• Korean Journal of Poultry Science
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• 제48권4호
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• pp.185-191
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• 2021

Chicken spermatozoa have the ability to survive in low-temperature environments; however, the effects of low temperature on sperm motility and acrosome damage have not been studied in detail. The present study investigated semen longevity following dilution of rooster semen with Beltsville Poultry Semen Extender (BPSE) and Lake extender in preservation vessels (1.5 mL e-tube and 0.5 mL straw). Spermatozoa motility in the closed-type vessel (0.5 mL straw) was higher than that in the 1.5 mL e-tube on day 3 of preservation (68.6±3.1% vs. 22.1±5.7%). The motility of rooster semen diluted with BPSE in 0.5 mL straw was also higher than that of the Lake extender on day 3 of preservation (57.7±5.6% vs. 37.7±5.4%). Furthermore, acrosome intactness was higher in 0.5 mL straw than in the 1.5 mL e-tube, and the rate of acrosome cap damage increased with preservation days. The present study demonstrates that a closed 0.5-mL straw vessel could be used for low-temperature semen preservation, with an increased motility rate and acrosome integrity in fresh rooster semen.

• Journal of Korean Society of Environmental Engineers
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• 제28권7호
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• pp.697-703
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• 2006

Endocrine disruptors were measured with GC/MS in effluents discharged from sewage treatment processes in pilot scale for the purpose of water reuse. From that analysis, we compared the removal rate of them by treatment processes. Nonylphenol was mainly detected in effluents and high concentration from 0.36 to 0.94 ${\mu}g/L$. $17{\beta}$-estradiol(E2) and $17{\alpha}$-ethynylestradiol(EE2) were detected as below the limit of detection in effluent. Endocrine disruptors were removed effectively in the range from 50 to 100% by treatment process. EC50 value($9.0{\times}10^{-3}$ M) of $17{\beta}$-estradiol(E2) by dose response curve of E-screen assay has higher than that of bisphenol A($2.736{\times}10^{-5}M$) and p-octylphenol($9.760{\times}10^{-6}$ M). These results showed that alkylphenols have lower relative estrogen potency than other estrogens such as $17{\beta}$-estradiol(E2). Calculated estrogenic activity(ng-EEQ/L) was 2 times higher than measured total estrogenic activity which estimated by E-screen assay. Moreover estrogenic activity of effluent by treatment process showed very low as below 1 ng-EEQ/L.

• Journal of Food Hygiene and Safety
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• 제13권4호
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• pp.365-369
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• 1998

The in vitro effects of trisodium phosphate and cetylpyridinium chloride on E. coli 0157:H7 and L. monocytogenes were investigated. The trisodium phosphate and cetylpyridinium chloride was bactericidal toward E. coli 0157:H7 and L. monocytogenes. The killing effects of the $1{\times}10^{-2}\;M$ trisodium phosphate on E. coli 0157:H7 and L. monocytogenes were 30~40%, 40~50%, respectively. The killing effects of the $5{\times}10^{-7}\;M$ cetylpyridinium chloride on E. coli 0157:H7 and L. monocytogenes were 90~95%, 95~99%, respectively. The killing effects of the trisodium phosphate was $10^5$ times that of the cetylpyridinium chloride. Factors effecting the bactericidal action of trisodium phosphate and cetylpyridinium chloride were investigated and the action depended on temperature and pH.

• Microbiology and Biotechnology Letters
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• 제26권1호
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• pp.61-67
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• 1998

Recombinant human epidermal growth factor (rhEGF) was produced by E. coli BL2l (DE3) harboring a plasmid pYHB101. The production of rhEGF was 44.5 mg/L when the E. coli BL2l (pYHB101) was cultured at 27$^{\circ}C$ for 48 hr in the modified MBL medium containing 10 $\mu\textrm{g}$/L glucose with 10 $\mu\textrm{m}$ IPTG/lactose induction at 2 hr after inoculation. It was shown that lactose is able to induce the rhEGF expression of E. coli BL2l (pYHB101) with the same efficiency as IPTG. In the batch culture system, when induced with 10 $\mu\textrm{m}$ lactose, E. coli BL2l (pYHB101) produced maximum 45 mg/L of the rhEGF at 28 hr culture in the modified MBL medium containing 10 g/L glucose. In the semi-fed batch culture system, the volumetric yield was 160 mg/L when the culture was added with 0.5% (w/v) lactose and 0.25% (w/v) yeast extract in the late logarithmic phase and 94.3% of rhEGF was secreted as soluble form. However, when the culture was added with them in the early logarithmic phase, the volumetric yield was 120 mg/L and 20.9% of rhEGF was found in cytoplasmic insoluble aggregates. It was found that the addition time of lactose was important for production of soluble rhEGF from E. coli BL21 (pYHB101).

