• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.271-280
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• 2010

Vibrio alginolyticus, a Gram-negative marine bacterium, is one of the causative agents of fish vibriosis. Its virulence factors and pathogenesis mechanism are barely known, except for some extracellular products (ECPs) that are known to be regulated by quorum sensing system. Therefore, the present study used a microarray to analyze the transcription profiles of the wild-type V. alginolyticus and a deletion mutant of luxO, the pivotal regulator in Vibrio quorum sensing systems, which resulted in the identification of a putative virulence factor, MviN. Quantitative real-time reverse transcription PCR confirmed that the transcription of mviN was upregulated in the luxO mutant when compared with wild-type, and down regulated in a luxO-con complemented strain. Furthermore, Western blotting indicated that MviN was greatly induced during the late-exponential and stationary phases of growth, indicating that the expression of MviN was cell-density dependent and quorum sensing regulated in V. alginolyticus. Meanwhile, the mviN null mutant displayed a much slower growth rate than the wild type, signifying the essential role of MviN in V. alginolyticus. Western blotting also revealed that MviN was present as an extracellular protein in V. alginolyticus. When epithelioma papulosum cyprini (EPC) cells were treated with the ECPs of the mviN mutant, no cytotoxicity was observed, whereas EPC cells treated with the wild type exhibited pathological changes, which increased with the ECPs concentration and treatment time. Therefore, the results demonstrated that MviN is a LuxO-regulated ECPs component and involved in the pathogenicity of V. alginolyticus.

• 한국수산과학회지
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• 제48권2호
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• pp.178-186
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• 2015

Protease inhibitors (PI) of trypsin and papain as target proteases from the roe of bastard halibut Paralichthys olivaceus were fractionated out using ammonium sulfate precipitation (A), DEAE 650M anion exchange chromatography (D), and Sephacryl S-300 gel filtration (S). The recovery percentages of the fractions with the strongest inhibitory activity for each fractionation method were 13% for the A4 fraction, 21.2% for the D3 fraction, and 21.3% for the S2 fraction, with specific inhibitory activities of the fractions toward trypsin and casein of 168, 139, and 218 U/mg, respectively, while no inhibition of papain was observed. The $IC_{50}$ for the trypsin-specific substrate $N{\alpha}$-benzoyl-$\small{L}$-arginine-p-nitroanilide (BAPNA) was 0.65, 1.55, 2.26, and 2.85 mg/mL for the A4, S2, A3, and D3 fractions, respectively. These results suggest that chromatographic fractionation methods (D and S) based on the molecular mass and charge of the protein were more effective at fractionating PI than was ammonium sulfate precipitation based on protein solubility, and that the bastard halibut roe extract acts as a serine protease inhibitor. Therefore, the PI fraction from fish roe might be useful for inhibiting proteases in foodstuffs, and could constitute an alternative food-grade inhibitor for the surimi industry.

• 한국축산식품학회지
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• 제40권2호
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• pp.209-220
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• 2020

Milk fat globule membrane (MFGM) is a lipid carrier in mammals including humans that consists mainly of polar lipids, like phospholipids and glycolipids. In this study, a process to enrich polar lipids in commercial butter and whey powder, including polar lipids of MFGM, was developed. WPC (whey protein concentrate) 60 was selected as the most suitable raw material based on the yield, phospholipid, protein, and lactose content of the polar lipid fraction obtained by ethanol extraction of two WPC (WPC60 and WPC70) and two buttermilk (A and B). After fractionation under optimum conditions, the polar-lipid enriched fraction from WPC60 contained 38.56% phospholipids. The content of glycolipids, cerebroside, lactosylceramide, ganglioside GM3, ganglioside GD3, was 0.97%, 0.55%, 0.09%, and 0.14%, respectively. Rancimat results showed that the oxidation stability of fish oil increased with an increase in the polar-lipid fraction by more than 30 times. In addition, the secretion of IL-6 and TNF-α decreased in a concentration-dependent manner after treatment of RAW 264.7 cells with 0.1 to 100 ppm of the polar lipid fraction. In this study, polar lipid concentrates with antioxidant and anti-inflammatory activity, were prepared from milk processing by-products. The MFGM polar lipid concentrates made from by-products are not only additives for infants, but are also likely to be used as antioxidants in cooking oils and as active ingredients for functional foods.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1178-1187
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• 2000

