• 현장농수산연구지
• /
• 제23권1호
• /
• pp.81-87
• /
• 2021

2020년 11월, 국내의 넙치 양식장에서 양식 중이던 넙치가 이상 유영 소견을 보이다가, 지속적으로 폐사하였다. 질병 진단 과정 중, 폐사어의 신장에서 세균(KNCFKW-PN1)이 분리되었다. gyrase B subunit 유전자의 시퀀스 분석 결과, KNCFKW-PN1 분리주는 기존에 보고된 LMG 2227^T 균주의 해당 유전자 시퀀스와 99.59% 유사도를 보여 Pseudoalteromonas nigrifaciens 로 동정이 되었다. 항생제 감수성 실험 결과에 따르면, KNCFKW-PN1 분리주는 ciprofloxacin에 대하여 중등도의 내성을 나타내었고, ampicillin, cefepime, cefotaxime, ceftazidime, amikacin에 내성을 나타내었다. 본 사례는 다제 내성 Pseudoalteromonas nigrifaciens 세균이 넙치로부터 분리된 최고의 보고이다.

• 한국어병학회지
• /
• 제35권2호
• /
• pp.225-230
• /
• 2022

Viral hemorrhagic septicemia (VHS) is one of the most serious viral diseases affecting farmed olive flounder (Paralichthys olivaceus) in Asian countries. VHS, caused by viral hemorrhagic septicemia virus (VHSV), occurs in over 80 different cultured and wild fish species worldwide. Our previous study demonstrated that VHSV infection can be restricted by adjusting the water temperature to over 17℃ from the host optima. We confirmed that the effective VHSV immersion vaccine treatment was a tissue culture infection dose (TCID) of 10^5.5 TCID₅₀/mL at 17℃. However, the safety of live VHSV immersion vaccines remains unclear. The objectives of this study were to 1) demonstrate the safety of the live VHSV immersion vaccine under co-habitant conditions and 2) estimate the pathogenicity of VHSV in live VHSV-vaccinated flounder at 10℃. No mortality was observed in olive flounder treated with the live VHSV immersion vaccine, and the vaccinated flounder challenged with VHSV did not transfer VHSV to naïve fish at 10℃ through cohabitation. VHSV titration was below the detection limit (< 1.3 log TCID₅₀/mL) in live VHSV immersion vaccine-treated flounder challenged with VHSV at 10℃. This study demonstrated that flounder treated with the live VHSV immersion vaccine were resistant to VHSV infection, and the live vaccine was also safe for naïve fish even at a water temperature known to be VHS infectious.

• 한국해양생명과학회지
• /
• 제2권1호
• /
• pp.12-19
• /
• 2017

급격한 수온의 변화는 어류의 생리학적인 측면에서 스트레스를 유발한다. 본 연구에서는 넙치(Paralichthys olivaceus)로부터 각 수온별(9, 12, 15, 18 및 21℃) 조건에 따라 24 및 48시간 동안 노출시킨 후에, 혈액생리학적 분석, 스트레스 단백질로 알려진 Hsp70 mRNA 발현 및 산소 소비량을 조사하였다. 혈액학적 분석에서 hematocrit (Ht) 및 hemoglobin (Hb), 혈장 코티졸 및 글루코스의 변화, aspartate aminotransferase (AST) 및 alanine aminotransferase (ALT), NH₃, 삼투질농도(osmolality) 및 총단백질(total protein, TP)은 9℃ 및 12℃에서 다른 수온별 실험구에 비해 대부분의 항목에서 유의적인 차이를 보였다. Hsp70 mRNA 발현은 9℃ 및 12℃에서 다른 실험구에 비해 높은 발현량을 확인하였고, 산소소비량은 9℃ 및 12℃에서 21℃에 비해 낮았다. 이러한 결과는 넙치 종자의 장거리 수송을 위한 수온자료로 활용할 수 있다.

• Journal of Microbiology and Biotechnology
• /
• 제33권10호
• /
• pp.1390-1401
• /
• 2023

