• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1067-1072
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• 2002

Peroxidase was used as a standard enzyme to determine optimum blanching conditions of Flammulina velutipes and Lyophyllum ulmarium. Crude peroxidase extracted from raw mushrooms had maximum activity at $10{\sim}15^{\circ}C$ and pH 5.5 (50 mM, potassium phosphate buffer) using substrates of $H_2O_2$ and p-Phenylendiamine. Thermal inactivation of the crude peroxidase followed the first-order kinetics. The activation energy and z value of the crude peroxidase for F. velutipes were 59.58 kcal/mol and $9.0^{\circ}C$, whereas were 43.05 kcal/mol and $12.4^{\circ}C$ for L. ulmarium, respectively. On the basis of thermal kinetics parameters obtained, the optimum blanching conditions for F. velutipes and L. ulmarium were 1 min at $70^{\circ}C$ and 5 min at $80^{\circ}C$, respectively. Activation energies and z values of peroxidases extracted from heat-treated mushrooms were 7.97 and 6.55 kcal/mol, and $59.8^{\circ}C\;and\;74.1^{\circ}C$ for F. velutipes and L. ulmarium, respectively.

• Bulletin of the Korean Mathematical Society
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• v.58 no.1
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• pp.21-30
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• 2021

In this paper, we prove some rigidity results about embedded minimal hypersurface M ⊂ ℝn+1 with compact ∂M that has one end which is regular at infinity. We first show that if M ⊂ ℝn+1 meets a hyperplane in a constant angle ≥ ��/2, then M is part of an n-dimensional catenoid. We show that if M meets a sphere in a constant angle and ∂M lies in a hemisphere determined by the hyperplane through the center of the sphere and perpendicular to the limit normal vector nM of the end, then M is part of either a hyperplane or an n-dimensional catenoid. We also show that if M is tangent to a C2 convex hypersurface S, which is symmetric about a hyperplane P and nM is parallel to P, then M is also symmetric about P. In special, if S is rotationally symmetric about the xn+1-axis and nM = en+1, then M is also rotationally symmetric about the xn+1-axis.

• Korean Journal of Animal Reproduction
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• v.8 no.2
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• pp.110-115
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• 1984

These experiments were carried out to obtain the information about the optimal pH osmolality affecting in vitro fertilization of the mouse eggs, to elucidate the 2-cell block to development in vitro and to find out the method of controlling the subsequent embryo development in vitro. pH and osomlality was adjusted by adding NaCl or NaHCO3 to the basic salt solution. In vitro fertilization were carried out by inroducting the cumulus masses to the suspension of epididymal spermatozoa at each pH, osmolality, and 10${\mu}$M-EDTA medium. The results obtained in these experiments were summarized as follows: 1. The fertilization rates in vitro at each medium of 235, 252, 269, 286, 306, 323, 345, 368, 393 mosmol were 15.6, 38.2, 65.7, 75.6, 80.9, 74.3, 58.1, 35.1, 24.3, 11.1%, respectively. 2. The fertilization rates in vitro at each medium of pH 6.1, 6.4, 6.7, 7.0, 7.3, 7.6, 7.9, 8.1 were 11.8, 17.9, 32.4, 61.9, 79.5, 76.7, 53.5, 13.6%, respectively. 3. In case of ICR female x ICR male embryos, the development rate of 2-cell embryos to 4-8 cell embryos was 16.2% at normal medium, but the rate was increased to 49.3% in medium containging 10 ${\mu}$M-DETA; In case of C3H female x ICR male embryos, the development rate was 41.0% at normal medium, but the rate was increased to 71.7% at 10 ${\mu}$M-EDTA-medium.