Many immunostimulating substances have been developed to improve immunity of domestic animals, although their exact mode of action and effects are not clearly defined, and they are now widely used in feed industry. Bacterial lipopolysaccharides, called endotoxin, in particular may have a profound effect not only on the immune system but also on macrophages of the reticuloendothelial system. Glucans from a variety of yeast cell wall have been shown to stimulate both specific and non-specific immune responses and to increase growth performance in pigs. Recently, there has been great interest in the role of complex carbohydrates in disease prevention and treatment. Mannanoligosaccharide is a glucomannoprotein complex derived from the cell wall of yeast. Generally, it was also known that the deficiencies of some major vitamins (vitamin A, E and C) and minerals (chromium and selenium) lead to impaired immune system and, as a result, immune function is depressed and recovery delayed. On the other hand, many researchers suggested that one possible reason for the superior performance observed in pigs fed plasma protein may be because of the presence of biologically active plasma proteins (e.g., immunoglobulins) which are known to contribute to the health of the starter pig. And, immunoglobulins present in plasma protein have been implicated as contributing to the overall immunocompetence of the newborn pig. Other immunostimulants, lactoferrin and lysozyme, mainly found in milk and egg white, have been known as having bacteriocidal and bacteriolytic effect. When considering practical use of immunostimulants, the concept of using immunostimulants is new to many people and, in most cases, it is poorly understood how and why such compounds act, and how they should be used in practice. Therefore, in order to clarify the reason for discrepancies in results, special attention should be paid to the dose/response relationship of immunostimulants and the duration of the effect.

• Asian-Australasian Journal of Animal Sciences
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• 제19권6호
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• pp.872-876
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• 2006

The objective of this study was to evaluate Biocom (a protein source containing a high level of glutamine and alanyl-glutamine) as a replacement for glutamine (Gln) in nursery pig diets. Forty-two pigs (fourteen pigs per treatment) weaned at 28 d of age were used in a 28-d performance trial using three dietary treatments: control (no Gln), control supplemented with Gln or Biocom. The control diet was composed of corn, soybean meal, whey and fish meal. Individual body weight, pen feed disappearance and diarrhea were monitored. On d 0, 2, 7 and 14 postweaning, respectively, five pigs per treatment were selected and bled from the anterior vena cava to obtain five replicate samples of blood on each dietary treatment for determination of blood biochemical index. Dietary supplementation of Gln and Biocom did not influence performance, plasma Gln and total serum protein concentration (p>0.05). However, the addition of Gln and Biocom could prevent serum urea nitrogen and serum cortisol from increasing on d 2 postweaning (p<0.05). There were no significant differences (p>0.05) in any of the examined parameters between Gln- and Biocom-supplemented diets. In conclusion, dietary Gln did not influence the performance of early-weaned piglets owing to the complex diet containing whey, but could prevent the increase of serum urea and cortisol. Biocom could be used as a replacement for free pure Gln without any negative effect on early-weaned piglets.

• 한국수산과학회지
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• 제47권2호
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• pp.114-121
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• 2014

This study compared the food quality of domesticated(RT-DS) and freshwater (RT-F) rainbow trouts Oncorhynchus mykiss. The proximate composition of RT-DS was 73.8% moisture, 20.6% crude protein, 4.2% crude lipid, and 1.1% ash and was similar to RT-F. No differences were found in the red color, odor and taste intensities, calcium, and potassium between RT-DS and RT-F based on the Hunter a values, volatile basic nitrogen content, odor intensity and using an electronic nose, and taste intensity using an electronic tongue. The crude protein, total amino acid contents, and taurine, glutamic acid, glycine, alanine and anserine contents in free amino acids were higher in RT-DS than in RT-F. There was no difference in hardness between RT-DS and RT-F.

• 한국수산과학회지
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• 제47권2호
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• pp.103-113
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• 2014

This study compared the food quality of freshwater rainbow trout Oncorhynchus mykiss cultured (in Pyeongchang, Pyeongtaek, Jecheon and Geochang) with that of imported salmon Oncorhynchus keta. The proximate composition of the four types of rainbow trout was 74.4-75.7% moisture, 18.3-19.4% crude protein, 3.1-4.3% crude lipid, and 1.3-1.7% ash. There were slight differences in the proximate composition of the four types of rainbow trout. No significant (P>0.05) differences were found in the red color and odor and taste intensities of the four types of rainbow trout based on the Hunter a values, volatile basic nitrogen content, odor intensity using an electronic nose and taste intensity using an electronic tongue. The crude protein, total amino acid, and mineral contents of rainbow trout cultured in Pyeongtaek were superior or similar to those of the trout cultured in the other three places. The rainbow trout cultured in Geochang had the highest hardness, at 858.5 g.