In this study, a 12-week feeding experiment was conducted to characterize the effects of exogenous α-amylase on the growth, feed utilization, digestibility, plasma α-amylase activity, feed degradation rate, and fecal particle size of olive flounder (Paralichthys olivaceus). Diet was supplemented with 0 (AA₀; control), 100 (AA₁₀₀), 200 (AA₂₀₀), or 400 (AA₄₀₀) mg/kg of α-amylase, respectively. Fish (273.1 ± 2.3 g) were stocked into 12 tanks (25 fish/1,000-L tank) and 3 tanks were randomly selected for each diet group. As a result, α-amylase was found to have no significant effects (p ≥ 0.05) on the growth, feed utilization parameters, and whole-body proximate compositions. α-Amylase-treated fish exhibited only a significant increase in the apparent digestibility coefficient of carbohydrates compared to the controls. In addition, in vitro analyses revealed that α-amylase dose-dependently increased (p < 0.05) the feed degradation rate, while photographs of the intestinal content after 2, 4, and 8 h of feeding demonstrated an improved degradation rate in the α-amylase-treated groups. Plasma α-amylase content was higher in the AA₂₀₀ and AA₄₀₀ groups, whereas the control group produced significantly larger-sized fecal particles (90% size class) than these two groups. In the intestine, no changes were observed in the expression levels of the immune-related TNF-α, IL-1β, IL-2, immunoglobulin-M, HSP-70, lysozyme, and amylase alpha-2A. However, growth-related genes IGF-1, IGF-2, TGF-β3, and growth hormone genes were upregulated in muscle tissues. Collectively, exogenous α-amylase has positive roles in the modulation of the digestibility coefficient, blood α-amylase concentration, growth-related gene expression, and diet degradation for improved digestion in olive flounder.

• 한국수산과학회지
• /
• 제57권1호
• /
• pp.23-31
• /
• 2024

This study evaluated the utilization of a low fish meal (LFM) diet and black soldier fly (BSF) Hermetia illucens meal and oil as a fish meal (FM) substitute or functional additive for juvenile olive flounder Paralichthys olivaceus at the Jeju fish farm. Two experimental diets replaced FM using animal (tankage, poultry byproduct and tuna byproduct meal) and plant (wheat gluten and soy protein concentrate) protein sources, containing 45% (FM45) and 35% (FM35) of FM, respectively. One experimental diet replaced FM with animal, plant, and BSF meal, fish oil using insect meal and oil (FM35+). After the feeding trial ended, no differences in growth performance, feed utilization, survival and biological indices were observed among all experimental groups. Aspartate aminotransferase and cholesterol levels in the FM35 and FM35+ groups were significantly higher than that in the FM70 group. The linoleic acid level in the muscle was significantly higher in the fish fed with the FM70 diet than in those fed with the FM45, FM35, and FM35+ diets. Thus, the LFM diet is suitable for juvenile olive flounder farming during six months.

• 수산해양교육연구
• /
• 제27권4호
• /
• pp.1084-1091
• /
• 2015

5겹 편뜨기한 넙치 육 50 g을 chopper로 마쇄한 후 계란 흰자, 생크림, 레몬즙, 브랜디, 소금 및 후추를 첨가하여 반죽하였다. 랩 위에 평평하게 편 반죽(25 g) 위에 치즈(4 g)를 올리고 다시 반죽(25 g)을 덮은 후 랩으로 돌돌 말고 호일로 감싸서 끓는 물에 5분간 익혀 폴리에틸렌 필름($20{\times}30{\times}0.05mm$)에 진공 포장한 제품을 Terrine-1, 끓는 물에 익히지 않고 바로 진공 포장한 제품을 Terrine-2로 하였다. 동결 상태의 Terrine-1을 전자레인지로 해동하고 데운(2분간) Sample-1과 동결상태의 Terrine-2를 해동한 후 끓는 물에 5분간 익힌 Sample-2의 이화학적 성질과 관능적 특성에 대하여 살펴보았다. Sample-1과 Sample-2 모두 생균수가 검출되지 않았으며, 일반성분의 경우 수분함량은 각각 31.0 및 30.4%, 조단백질은 각각 17.7 및 18.6%, 조지방은 두 시료 모두 8.3%, 조회분은 각각 1.4 및 1.5%로 거의 차이가 없었다. pH는 각각 6.48 및 6.37로 거의 차이가 없었다. 조직감의 경우 Sample-1이 $16.67g/cm^2$, Sample-2가 $23.00g/cm^2$으로 Sample-2가 더 높은 값이었다. Sample-1과 Sample-2의 TBA 값은 큰 차이가 없었다. Sample-1과 Sample-2의 총유리아미노산 함량은 각각 2050.5 및 2065.2 mg/100 g으로 비슷하였으며, 두 시료 모두에서 glutamic acid가 16.6%로 가장 많은 함량이었으며, 다음으로 lysine, leucine 및 aspartic acid 순이었다. 관능검사 결과 Sample-2의 관능적 기호도가 Sample-1보다 조금 높았다.

