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Aptness for the Preparation of Liquid Yogurt by Lactobacilli isolated from Korean Liquid Yogurts (국내 액상발효유에서 분리한 유산균의 제품제조 적성조사)

  • So, Myeong-Hwan
    • Korean Journal of Food Science and Technology
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    • v.17 no.3
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    • pp.197-202
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    • 1985
  • In order to evaluate the aptness for the preparation of liquid-yogurt, microbiological properties of 8 Lactobacilli isolated from 7 Korean liquid-yogurts were investigated. To accelerate acid-producing ability in skim milk, L. bulgaricus D, L. casei A and L. casei E need to supply with glucose, and L. Casei A and L. csaei E also need milk-protein hydrolyzate, but L. jugurti B, L. jugurti C, L. jugurti G, L. helveticus F and L. acidophilus B did not need those supplements. In cultivation in skim milk supplemented with glucose, L. jugurti B, L. jugurti C, L. jugurti G. L. helveticus F and L. bulgaricus D showed rapidity in acid development and weakness in cell viability, but L. acidophilus B, L. casei A and L. casei E showed slowness in acid development and highness in cell viability. Liquid-yogurts made by L. casei A or L. casei E had no sedimentation during storage but those made by L. jugurti B, L. jugurti C, L. jngurti G, L. helveticus F, L. bulgaricus D, or L. acidophilus B had much sedimentation. In sensory evaluation, Liquid-yogurts made by L. casei A or L. casei E had good response but those made by L. jugurti B, L. jugurti C, L. jugurti G, L. helveticus F, L. bulgaricus D or L. acidophilus B did not. Among 8 Lactobacilli examined, L. casei A and L. casei E were thought to have more suitable properties for the preparation of liquid-yogurt though they required a long period of cultivation.

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Interspecific Relationships of the Genus Leucophenga(Drosophiliae) by Electrophoretic Analysis of Protein (단백질 전기영동 분석에 의한 Leucophenga 속 (Drosophilidae) 초파리의 종간 유연관계)

  • 이택준;오준영
    • Animal Systematics, Evolution and Diversity
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    • v.7 no.1
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    • pp.65-72
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    • 1991
  • The interspecific relationships of the genus Leucophenga, L.concilia, L.maculata, L.orientalis , and L.quinquenmaculipennis were investigated by soluble proteins analysis. the electrophoretic banding patterns of the four species analyzed by SDS-PAGE were scanned by densitormeter. The soluble protein patters of L.maculata and L.concilia by SDS-PAGE appeared similarly and on the other hand, those of L.quinquemaculipennis had a different forms from three other species. The genetic distance among the four species of TDE analysis was calculated by formula of the Aquadro and Avis(1981) . The genetic distance between L.maculata and L.concilia was 0.393 , the lowest of all and between L.maculata and L.quinquemaculipennis was 0.496, the highest of all. The dendrogram was established using UPGMA method based on genetic distance obtained by TDE analysis. Clustered patterns as follows ; first, L.maculata and L.concilia were clustered, and L.orientalis and L. quinquemaculipennis followed the firstone in order. In consequence, it seems that the interspecific relationship of L.quinquemaculipennis was farther from the other three species, while that of L.maculata and L.concilia was closer than that of L.orientalis.

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Nitric Oxide/cGMP-Independent Vasorelaxation Enhanced by L-Arginine (L-Arginine의 산화질소생성과 무관한 혈관이완효과)

