• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.551-561
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• 1998

Plasma membrane from the fungal cells (Aspergillus phoenicis, Rhizopus acidus, Candida albicans) treated with sodium benzoate (S.B), potassium sorbate (P.S) and calcium propionate (C.P) during the cultivation were separated. The contents and patterns of plasma membrane proteins compared with those of the control. The growth of A. phoenicis was decreased by the average 64.0% in the S.B treatment. That of R. acidus was inhibited by the average 69.0% in the P.S treatment. Also, That of C. albicans was showed the deminution of the average 59.5% in the S.B treatment. The contents of protein involved in the plasma membrane of the each fungal cells were inhibited the average 41.0%, 41.7% and 59.5% in the S.B treatment, respectively. In case of A. phoenicis, the changes in the protein pattern involved in the plasma membraneshowed the aspect similar to the control on the 1st day and 2nd day of cultivation in the treatment group, but $116\;KD{\sim}97\;KD$ band almost disappeared in the 5th day of cultivation, and $45\;KD{\sim}29\;KD$ band was uncleared through the cultivation. In S.B treatment group R. acidus was showed the loss of $116\;KD{\sim}97\;KD$ band from the middle stage of cultivation and P.S, and C.P treatment group were started the loss at the early stage and completely lost at the 36 hours of cultivation. In C. albicans, $116\;KD{\sim}97\;KD$ band were started the loss at the early stage to compare with the control and $66\;KD{\sim}45\;KD$ band were dimmed at the 96 hours of cultivation. Especially, the C.P treatment group were perfectly lost at the 96 hours of cultivation.

• Journal of Korean Society of Transportation
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• v.31 no.2
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• pp.45-59
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• 2013

This study deals with the comparative analysis between two freight demand estimation methods : Unimodal O/D based method and P/C based method. The data of access/egress truck trips has been omitted from the Korean freight unimodal O/D of KTDB. This is because KTDB's unimodal O/D has not marked the series of unlinked trips down as the whole freight intermodal transport and surveyed only the main-haul trips of them. For these reasons, freight intermodal transport mechanism has not been analysed perfectly with Korean unimodal O/D data. This study tries to estimate P/C table of Korean Import/Export container freight and develop the MCC(Multimodal Channel Choice) model. Then, comparing unimodal O/D based method and P/C based method in terms of the switch commodities between production point(the initial point of freight transport) and consumption point(the terminal point of freight transport), unimodal commodities, and commodities on links is conducted. The results show that the P/C based method is able to simulate the freight intermodal transport.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.259-264
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• 2001

It has been well known that the expression of S. typhimurium cadBA operon requires at least two extracellular signals: low pH and high concentration of lysine. To better understand the nature of pH-dependent and lysine dependent signal transduction, mutants were isolated in JF2238(cadA-lacZ) by Tn10 insertion, spontaneous mutagenesis, and EMS treatment. Two mutants were isolated from JF2238, expressed as a cadA-lacZ operon fusion in various growth conditions, and analyzed to have mutations in cadC, a gene encoding a function necessary for transcriptional activation of cadBA. One isolate (cadC6) conferred pH-independent and lysine-independent cadBA expression and the other(cadC4) showed pH-independent and lysine-dependent cadBA expression. cadR::Tn10 and cadR4 mutants were expressed in the absence of exogenously added lysine. They were also resistant to thiosine and complemented by lysP clone from E. coli. Thus, in the absence of exogenous lysine, cadR is a negative regulator of cadBA expression. Cadaverine, the product of lysine decarboxylation, was shown to inhibit expression of cadA-lacZ fusion in cad $C^+$ cell.

• Korean Journal of Poultry Science
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• v.6 no.1
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• pp.24-30
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• 1979

1. The effects of heat stress (38$^{\circ}C$), cold stress (4$^{\circ}C$) and extreme cold stress (-20$^{\circ}C$) before slaughter on the tenderness and postmortem glycolysis if the excised chicken breast muscle were studied Heat stress significantly (p 0.05) increased the toughness of breast muscle. Though statistically not significant, cold stress also adversely affected the tenderness. The heat-stressed birds showed higher zero hr glycogen higher zero hr pH and significantly (p 0.05) love. ultimate pH then the controls. The cold-stressed birds showed intermediate values in these parameters. Highly significant correlations. were observed between shear value and each of these three parameters. Glycolysis rate ana final moisture content were minor factors which affected the muscle tenderness to a limited extent. The slightly elevated lactate-dehydrogenase and creatine phosphokinase activities in serum and breast muscle of stressed birds failed to account for any variations in tenderness. 2. Chicken breast and thigh muscles were subjected to different environmental temperatures to determine if the phenomenon of cold shortening exists in chicken muscle. For both breast and thigh muscles, minimum shortening was observed in the 4-10$^{\circ}C$t range. Muscles held at 0$^{\circ}C$ showed a slightly higher extent of shortening than at 4$^{\circ}C$; where as muscles held at above 20$^{\circ}C$ showed a severe shortening effect. It was concluded that no apparent cold shortening was detected in chicken muscle except at 0$^{\circ}C$ and even at 0$^{\circ}C$ and even at 0$^{\circ}C$ the extent of shortening was of a small magnitude compared to bovine muscles. Since high temperature induces a much greater shortening, muscle temperature must be lowered to below 20$^{\circ}C$ as early as possible to prevent excessive muse]e shortening.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.104-110
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• 2004

