• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.6
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• pp.714-719
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• 2018

We investigated the effects of water temperature on physiological parameters in the chicken grunt Parapristipoma trilineatum. At high temperature, the aspartate aminotransferase (AST) and the alanine aminotransferase (ALT) levels were increased, suggesting that high temperature induced hepatic damage. In addition, total protein (TP) was high at high water temperatures, which were considered stressful in the breeding environment. At high water temperatures, triglycerides (TG) were low due to increased metabolic activity, which decreased the blood TG levels as TG were used as an energy source. There was no significant difference in the plasma osmolality or the blood ion concentrations with water temperature. In generally, lysozyme, a factor in innate immunity, increased with water temperature. However, lysozyme activity tended to decrease with increasing water temperature, but the difference was not significant. These results suggested that the decrease of biophylaxis at high temperature was affect the growth or survival of the population.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.348-352
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• 1999

We have intended to accelerate the secretion of human lysozyme(HLY) with permeabilizing agents from the cultivated cells of the recombinant Saccharomyces cerevisiae. The five agents CaCl2, Tween 80, ethanol, Triton X 100, and cetyltrimethylammonium bromide(CTAB) were used as permeabilizing agents. Treatments of the yeast cell with CaCl2, Tween 80, and ethanol were effective to increase the secretion from the yeast cells. Especially, treatment of 10% ethanol increased the extracellular HLY activity by 38.6% at 30oC for 48 h in culture broth. But Triton X 100 and CTAB unexpectedly didn't play a role in increase of HLY secretion. Recovery of a foreign protein by permeabilizing agents is easier than by osmotic shock, and is less expensive than enzymatic digestion.

• Journal of fish pathology
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• v.20 no.2
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• pp.189-200
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• 2007

To investigate the innate immune response involved in early stage of anti-viral defence, carps were injected with UV-inactivated spring viraemia of carp virus (SVCV), poly inosinic:cytidylic acid (Poly I:C) and concanavalin A (Con A), respectively and examined lysozyme activity, serum complement activity and chemiluminescent (CL) response of leucocytes isolated from head kidney at 3 days post-injection. There was no significant difference in plasma lysozyme activities among all experimental groups. However, lysozyme activities of head kidney in the groups injected with antiviral activity inducers were significantly higher than those of the control injected with physiological saline. Bactericidal activities of serum of the groups injected with antiviral activity inducers were not significantly different from control group. However, the CL responses were significantly higher at lower dose of Poly I:C and Con A, whilst dose-dependent increase was shown in UV-inactivated SVCV-injected group. In the challenge test with 1×104 TCID50/fish of SVCV at 4 days post-injection, UV-inactivated SVCV- and Poly I:C-injected groups showed higher relative percent survival (RPS) than Con A-injected group. Furthermore, strong protection was observed in the group injected higher dose of Poly I:C although showed lower activities in lysozyme and CL response. These results suggested that Poly I:C might stimulate other factors belonging to non-specific immune system have induced protective immunity against the SVCV challenged.

• Food Science of Animal Resources
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• v.38 no.3
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• pp.636-652
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• 2018

The study aims to determine the optimum sterilization rate and water activity of Chinese traditional smoke-cured bacon product (Larou) in the preservation with natural coating solution. With the response surface methodology (RSM), we analyzed 3 factors of processing conditions (the concentration of lysozyme, concentration of sodium alginate, and concentration of chitosan) and 2 response factors (sterilization rate and water activity). Sterilization rate and water activity of Larou were largely affected by the concentration of lysozyme, concentration of sodium alginate, and concentration of chitosan. The final optimum concentrations of lysozyme, sodium alginate, and chitosan were 0.09, 1.40, and 1.60% and realized the high sterilization rate. Water activity of sliced Larou was significantly correlated with the sterilization rate. Low-field nuclear magnetic resonance analysis verified the optimum processing conditions. The coating resulted in 99.69% rate of reducing bacteria after 30-day storage. The data of the total number of colony, peroxidation value, moisture content, pH, and sensory evaluation provided the theoretical basis for extending the shelf life of Chinese traditional smoke-cured bacon product (Larou) with natural coating solution.