• Korean Journal of Acupuncture
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• v.28 no.3
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• pp.85-98
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• 2011

Objectives : The aim of this thesis is to examine the effect of acupuncture treatment at the GB37 on normal humans by using the power spectral analysis of the EEG. Methods : EEG (Electroencephalogram) power spectrum exhibits site-specific and state-related differences in specific frequency bands. In this thesis, the power spectrum was measured by the complexity. the 32 channels EEG study was carried out in the 13 subjects (12 males ; age=22.58 years old, 1 females ; 22 years old). Results : In the ${\alpha}$ (alpha) band, the power values at F7, F3, F4, F8, FTC2, C4, T4, CP1, CP2, TCP2, TT2, Pz, P4, Po1, Po2, O1, Oz, O2 channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. In the ${\beta}$ (beta) band, the power values at Cz, C4, T4, Tcp1, T6, Po1, O1, Oz, O2 channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. In the ${\delta}$(delta) band, the power values at Fp1, TT2 channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. In the $\theta$ (theta) band, the power values at Fp1, F8, FTC2, Pz channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. Conclusions : This results suggest that the acupuncture treatment at the GB37 significantly mostly change the power spectrum value on the alpha (18 channels), beta (9 channels) bands.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.81-88
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• 2015

To characterize the culture medium for the biosurfactant production by Bacillus pumilus IJ-1, the influences of various carbon, nitrogen and mineral sources were assessed. As a result, the highest biosurfactant production was observed after 96 h cultivation containing 0.5% (w/v) tryptone. The strain was able to grow and produce biosurfactant at 0-10% (w/v) NaCl, in the pH range of 5-10, and at $20-45^{\circ}C$. Optimal culture conditions for the biosurfactant production were at $20^{\circ}C$ and pH 9.0 after 72 h incubation and the surface tension of biosurfactant was 27.0 dyne/cm.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1266-1272
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• 2019

A bacterial strain, labeled $UR11^T$, was isolated from green alga Ulva pertusa collected from Jeju Island, Korea. $UR11^T$ was identified as a gram-negative, rod-shaped, motile by gliding and aerobic bacterial strain with yellow colonies on R2A plates. The strain $UR11^T$ grew over at a temperature range of $10^{\circ}C$ to $30^{\circ}C$ (optimally at $25^{\circ}C$), a pH range of 6.0-11 (optimally at pH 7.0) and a Nacl range of 0.5-5% Nacl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain $UR11^T$ was a member of the genus Flavobacterium. Strain $UR11^T$ shared close similarity with F. jejuensis $EC11^T$ (98.0%) F. jumunjinense $HME7102^T$ (96.1%), F. haoranii $LQY-7^T$ (95.3%), F. dongtanense $LW30^T$ (95.1%), and F. ahnfeltiae 10Alg $130^T$(94.9%). The major fatty acids (>5%) were $iso-C_{15:0}$ (33.9%), $iso-C_{15:1}$ G (12.4%), $iso-C_{17:0}$ 3-OH (9.0%), $isoC_{16:0}$ (7.0%) and $iso-C_{15:0}$ 3-OH (6.3%). The major polar lipids were phosphatidylethanolamine, seven unknown aminolipids, two unknown aminopolarlipids and two unknown lipids. DNA-DNA hybridization value was 58% at strain $UR11^T$ with F. jejuensis $EC11^T$. Based on phenotypic, chemotaxonomic and phylogenetic evidence, strain $UR11^T$ represents a novel species of the genus Flavobacterium, for which the name Flavobacterium jocheonensis sp. nov. is proposed. The type strain is Flavobacterium jocheonensis is $UR11^T$ (=KCTC $52377^T$ =JCM $31512^T$).

• Korean Journal of Microbiology
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• v.25 no.2
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• pp.148-156
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• 1987

Extracellular laccase (E.C. 1.10.3.2) from the culture filtrate of Pleurotus ostreatus was purified by ammonium sulfate precipctation, protamine sulfate precipitation, DEAE-Sephadex A-50 ion exchange chromatography and Sephadex G-100 gel permeation chromatography. The molecular weight of the enzyme was estimated by SDS-polyacrylamide gel electrophoresis to be 58,000 and the isoelectric point was 3.75. The optimum temperature for the enzyme was about $45^{\circ}C$ and the optimum pH was 6.5. The enzyme was found to be stable at temperature below $35^{\circ}C$ and rapidly inactivated at higher temperatures. Km values for ferulic acid, vanillic acid, dihydroxyphenylalanine (DOPA) were 48.6.$\mu$M, 0.52mM, and 2.73mM, respectively, which indicates that the enzyme has much higher affinity towards ferulic acid. The reaction products of the enzyme were separated by TLC and HPLC.