• Fisheries and Aquatic Sciences
• /
• 제5권1호
• /
• pp.28-31
• /
• 2002

Effects of cimetidine, a cytochrome P450 inhibitor, on the benzo[a]pyrene (BaP)-mediated cytochrome P450 induction and lipid peroxidation of liver in olive flounder, Paralichthys olivaceus, were investigated. Fish were fed either a cimetidine-supplemented diet or a cimetidine-free control diet once daily to satiation for 3 days. After 6 hrs of last feeding, the fish received intraperitoneal (i.p.) injection of BaP (20 mg/kg of body weight) dissolved in sterile corn oil $(100 \mu L)$ or received only a corn oil i.p. injection. At 1, 2, 3, and 7 days after the injection, hepatic cytochrome P450 and thiobarbituric acid reactive substances (TBARS), an indicator of lipid peroxidation, were analyzed. BaP injection resulted in an increase of hepatic cytochrome P450, and the fish fed the cimetidine-supplemented diet before injection of BaP showed delayed increase of hepatic cytochrome P450 compared to the fish fed a cimetidine-free diet and BaP injected. Injection of BaP clearly induced hepatic lipid peroxidation, and consistently higher TBAR values were shown in the fish fed a cimetidine­supplemented diet before injection of BaP than the fish injected with BaP alone.

• Fisheries and Aquatic Sciences
• /
• 제5권1호
• /
• pp.1-4
• /
• 2002

The modulatory effects of oxytetracycline treatments at high concentrations on the infection potential of scuticociliates in cultured juvenile olive flounder (Paralichthys olivaceus) and density of the ciliates in culturing water were investigated. The groups bathed with 400 and 500 ppm of oxytetracycline showed significantly lower intensities of scuticociliates on the fish and considerably lower number of the ciliates in culturing water when compared with the control group. However, the intensity of scuticociliates on the fish in the group bathed with 300 ppm of oxytetracycline was not significantly different with that of the control group in spite of considerably lower number of scuticociliates in culturing water than in that of the control group. Although the intensities of scuticociliates on the fish intubated orally with 400 and 500 mg/kg of oxytetracycline were lower than that of the control group, there were no statistical significances. In contrast, the fish fed 300 mg/kg of oxytetracycline showed significantly lower intensity of scuticociliates when compared with other groups. The results of this study suggest that oxytetracycline treatments can modulate occurrence of scuticociliatosis in fish farms probably through change of bacterial density, damaging to scuticociliatosis and immuno-suppression of fish.

• 한국양식학회:학술대회논문집
• /
• 한국양식학회 2003년도 추계학술발표대회 논문요약집
• /
• pp.76-77
• /
• 2003

Olive flounder Paralichthys olivaceus larvae and early juveniles were reared for 43 days after hatching in order to observe the effects of starvation during development and metamorphosis. Morphological, histological and biochemical measurements were made to assess the nutritional condition during growth and starvation from pre-matamorphic through post-metamorphic phases. Two groups of fish were compared ; one with sufficient food supply and one under continuous starvation until death. Among morphometric analyses, both ratios of body height at anus/head height and pre-/post-anal lengths appeared to be sensitive to starvation during which substantial reduction was observed within a day of food deprivation. Histological variables as intestinal and rectal epithelial heights and gall bladder volume changed significantly with onset of starvation. The gut epithelial heights of starving fish decreased with advances in starvation, although they fluctuated during mid-metamorphic phase. In contrast, gall bladder volume increased remarkably soon after starvation. Ontogenetic changes in both gut epithelial height and gall bladder volume were evident, those associated with settlement and/or completion of metamorphosis. Abrupt decrease in the RNA/DNA ratios of starving fish were found right after onset of starvation. Even in the fed fish marked fluctuations in its ratios during metamorphosis were observed, evident by decreasing from late-metamorphic to post-metamorphic stages. These findings suggest that a combination of morphologically and histologically sensitive characteristics, and biochemical measurement could be utilized as a measure to evaluate nutritional condition related to starvation in wild olive flounder larvae and juveniles.

• Animal cells and systems
• /
• 제14권1호
• /
• pp.25-30
• /
• 2010

We employed a new and improved differential display reverse transcription-polymerase chain reaction (DDRT-PCR) method, which involves annealing control primers (ACPs), to identify the genes that are specifically or prominently expressed in olive flounder (Paralichthys olivaceus) juveniles (35 days post-hatch; dph) compared to larval-stage (dph 21) flounder. Using 60 ACPs, we identified eight differentially expressed genes (DEGs) and basic local alignment search tool (BLAST) searches revealed eight known genes. Gene expression levels were confirmed by RT-PCR. Phosphoglucose isomerase (PGI) was highly expressed at 21 dph, while nephrosin, myosin light chain (MLC), myosin heavy chain (MHC), carboxypeptidase A, chymotrypsin B, fish-egg protein, and matrix protein were expressed at 35 dph. PGI, MLC, and MHC expression was further analyzed by RT-PCR. The differentially expressed genes identified in this study may provide insights into the molecular basis of development in olive flounder.