ppm. For Qualitative and quantitative analysis of hexane, polydimethylsiloxane (PDMS) fiber was employed for SPME-GC/MS. In the results, the peak of residual hexane was detected in 8 samples from 41 olive oils. But the detected level was no more than 1 ppm that is under the regulation limit (5 ppm) by Korea Food Additive Code.

• Journal of Life Science
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• v.20 no.5
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• pp.662-669
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• 2010

Lipolytic enzyme-producing bacteria were isolated from edible oil mill effluents on tributyrin agar medium. The shake-flask-scale studies yielded a promising isolate and it was identified as Pseudomonas sp. An OME using various microbiological observations such as cultural, microscopic, and biochemical tests was undertaken and confirmed using PIBWIN bacterial identification software. Lipolytic enzyme production was screened with oils such as sunflower, caster, coconut, tributyrin, and olive. Amongst these, olive oil showed an increased lipase production 6.1 U/ml. In view of the highest lipolytic enzyme production with olive oil, further optimizations were carried out using olive oil as a carbon source. Lipolytic enzyme production was optimized by a conventional 'one variable at a time' approach and the significant factors were further analyzed statistically using response surface methodology (RSM). The effect of physical factors such as incubation time, temperature, initial medium pH, and nutritional factors such as concentration of olive oil and yeast extract were examined for lipase production. Lipolytic enzyme secretion was strongly affected by three variables (incubation time, concentration of yeast extract and olive oil). Therefore, the interaction of these three factors was further optimized using response surface methodology. The optimized conditions of lipase production using response surface methodology yielded a maximum of 9.62 U/ml with optimum conditions for incubation, yeast extract and olive oil concentrations were found to be 48 hr, 0.3 g. and 0.9 ml. respectively.