  • 문승호;이종은;유광재;오봉석;이동준
    • Journal of Chest Surgery
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    • v.31 no.2
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    • pp.102-107
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    • 1998
  • It has not been clear whether L-arginine plays solely a role contributing to vascular nitric oxide (NO) synthesis. To investigate the mechanisms by which L-arginine induces vasorelaxation, effects of L-arginine on the isometric tension, and tissue NOx and cyclic guanosine monophosphate(cGMP) contents were examined in the isolated rat thoracic aorta. L-Arginine induced a dose-dependent relaxation of aortic rings only with intact endothelium only. The vasorelaxation response to low concentrations of L-arginine was abolished by the pretreatment with NG-nitro-L-arginine methyl ester(L-NAME, 10-4 mol/L), whereas the relaxation caused by higher concentrations L-arginine(10-5-10-3 mol/L) was maintained and even more pronounced in the presence of L-NAME. L-Arginine did not affect the vascular tension precontracted with KCl. The vascular tissue contents of NOx/cGMP were not significantly affected by L-arginine, while they were decreased by L-NAME. L-Arginine could not completely recover the NOx/cGMP decreased by L-NAME. Methylene blue only partially antagonized the relaxation response to L-arginine. Indomethacin did not affect the L-arginine-induced vasorelaxation, whereas ouabain markedly attenuated the relaxation. It is suggested that L-arginine induces vasorelaxation not only through its contribution to NO synthesis, but also through enhancing another endothelium-dependent mechanism which is NO/cGMP-independent and cyclooxygenase- independent.

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The native distribution and flowering Characterestics of Lycoris genus (Lycoris 속(屬)의 자생지(自生地) 분포(分布) 및 개화특성(開花特性))

  • PARK, N.B.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.4 no.1
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    • pp.80-88
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    • 2002
  • This study was carried out to investigate the native distribution and flowering characteristics of Lycoris genus which is endemic species in Asia. This study was summarized as fellows: Native distribution of Lycoris genus was situated in latitude 37- 24 degrees with high humidity of coastline. Mininum temperature of native area was at -10℃ during winter season. The leaf of L. squamigera, L. koreana, L. sangunea, L. sprengeri, L. incanata and L. flavescens emergenced in spring. The leaf of L. radiata, L. rdiata var pumila, L. aurea, L. traubii, L. albiflora and L. houdyshelli emergenced in autum. Bulb of Lycoris genus show a sympodial branching system which is composed of 14-23 scales and 2.8-5.2 leaves per each bulb at flowering time. The flower shape of L. squamigera, L. Koreana, L, aurea, L. incanata, L. sprengeri, L. sanguinea and L. flavescens was trumpet. The flower of L. radiata. L. radiata var pumila, L. albiflora, L. houdchelli and L. traubii. was spider.

Studies on Antioxidative Effect and Lactic Acid Bacteria Growth of Persimmon Leaf Extracts (감잎 추출물의 유산균 생육 및 항산화 효과에 관한 연구)

  • Woo Jun-Young;Paek Nam-Soo;Kim Young-Man
    • The Korean Journal of Food And Nutrition
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    • v.18 no.1
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    • pp.28-38
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    • 2005
  • This study was investigated the growth effect of persimmon leaf extracts on various Lactic acid bacteria, the effect as freeze-dry cryoprotectan, by the changes of vitamin C content, electron donating ability, total cell count and SOD-like activity. The total cell count of L. acidophilus MG501, L. brevis MG19, L. bulgaricus MG515, L. lactis MG530 and L. casei MG311 in the absence of persimmon leaf extracts(10%) at 37℃ after 48hr were 3.2×10/sup 9/cfu/mL, 2.9×10/sup 9/cfu/mL, 1.1×10/sup 9/cfu/mL, 1.6×10/sup 9/cfu/mL and 3×10/sup 9/cfu/mL, respectively, and pH and total acidity of those were 3.82∼3.88, and 1.697∼1.842. On the other hand, the total cell count of L. acidophilus MG501, L. brevis MG19, L. bulgaricus MG515, L. lactis MG530 and L. casei MG311 in the presence of persimmon leaf extracts at 37℃ after 48hr were 4.4×10/sup 9/cfu/mL, 4.3×10/sup 9/cfu/mL, 2×10/sup 9/cfu/mL, 3.3×10/sup 9/cfu/mL, and 3.4×10/sup 9/cfu/mL, respectively, and pH and total acidity of those were 3.74∼3.82 and 1.528∼1.805. The total cell counter of lactic acid bacteria in the presence of persimmon leaf extracts(10%) at 37℃ after 48hr higher than those in the absence of persimmon leaf extracts. In freeze-dry chryoprotectan, the survival rate of L. acidphilus MG501 decreased about 30%. In case of L. brevis MG19 and L. bulgaricus MG515, the survival rate decreased about 10%. However, the survival rate of L. lactis MG530 increased about 10% and L. casei MG311 showed the almost same effect. The changes of vitamin C content were the highest in L. lactis MG530(190.26mg/mL) and the lowest in L. acidophilus MG501(56.05 mg/mL). The electron donating ability indicated to L. acidophilus MG501, L. brevis MG19, L. bulgaricus MG515, L. lactis MG530 and L. casei MG311 added by 10% persimmon leaf extracts, respectively. when 10% persimmon leaf extracts were added L. brevis MG19, the electron donating ability is the highest of all lactic acid bacteria. The SOD-like activity of L. acidophilus MG501, L. brevis MG19, L. bulgaricus MG515, L. lactis MG530 and L. casei MG311 showed lower than that of control.