• Animal cells and systems
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• v.15 no.1
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• pp.29-36
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• 2011

Insect lysozymes are basic, cationic proteins synthesized in fat body and hemocytes in response to bacterial infections and depolymerize the bacterial cell wall. The c-type lysozyme of the insect Spodoptera litura (SLLyz) is a single polypeptide chain of 121 residues with four disulfide bridges and 17 rare codons and is approximately 15 kDa. The full-length SLLyz cDNA is 1039 bp long with a poly(A) tail, and contains an open reading frame of 426 bp long (including the termination codon), flanked by a 54 bp long 5' UTR and a 559 bp long 3' UTR. As a host for the production of high-level recombinant proteins, E. coli is used most commonly because of its low cost and short generation time. However, the soluble expression of heterologous proteins in E. coli is not trivial, especially for disulfide-bonded proteins. In order to prevent inclusion body formation, GST was selected as a fusion partner to enhance the solubility of recombinant protein, and fused to the amplified products encoding mature SLLyz. The expression vector pGEX-4T-1/rSLLyz was then transformed into E. coli BL21(DE3)pLysS for soluble expression of rSLLyz, and the soluble fusion protein was purified successfully. Inhibition zone assay demonstrated that rSLLyz showed antibacterial activity against B. megaterium. These results demonstrate that the GST fusion expression system in E. coli described in this study is efficient and inexpensive in producing a disulfide-bonded rSLLyz in soluble, active form, and suggest that the insect lysozyme is an interesting system for future structural and functional studies.

• Korean Journal of Veterinary Research
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• v.34 no.4
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• pp.857-866
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• 1994

The present study was undertaken to examine the effects of obioactin, lonomycin A, and MDP on toxoplasmacidal activities in glycogen-induced mouse peritoneal macrophages. The killing effect of obioactin on Toxoplasma multiplication was increased significantly in proportion to its concentrations. $O_2{^-}$ generation in obioactin-treated macrophages was also increased from twofold to threefold when compared with that of untreated control. Similarly, $H_2O_2$ continued to rise in parallel with increase of the concentration of obioactin. Lonomycin A-treated macrophages also exhibited a good effect of dose-response on toxoplasmacidal activities. However, $O_2{^-}$ and $H_2O_2$ were not generated significantly in lonomycin A-treated macrophages. Macrophages treated with muramyl dipeptide (MDP) were not found to inhibit the prolifi:ration of Toxoplasma but showed the enhancement of $O_2{^-}$ and $H_2O_2$, generation. The released lysozyme levels from macrophages into cultured media were decreased tn dose-dependent fashion by in vitro treatment of obioactin, lonomycin A, and MDP. The intracellular lysozyme levels appeared to be a constant value regardless of increasing the concentrations of obioactin, lonomycin A, and MDP. Therefore, these results suggest that Toxoplasma multiplication within macrophages treated with obioactin was inhibited by the generation of $O_2{^-}$ and $H_2O_2$ and that lysozyme per se within or released from macrophages had no effect on toxoplasmacidal activity.

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.595-602
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• 2006

The purpose of this study is to demonstrate antimicrobial activities of the lactoferrin and its peptic hydrolysates obtained from the colostrums of Hanwoo(Korean native cattle) and Holstein cattle. In the measurement of antimicrobial activity to E. coli O111 and other microorganisms, bovine lactoferrin showed a higher antimicrobial activity than that of Hanwoo cow's lactoferrin . The minimal inhibitory concentration (MIC) of lactoferrin against E. coli O111 was exhibited 1.5mg/ml(Holstein) and 2.75mg/ml (Hanwoo). The same result was also observed between bovine lactoferrin hydrolysate (0.12mg/ml) and Hanwoo cow's lactoferrin hydrolysate (0.25mg/ml). In addition of lysozyme, antimicrobial activity of lactoferrin was increased.

• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.526-529
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• 2012

The present study was aimed to investigate the effect of a probiotic, Enterococcus faecium, on the immune responses against infection with the marine fish pathogen Lactococcus garvieae in olive flounder (Paralichthys olivaceus). The immune responses were assessed by lysozyme activity, complement activity, protease activity, and expression of proinflammatory cytokines by RT-PCR. The lysozyme and complement activities were increased between 9 to 15 and 9 to 13 days, respectively, and antiprotease activity was slightly elevated after 5 days of probiotic treatment. The TNF-${\alpha}$ and IL-$1{\beta}$ expressions were observed from kidney and spleen. The results of this study reveal that E. faecium induces immune-responsible materials and protects olive flounder from lactococcosis.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.93-99
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• 2018

Lysozyme is present in tears and has the ability to inhibit bacterial growth. In addition, it acts as a physiological scavenger for harmful substances. In the present study, sixteen tear samples from people of different ages were evaluated for their antibacterial spectrum against selected bacterial strains (Escherichia coli, Shigella sonnei, Staphylococcus aureus, Salmonella enterica Typhi). A radial diffusion assay was used to evaluate the antibacterial potential of tear samples. To correlate the antibacterial activities of these tear samples, the concentration of lysozyme in the tear samples was also determined. Ampicillin was used as a standard drug. The zone of inhibition (mm) was used to measure the antibacterial property of the tears. All samples showed good antibacterial activities. The tear samples of children showed antibacterial activities in the range of 4.40~5.00 mm inhibition zones against the selected bacterial strains. The tear samples from the young and adults showed good antibacterial potential with a zone of inhibition in the range of 3.20~4.00 and 4.00~5.50 mm, respectively. The tear samples from the old age group showed inhibition zones from 1.50~5 mm. The adult tear samples showed the maximum inhibition against the selected bacterial strains among all groups. The lysozyme concentration was 1.7 mg/mL, 1.95 mg/mL, 2.13 mg/mL, and 1.76 mg/mL for children, young, adults, and elderly, respectively. In conclusion, the tears from adults have the high inhibition potential. In addition, this data also showed that the lysozyme contents in the tear sample increased with age until 40~42 years.

• Korean Journal of Agricultural Science
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• v.21 no.2
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• pp.122-132
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• 1994

Bacteriostatic activity of secretory immumoglobulin A (SIgA) in human and bovine colostrums on enterotoxigenic type Salmonella was tested in the tissue culture medium. SIgA was used in $0.1{\sim}5.0mg/m{\ell}$ concentration with or without the addition of egg lysozyme tested for theirs bacteriostatic activites. 1. Bovine SIgA rich fraction with a large amount of $IgG_1$-dimer could be prepared from bovine colostrum of Holstein cows by anion exchange chromatography using DEAE-Sephadex A-50 and gel filtration on Sephadex G-200 and Sepharose 6B. 2. Human SIgA appeared to be the most bacteriostatic effect for all varieties of Salmonella in a range of $0.5{\sim}1.0mg/m{\ell}$ Bovine SIgA showed a marked bacteriostatic effect increased by increasing the concentration. Bovine IgG had not show bacteriostatic effect against both enterotoxigenic type Salmonella. Egg lysozyme as well as bovine SIgA also showed a marked bacteriostatic effect increased by increasing the concentration. 3. When the growth inhibition of human SIgA was tested by adding egg lysozyme with time interval, egg lysozyme showed bacteriostatic effect as compared with control. But human SIgA and adding with lysozyme showed slight the bacteriostatic effect. 4. When the growth inhibition of bovine SIgA was tested by adding egg lysozyme with time interval, all treatment against S. enteritidis showed bacteriostatic effect as compared with control In the case of S. typhinwrium, egg lysozyme showed a marked bacteriostatic effect as compared with control.