• Fisheries and Aquatic Sciences
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• 제19권9호
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• pp.41.1-41.7
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• 2016

Background: The transgenic approach using estrogen-responsive regulator in fish has been given much attention as a potential means to detect and/or address estrogen-related aquatic pollutions. In order to address the development stage- and reproduction status-dependent expression patterns of the chgH-rfp transgene (red fluorescent protein transgene driven by choriogenin H promoter) in marine medaka Oryzias dancena, naturally occurring red fluorescent protein (RFP) signals under non-exposed conditions as well as the transgenically induced RFP signals under estrogen-exposed conditions were assayed. Results: Female transgenics begun to show naturally occurring RFP signals from the age of 7 weeks post hatching (WPH) without experimental estrogen exposure. Afterward, these RFP signals in female transgenics became robust with the progress of ovarian maturation. On the other hand, male transgenics did not show any naturally occurring RFP signal under non-exposed conditions irrespective of developmental stages and maturation statue. Upon exposures using estradiol-$17{\beta}$ (E2) and $17{\alpha}$-ethinylestradiol (EE2), RFP signals were significantly induced specifically in the livers of transgenic males. Conclusions: Male chgH-rfp transgenics were able to keep the "off" state of RFP expression during their entire life cycle unless exposed to exogenous estrogens. Owing to their tight regulation capability of estrogen-responsive transgene, transgenesis of chgH-rfp in male marine medaka could offer a useful model system for future ecotoxicogenomic studies regarding estrogenicity-related issues in aquatic and marine environments.

• Journal of Microbiology and Biotechnology
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• 제13권2호
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• pp.263-268
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• 2003

Recently, we identified a domain, termed MIRC3-4, for the protein-protein interaction between yeast chitin synthase 3 (CHS3) and chitin synthase 4 (CHS4). In this study, the functional roles of MIRC3-4 were examined at the G1 phase and cytokinesis of the cell cycle by Calcofluor staining and FISH. Some mutations in MIRC3-4 resulted in disappearance of the chitin ring in the early G1 phase, but did not affect chitin synthesis in the cell wall at cytokinesis. The chitin distribution in chs4 mutant cells indicated that CHS4 was involved in the synthesis of chitinring in the G1 phase and in the synthesis of cell wall chitin after cytokinesis, suggesting that Chs4p regulates chitin synthase 3 activity differently in G1 and cytokinesis. Absence of the chitin ring could be caused either by delocalization of Chs3p to the bud-neck or by improper interaction with Chs4p. When mutant cells were immunostained with a Chs3p-specific antibody to discriminate between these two alternatives, the mutated Ch3p was found to localize to the neck in all MIRC3-4 mutants. These results strongly irdicate that Chs4p regulates Chs3p as an activator but not a recruiter.

• Asian-Australasian Journal of Animal Sciences
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• 제28권6호
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• pp.855-861
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• 2015

Lactobacillus plantarum is used for fermentation of fish products, meat and milk. However, the utilization of these bacteria in egg processing has not been done. This study was designed to evaluate the potential of fermented egg albumen as a functional food that is rich in angiotensin I-converting enzyme inhibitors activity (ACE-inhibitor activity) and is antihypertensive. A completely randomized design was used in this study with six durations of fermentation (6, 12, 18, 24, 30, and 36 h) as treatments. Six hundred eggs obtained from the same chicken farm were used in the experiment as sources of egg albumen. Bacteria L. plantarum FNCC 0027 used in the fermentation was isolated from cow's milk. The parameters measured were the total bacteria, dissolved protein, pH, total acid and the activity of ACE-inhibitors. The results showed that there were significant effects of fermentation time on the parameters tested. Total bacteria increased significantly during fermentation for 6, 12, 18, and 24 h and then decreased with the increasing time of fermentation to 30 and 36 h. Soluble protein increased significantly during fermentation to 18 h and then subsequently decreased during of fermentation to 24, 30, and 36 h. The pH value decreased markedly during fermentation. The activities of ACE-inhibitor in fermented egg albumen increased during fermentation to 18 h and then decreased with the increasing of the duration of fermentation to 24, 30, and 36 h. The egg albumen which was fermented for 18 h resulted in a functional food that was rich in ACE-inhibitor activity.