To determine evolution and genotype of new chromosomal AmpC $\beta$-lactamases among clinical isolates of Enterobacter species, we performed antibiotic susceptibility testing, pI determination, sequencing, and phy-logenetic analysis using developed expression/secretion vector. Six isolates have shown to produce AmpC $\beta$-lactamases. Six genes of AmpC $\beta$-lactamases that are responsible for the resistance to cephamycins (cefoxitin and cefotetan), amoxicillin, cephalothin, and amoxicillin-clavulanic acid were cloned and characterized in pMSG12119. Insert fragment containing the ampC genes was sequenced and found to have an open reading frame coding for 381-amino-acid $\beta$-lactamase. The nucleotide sequence of four ampC genes ($bla_EcloK992004.l$, $bla_EcloK995120.1$, $bla_EcloK99230$, and $bla_EareK9911729$) shared considerable homology with that of chromosomal ampC gene ($bla_EcloMHN1$) of E. cloacae MHN1 (more than 99.6% identity). The sequences of two ampC genes ($bla_EcloK9973$ and $bla_EcloK9914325$) showed close similarity to the chromosomal ampC gene ($bla_EcloQ908R$) of E. clo-acae 908R (99.7% identity). The results from phylogenetic analysis suggested that six ampC genes could be originated from $bla_EcloMHN1$ / or $bla_EcloQ908R$ / MIC patterns and exact pI values of six transformants indicated that the developed expression/secretion vector (pMSG1219) was suitable for the characterization of foreign genes in E. coli strain.

• Journal of the Korean Applied Science and Technology
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• v.9 no.2
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• pp.149-156
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• 1992

Levels of total lipids in the seeds of three species of the Pinaceae family were determined and their fatty acid compositions were also analyzed by a gas-chromatograph equipped with a capillary column coated with Carbowax 20M. The results are summarized as follows: Lipid contents of the seeds amounted to 56.9% in P. koraiensis, 29.9% in P. thunbergii, and 21.2% in P. rigida. In all lipids 19${\sim}$20 fatty acid were detected and, surprisingly, fatty acids having ${\Delta}^5$-non-methylene interrupted conjugate double bond such as ${\Delta}^{5, 9}-C_{18:2},{\Delta}^{5, 9, 12}-C_{18:3}\;and\;{\Delta}^{5, 11, 14}-C_{20:3}$ occurred in appreciable amounts. In the lipids of P. koraiensis, the main component was $C_{18:2}{\omega}_6(45.0%)$, followed by $C_18:1{\omega} _9(26.9%)$ and ${\Delta}^{5, 9, 12}-C_{18:3}(14.6%)$, and then ${\Delta}^{5, 9}-C_{18:2}(2.2%)$ and ${\Delta}^{5, 11, 14}-C_{20:3}$ were also present. Levels of saturated fatty acid such as $C_{16:0}\;and\;C_{18:0}$ were as low as 7.5%. The seed oil of P. thunbergii predominantly comprised $C_{18:2}{\omega}_6(45.2%)$, and was then occupied by equal amounts ${\Delta}^{5, 9, 12}-C_{18:3}(18.1%)$ and $C_{18:1}{\omega}_9(18.1%)$. Its ${\Delta}^5, 11, 14}-C_{20:3}(5.8%)$ level was the highest in the samples tested. ${\Delta}^{5, 9}-C_{18:2}(2.8%)$ was also detected with other minor components. In the oils from the seeds of P. rigida, $C_{18:2}{\omega}_6$ was present as a main component, accompanied by $C_{18:1}{\omega}_9(21.6%)$ and ${\Delta}^{5, 9, 12}-C_{18:3}(20.3%)$. The latter showed higher level than in any other samples. A minor component corresponding to ${\Delta}^{5, 9, 12, 15}-C_{18:4}$(not confirmed by GC-Mass) occurred in P. thunbergii and P. rigida.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.69-79
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• 2004