• Korean Journal of Veterinary Service
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• 제46권4호
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• pp.325-334
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• 2023

Edema disease (ED) in pigs is enterotoxemia caused by Shiga toxin type 2e (Stx2e)-producing Escherichia coli (STEC) and frequently occurs in young piglets. Therefore, ED causes enormous economic losses in pig farms. In this study, a modified Stx2e (mStx2e) antigen was expressed and purified using commercial E. coli expression system. Monoclonal antibody was serviced by Ynto Ab Inc., using Phage Display Technique. Anti-Stx2e antibodies in piglets were measured by indirect ELISA using mStx2e antigens. Naive Stx2e in piglets were detected by Sandwich ELISA using Stx2e-monoclonal antibodies and commercial Stx2e-polyclonal antibodies. Among 3,480 piglets, anti-Stx2e antibodies were observed in 2,573 piglets. The 49.4% among 830 piglet serum samples possessed 0.625 ㎍/mL or more of Stx2e proteins. The 18.3% of 830 sera had 0.313 ㎍/mL of Stx2e proteins. The 32.3% of 830 samples held 0.156 ㎍/mL or less of Stx2e proteins. These results show that indirect ELISA using mStx2e antigen and Sandwich ELISA using Stx2e-monoclonal and polyclonal antibodies can be useful to detect ED in piglets.

• Journal of Food Hygiene and Safety
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• 제20권4호
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• pp.217-224
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• 2005

When L. monocytogenes ($10^{5}CFU/mL$) at exponential phase cells were heated for 5 min at $65^{\circ}C$ in the presence of the bacteriocin (30 BU/mL) produced by E. faecium MJ-14, the number of viable cells was markedly reduced at p < 0.05. The bactericidal effect of bacteriocin showed synergism with combination ot organic acids (citric acid or acetic acid) or chemical preservatives (sodium benzoate, sodium lactate, sodium nitrate or potassium nitrate). For example, the number of viable cells was reduced by 4.8 log units under combination of the bacteriocin (30 BU/mL) and sodium nitrate ($100{\mu}g/mL$), while it was reduced by 1.1 log unit only under single treatment of the bacteriocin after 12 k at $37^{\circ}C$. The addition of the bacteriocin (300 BU/mL) into skim milk inoculated with L. monocytogenes ($10^{5}$CFU/mL) reduced the cells by 1.5 log unit, in case of the cell suspension stored at $4^{\circ}C$ for 24 hr. Moreover, L. monocytogenes was reduced by 2 log unit when stored at $-20^{\circ}C$ for 7 days in gound pork added with 300 BU/mL of 린e bacteriocin.

• Journal of Food Hygiene and Safety
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• 제36권6호
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• pp.481-487
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• 2021

The purpose of this study was to provide safety management information by analyzing the survival and growth-related properties of foodborne pathogens from Romaine lettuce. After cultivating E. coli O157:H7 for 72 h on Romain lettuce via spray inoculation, the bacteria population increased by 2.0 log CFU/g from the initial population, confirming the possibility of survival and multiplication of the pathogen thereon. The study also revealed that there is no significant difference in the cultivation of E.coli O157:H7 after 72 h from inoculation on damaged and undamaged lettuce leaves. As a result of investigating distribution of E.coli O157:H7 on damaged lettuce leaves, it was found that the bacteria is unlikely to adhere on the smooth surface of undamaged leaves and, thus, results in a low population density, whereas the bacteria cluster on the rough surface of damaged leaves and easily enter through the damaged tissues. Furthermore, after 24 h of cultivation of the pathogenic microbe in the extract with concentrations of 10-100%, utilization of the lettuce extract by the pathogen was found to be 8.9 log CFU/mL E. coli O157:H7, 8.6 log CFU/mL L. monocytogenes, and 8.8 log CFU/mL P. carotovorum. The increase in the population of both the pathogenic microbe and foodborne pathogen reached over 4 log CFU/mL, implying the microbe can utilize the lettuce extract as a source of nutrition. Compared to the initial inoculation concentration in 0.1% lettuce extract, the final concentration has increased up to 2.7 log CFU/mL E. coli O157:H7, 1.3 log CFU/mL L. monocytogenes, and 2.9 log CFU/mL P. carotovorum. Accordingly, the study confirms that the minimal growth concentration of the pathogenic microbe is lower than 0.1% and that the pathogen possibly survive and multiply inside the lettuce leaves given the lettuce extract with concentration of 0.1% is consistently supplied through the damaged tissues.