• KSBB Journal
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• v.5 no.1
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• pp.49-58
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• 1990

We constructed hybrid plasmids to allow controlled and extracellular production of human alpha-interferon in Escherichia coli. The hybrid plassmids were constructed by transferring alpha-lFN gene from plasmid Hif-2h which has the alpha-lFN gene at PstI restriction site of pBR322, to plasmids pIN -IIIB3 and pIN-IIIC3 at restriction sites between HindIII and BamHI. Plasmids pIN-IIIB3 and pIN-IIIC3 carry E. coli lipoprotein promoter, lac promoter and operator in tandem. The plasmids also have lacl genes which encode for lac repressors, which allows controlled expression of genes cloned to the plasmids by using of inducer IPTG. Lipoprotein signal sequence is located just ahead of cloning sites of the plasmids, which helps cells to excrete or secrete cloned gene products. Plasmid pUC9 was used as a intermediate vector for transferring of alpha-lFN gene from Hif-2h to pIN vectors in order to solve the problem of different restriction sites between Hif-2h and pIN vectors.

• Journal of Life Science
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• v.20 no.11
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• pp.1675-1682
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• 2010

The biological activity of hot water extract from Ecklonia cava Kjellman (ECE) was investigated to assess antioxidative, anti-skin aging, and nitrite scavenging abilities, as well as alcohol metabolizing activities. Antioxidant activity of ECE was measured by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity and superoxide dismutase (SOD)-like activity. DPPH radical scavenging activity and SOD-like activity of ECE increased in a remarkably dose-dependent manner, and were about 91.4% and 75% at 1 mg/ml, respectively. The xanthine oxidase inhibitory activity was indicated to be about 70% at 1 mg/ml of ECE. Nitrite scavenging ability of ECE showed to be 93.6% at 1 mg/ml and pH 1.2. The influence of ECE on alcohol metabolism was demonstrated through the generating activity of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH). The facilitating rate of ADH and ALDH activity by ECE was 167.2% and 334% at 10 mg/ml, respectively. In addition, tyrosinase and elastase inhibitory activities of ECE were 58% and 72% at 10 mg/ml, respectively. These results indicated that ECE has valuable biological attributes owing to its antioxidant, nitrite scavenging, alcohol metabolizing, and elastase and tyrosinase inhibitory activities.

• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.52-60
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• 1989

This study was carried out to know the possibility of simultaneous utilization of laccase from white-rot fungus with cellulase on enzymatic hydrolysis of cellulosic substrate from autohydrolyzed oak wood. Laccases from 3 white-rot fungi, Pleurotus ostreatus. Ganoderma lucidum, and Phanerochaete chrysosporium, were isolated, purified and measured their activities. The highest activity was shown in Pleurotus ostreatus and the lowest in Phanerochaete chrysosporium. Laccase from Pleurotus ostreatus has optimum pH of 5.94, Km value of 3.209 mM and appeared to be stable at relatively wide pH range, 4.7-8.72. Temperature stability showed that 60% activity was preserved after 40 minutes at $50^{\circ}C$. Laccase from Ganoderma lucidum reached to the maximum activity during 15-20 day incubation. This enzyme has optimum pH of 6.45, Km value of 6.71 mM and pH range of 5.0-9.0 for stabilization. 95% activity was preserved at $30^{\circ}C$ and 58% activity at $50^{\circ}C$. Concerned to the enzymatic hydrolysis of cellulosic substrate with both enzymes, cellulase and laccase, simultaneously, mixed culture filtrates and mycellium extracts were shown higher hydrolysis rates than those of Trichoderma viride. There were no significant differences in the extent of hydrolysis among various mixed culture filtrates and mycellium extracts.