A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins). vitamin C-. or vitamin E-supplemented. and combined supplementation of the two vitamins. After a ten-day-adaptation period at 25 $^{\circ}C$. the ambient temperature was kept at 32 $^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (P<0.05). However. egg weight. SG. shell thickness. SWUSA. puncture force and shell breaking strength of the birds fed the diet with the combined vitamins C and E were significantly improved than those fed the basal diet during the heat stress period (P<0.05). The hens fed the vitamin C supplemented diet showed a tibia breaking strength of 37.16 kg statistically higher than those of the basal and the vitamin E supplemented groups (P<0.05). The hens fed the basal diet showed higher serum corticosterone levels. a mean of 5.97 ng/ml. than those of the rest of treatments (P<0.05). The heat stress elevated heterophils but decreased lymphocytes in serum. and it changed H/L ratios of all the treatments. The increases in H/L ratios were alleviated in the bird by feeding vitamin C and/or vitamin E supplemented diets. but they did not differ significantly (P<0.05). In conclusion. vitamins C (200 mg/kg) and/or E (250 mg/kg) supplementation to diets could prevent drops in egg shell quality and tibia bone strength by alleviating stressful effects from high temperature in broiler breeder hens.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.103-107
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• 2005

Immunomodulatory activities of crude ${\beta}$-glucans extracted from oat bran under different conditions, fractions A ($55^{\circ}C,\;5%,\;pH\;6$), B ($45^{\circ}C,\;15%,\;pH\;6$), C ($50^{\circ}C,\;20%,\;pH\;7$), D ($50^{\circ}C,\;0%,\;pH\;7$), and E ($50^{\circ}C,\;10%,\;pH\;9$) were investigated. All crude ${\beta}$-glucan fractions stimulated macrophages, producing nitric oxide dose-dependently, and, efficiently promoted nitric oxide production in presence of IFN-${\gamma}$. Except for fraction C, in vivo test indicated fractions B, D, and E (100 mg/kg) substantially enhanced carbon-phagocytic indices of blood macrophages by oral administration of crude ${\beta}$glucan for 7 days prior to carbon injection. These immunomodulatory effects could be determined with extraction conditions of crude ${\beta}$-glucan.

• 한국해양학회지
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• v.29 no.2
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• pp.107-118
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• 1994

An investigation of the annual change and C:N:P ratio in particulate organic matter (POM) in Chinhae Bay, a semi-enclosed bay of the southern coast of Korean Peninsula, was carried out for a period of 12 months between January and December, 1993. The concentrations of POM have a broad range: 198∼4,416 ugC/l, 24∼792 ugN/l and 4.5∼69.0 ugP/l, Marked seasonal changes of POM, particularly particulate organic carbon (POC) and nitrogen (PON), were observed in the surface water. Generally, the concentration of POM peaks in summer. The C:N:P composition ratio of particulate organic matter, which is high in summer, also shows a seasonal change. The C:N assimilation ratio is constant at 6.53, which is consistent with the Redfield ratio. The significant linear relationship between POM and chlorophyll-a in the surface water during the survey period (except for January and February) and the C:N ratio suggest that the concentration of POM is controlled by phytoplankton biomass. POM peaks in summer, a period characterized by high freshwater input and the strong stratification, as a result of the intense proliferation of phytoplankton by a large amount of nutrient loading from the tributaries. On the other hand, the high C:P and N:P ratios in summer indicate that P is limited for phytoplankton growth owing to N-enrichment from a high input of freshwater with a high dissolved inorganic N:P ratio.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.556-562
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• 1997

Depletion of nitrite by lactic acid bacteria isolated from Kimchi and the effects of pH and temperature on depletion of nitrite in Lactobacillus MRS broth were investigated. Depletion of nitrite by Lactobacillus plantarum and Lactobacillus sake was low in initial stage of growth but increased during growth at 15 and 2$0^{\circ}C$. L. plantarum and L. sake depleted than 90 and 75% of nitrite(250$\mu\textrm{g}$/$m\ell$) in 1 day of growth at 25 and 3$0^{\circ}C$, respectively, but depleted almost all of nitrite in 2 days. While the effect of Leuconostoc mesenteroides (150$\mu\textrm{g}$/$m\ell$) was lower compared to Lactobacillus(250$\mu\textrm{g}$/$m\ell$). In addition, even high concentrations(600 and 900 $\mu\textrm{g}$/$m\ell$) of nitrite was depleted at 2 days of growth by L. plantarum. pH of growing broth decreased as the increase of growth time and temperature, and depletion of nitrite in- creased as the decrease of pH of growing culture. However, pH of broth related with the decrease of depletion of nitrite at 25 and 3$0^{\circ}C$, but not at 15 and 2$0^{\circ}C$. Therefore, depletion of nitrite was greatly affected by growth temperature rather than by pH.