Simulation Study of Dynamic Network Model for L-Threonine Biosynthesis in Escherichia coli (대장균의 동역학 네트워크 모델을 이용한 L-threonine 생합성에 관한 모사 연구)

  • Jung, Uisub;Lee, Jinwon
    • Korean Chemical Engineering Research
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    • v.44 no.1
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    • pp.97-105
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    • 2006
  • In order to investigate the effect of inhibitors on L-threonine biosynthesis in Escherichia coli, we have constructed a metabolic network model of amino acid biosynthesis from L-aspartate to L-threonine by using available informations from literatures and databases. In the model, the effects of inhibitors on the biosynthesis of L-threonine was included as an appropriate mathematical form. For simulation study, we used initial values as L-aspartate 5 mM, ATP 5 mM, NADPH 2 mM, and observed the concentration changes of intermediate metabolites over concentration changes of respective inhibitors. As a result, we found that concentrations of intermediate metabolites were not significantly changed over concentration changes of L-lysine, L-methionine, and L-glutamate. But, there were considerable changes of intermediates over concentration changes of L-serine, L-cysteine, and L-threonine, which can be considered as essential effectors on L-threonine synthesis. Contrary, the synthesis of L-threonine seems to be not related to the amounts of L-aspartate, and inversely proportional to the accumulated amount of D,L-aspartic ${\beta}$-semialdehyde.

Genetic Relationship Among Lycoris Species Using RAPD Analysis, the Native Distribution and Flowering Characteristics (Lycoris 속의 RAPD 분석과 자생지 분포 및 개화특성에 따른 유연관계)

  • Cha, Jae-Young;Jung, Yen-Ok;Shin, Sang-Min;Kang, Yun-Kyung;Park, Jong-Kun;Park, Nou-Bog
    • Journal of Life Science
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    • v.16 no.7 s.80
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    • pp.1119-1122
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    • 2006
  • Ten species of Lycoris was selected for establishment of phylogenetic relationships using random amplified polymorphic DNA (RAPD) analysis, the native distribution and flowering characterestics. On the basis of the dendrogram constructed with the similarity coefficients, 10 Lycoris species were divided into two clusters. L. sprengeri and L. incannta were showed very high similarity in the RAPD analysis, same flowering time and flower color as pink. The leaf of L. squamigera. L. sanguinea, L. koreana, L. sprengeri and L. incanata emergenced in spring. The L. squamigera and L. sanguinea were showed high similarity in same cluster. Also L. koreana, L. sprengeri and L. incanata were showed high similarity in same cluster. The flower of L. radiata, L. radiata var pumila, L. albiflora and L. traubii was spider. These species was showed very low similarity in another Lycoris species.