• Journal of the Korean Society of Food Science and Nutrition
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• 제37권3호
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• pp.309-316
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• 2008

This study was carried out to examine the effects of vitamin E on chronic gastric ulcer induced by alcohol treatment in rats. Chronic gastric ulcer model was established by oral administration of 70% ethanol at one time and supply of 15% ethanol for additional 7 days. Male Sprague-Dawley rats, approximately 200 g, were fasted for 24 hours and orally gavaged with 1 mL of 70% ethanol for the induction of acute ulcer. A supply of 15% ethanol dissolved in distilled water for 7 days were followed to maintain chronic gastric ulcer. Acute ulcer group was sacrificed at 3 hours after oral administration of 1 mL of 70% ethanol. Chronic groups were divided into three groups according to vitamin E levels; low-vitamin E (LVE, 0 mg/mL oil/day), normalvitamin E (NVE, 1 mg/mL oil/day) and high-vitamin E (HVE, 10 mg/mL oil/day). These groups were fed vitamin E free diets which were made of vitamin E free vitamin mix followed AIN-93M pattern for 7 days. Histological findings of congestion, hemorrhage and necrosis in gastric tissue were shown severely in acute ulcer group and LVE group of chronic ulcer groups. The concentration of gastrin in serum was significantly higher in LVE group. The content of histamine in stomach was lower in acute ulcer group but there was no significant difference among the chronic groups regardless of vitamin E levels. Content of malondialdehyde (MDA) in gastric tissue was higher in HVE group and activities of antioxidant enzyme, glutathione peroxidase (GPx) and catalase, were lower in HVE group. Myeloperoxidase (MPO) activities as a marker of neutrophils infiltration was significantly higher in LVE group. These results suggested that vitamin E supplementation has positive effects on healing of alcohol-induced chronic gastric ulcer through alleviation of gastric tissue injuries and reduction of the MPO activity in gastric tissue and gastrin in serum.

• Journal of Life Science
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• 제12권6호
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• pp.688-693
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• 2002

Molecular chaperones prevent the misfolding of newly synthesized polypeptides in the cell. The coexpression of molecular chaperones could be expected to improve the production of soluble and active recombinant proteins. In this study, the effect of coexpression of E. coli GroEL/ES chaperone on the active production of Bacillus macerans cyclodextrin glucanotransferase (CGTase) in E. coli was investigated. Two plasmids, pTCGT1 and pGro7 in which the cgt and the groEL/ES genes are under the control of 77 promoter and araB promoter, respectively, were co-transformed into E. coli. With a series of cultures of recombinant E. coli cells, the optimal concentrations of IPTG and L-arabinose were found be 1 mM and 0.3 mg/$m\ell$, respectively. When IPTG and L-arabinose were added at 0.8~1.0 $OD_{600}$ and 0.4~0.5 $OD_{600}$, active CGTase production was increased significantly. This coexpression condition resulted in 1.5-fold increased level of soluble CGTase (0.7~0.73 unit/$m\ell$), compared to the level of CGTase in the single expression (0.36~0.56 unit/$m\ell$). An SDS-PACE analysis revealed that about 33.6% of CGTase in the total CGTase protein was found in the soluble fraction by coexpression of GroEL/ES chaperone.

• Journal of the Korean Society of Tobacco Science
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• 제27권1호
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• pp.19-30
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• 2005

This study was to evaluate the biological activity of flavor components extracted from E. ciliata and E. splendens in order to survey the possibility applicable to tobacco and food industry. Flavor components were extracted with dividing into three parts; essential oil, absolute, oleoresin. In the nonenzymatic lipid peroxidation system, the inhibition rate($\%$) of essential oil were $67.3\;\pm\;20.7\%,\;58.1\;\pm\;19.3\%$ at the concentration of 50 ${\mu}g/mL$ of E. ciliata and E. splendens, respectively. The inhibition rate($\%$) of the oleoresin in E. ciliata was higher than one in E. splendens. In the enzymatic lipid peroxidation system, the inhibition rate($\%$) of essential oil and oleoresin was$14.28\;\pm\;2.38\%,\;and\;65.93\;\pm\;0.01\%,\;and\;was\;22.58\;\pm\;2.84\%\;and\;40.73\;pm\;6.04\%$. The oleoresin of two species were showed above $90\%$ of the inhibition rate($90\%$) against autooxidative lipid peroxidation system. $EC_{50}$ values in neutral red uptake assays 24 h of exposure times were $23.3\;{\mu}g/mL,\;341.0\;{\mu}g/mL\;and\;17.2\;{\mu}g/mL$ in essential oil, absolute and oleoresin from E. ciliata respectively, and were $46.4\;{\mu}g/mL,\;681.7\;{\mu}g/mL\;17.6\;{\mu}g/mL$ in three extractions of E. splendens. Oleoresin of two species showed high rate in the cytotoxic effect by neutral red uptake assay. Absolute and oleoresin did not show antibiotic and mutagenic activity. On the contrary, essential oil with over 500 ug/plate showed antibiotic and mutagenic activity in Ames test. Essential oil and oleoresin have a prolongating effect the ciliostasis of rat trachea. This results indicate that flavor components extracted from E. ciliata and E. splendens can be considered to be toxicological safe and to be the possibility applicable the cigarette, food and drug industry as a flavor for expectoration.