Selection of Mixed Lactic Acid Bacteria for Optimal Sponge Fermentation of Soda Cracker (소다 크레커의 최적 스폰지 발효를 위한 혼합젖산균의 선별)

  • Kim, Sang-Yong;Lee, Byung-Don;Kim, Jung-Min;Lim, Dong-Joon;Kim, Woo-Jung;Oh, Deok-Kun
    • Korean Journal of Food Science and Technology
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    • v.29 no.1
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    • pp.150-155
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    • 1997
  • The twenty strains of Lactobacillus genus were tested for the optimal sponge fermentation of soda cracker. The six strains such as L. brevis, L. delbrueckii, L. fermentum, L. leichmanii, L. plantarum and L. sanfrancisco were selected because these strains did not smell off-flavor and showed the high value of TTA (total titrable acidity) after the fermentation. The selected strains consisted of the five strains of L. brevis, L. delbrueckii, L. fermentum, L. leichmanii and L. plantarum that mainly inhabited soda clacker and L. sanfrancisco that existed in San Francisco bread. The lactic acid bacteria were inoculated to the medium containing 10% wheat flour and then pH, TTA, acetic acid and lactic acid were measured during the sponge fermentation. The four strains of L. brevis, L. delbrueckii, L. fermentum and L. plantarum were used for the mixed lactic acid bacteria of sponge fermentation because the TTAs of L. brevis, L. fermentum and L. plantarum were higher than those of other lactic acid bacteria and L. delbrueckii rapidly produced organic acids and a large amount of acetic acid. Among the combination of L. brevis, L. fermentum, L. delbrueckii and L. plantarum, the mixed lactic acid bacteria of L. brevis, L. fermentum and L. plantarum showed the highest TTA, the lowest pH and the largest amount of acetic acid. Therefore, the mixed lactic acid bacteria of L. brevis, L. fermentum and L. plantarum were used for optimal sponge fermentation of soda cracker.

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Raman Spectroscopy of L-Phenylalanine, L-Tyrosine, and their Peptides Adsorbed on Silver Surface

  • Lee, Hong-In;Kim, Myung-Soo;Suh, Se-Won
    • Bulletin of the Korean Chemical Society
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    • v.9 no.4
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    • pp.218-223
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    • 1988
  • The surface-enhanced Raman scattering of L-phenylalanyl-glycine (L-Phe-Gly), L-phenylalanyl-glycyl-glycine (L-Phe-Gly-Gly), glycyl-glycyl-L-phenylalanine (Gly-Gly-L-Phe), L-tyrosyl-glycine (L-Tyr-Gly), and L-tyrosyl-glycyl-glycine (L-Tyr-Gly-Gly) adsorbed on silver colloidal particles have been investigated. More detailed investigations on the surface-enhanced Raman scattering from L-phenylalanine (L-Phe), glycyl-L-phenylalanine (Gly-L-Phe), L-tyrosine (L-Tyr), and glycyl-L-tyrosine (Gly-L-Tyr) than in ref. 17 have also been made. It has been found that the above molecules adsorb on the surface via both the carboxylate ($COO^-$) and amino ($NH_2$) groups.

GPS L5 Signal Tracking Scheme Using GPS L1 Signal Tracking Results (GPS L1 신호추적 결과를 이용한 GPS L5 신호추적 기법)

  • Joo, Inone;Lee, Sanguk
    • Journal of Satellite, Information and Communications
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    • v.7 no.3
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    • pp.99-104
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    • 2012
  • The United States will proceed with the effort to modernize the GPS system, and one of its main content is to provide L5 signal. L5 will be transmitted in a radio band reserved exclusively for aviation safety services. And, L5, in combination with L1, will improve the position accuracy via ionospheric correction and robustness via signal redundancy. However, The acquisition processing time of L5 takes longer than that of L1 as the code length of L5 is 10 times longer than that of L1. To reduce this acquisition processing time, a higher number of correlators in the aquisition module should be used. However, there is a problem that this causes increase in the complexity of the correlator configuration and the computation power. So, in this paper, we propose L5 signal tracking scheme using tracking results in the GPS L1/L5 receiver. The proposed scheme could reduce the hardware complexity as the GPS L5 signal acquisition module is not needed, and provide fast and stable tracking of L5 signal by aiding L1 tracking results such as PRN, the code phase synchronization, and the Doppler frequency. The feasibility of the proposed scheme is demonstrated through simulation results.