• Korean Journal of Microbiology
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• v.49 no.2
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• pp.156-164
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• 2013

Actinomycetes produce diverse secondary metabolites which have the primary importance in medicine, agriculture and food production, and key to this is their ability to interact with other organisms in natural habitats. In this study, we have investigated the taxonomical and functional diversity of actinomycetes in fecal sample of rhinoceros beetle larvae (Allomyrina dichotoma L.) by using culture-dependent and -independent approaches. For the culture-independent approach, the community DNA was extracted from the sample and 16S rRNA genes of actinomycetes were amplified using actinomycetes-specific PCR primers. Thirty-seven clones were classified into 15 genera and 24 species of actinomycetes. For the culture-dependent approach, 53 strains were isolated from larval feces, of which 27 isolates were selected based on morphological characteristics. The isolates were classified into 4 genera and 14 species, and 24 isolates (89%) were identified as the genus Streptomyces. Many of the representative isolates had antimicrobial activities against plant pathogenic fungi and Gram-positive bacteria. In addition, most of the isolates (78%) showed biochemical properties to hydrolyze cellulose and casein. The results demonstrated that diverse and valuable actinomycetes could be isolated from insect fecal samples, indicating that insect guts can be rich sources for novel bioactive compounds.

• Journal of Life Science
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• v.22 no.2
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• pp.259-265
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• 2012

A bacterial strain, CK214, exhibiting high motility on an LB agar (1.5%, w/v) surface was isolated from the environment. The formation of unusual agar shrinking around colonies on agar plates was observed. The strain grew on minimal media containing pure agar as a sole carbon source. The cell-free culture supernatant of CK214 generated a reduced form of sugar in the in vitro reaction with the use of pure agar as a substrate, suggesting the secretion of an agar-degrading enzyme. The CK214 strain showed swarming motility on the solid media containing a wide range of concentrations of agar (0.5, 1.0, 1.5, 2.0% w/v). Various tests, including Gram staining, API analysis, and phylogenetic analysis based on 16S rDNA sequences identified that the CK214 strain was a G(+) rod-shaped bacterium grouped in genus Paenibacillus. Electron microscopic analysis demonstrated that the P. CK214 strain is peritrichously flagellated. Through transposon random mutagenesis, several agar-degrading activity defective mutants (ADMs) were generated. These mutants will be used in the future experimentation for the study of the correlation between agar-degrading activity and motility.

• Horticultural Science & Technology
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• v.16 no.1
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• pp.21-24
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• 1998

RAPD markers were analyzed in order to detect the genetic variation and diversity of the fifty-two melon lines. SDS extraction method produced more and purer DNA than CTAB method. RAPD reaction conditions were optimized as follows ; 10ng template DNA, 270nM primer, $200{\mu}M$ each of dATP, dCTP, dGTP and dTTP, $0.3{\mu}unit$ dynazyme and 10x buffer brought to $15{\mu}l$ final volume with distilled water. The adequate annealing temperature was $39^{\circ}C$ and forty cycles of amplification produced the best RAPD band patterns. Among a total of 123 bands from 12 random primers, 25 polymorphic bands(20%) were selected as reliable markers. The average number of polymorphic bands per primer was 2.1 among the 52 lines. Intragroup genetic relationship based on the marker difference was closer than intergroup genetic relationship. The 52 lines could be grouped into two major group (Korean landraces and melon lines) and then melon group subdivided into two subgroups (net melon lines and no-net melon). This result corresponded to morphological grouping. Eight RAPD markers separated the Korean landraces and melon groups and four RAPD markers separated net melon and no-net melon groups.

• Journal of Mushroom
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• v.8 no.4
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• pp.150-156
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• 2010

This study was carried out to investigate the physiological activities of the ethanol extracts from 11 strains of Flammulina velutipes. In addition, the ${\beta}$-glucan and polyphenol contents were also measured. The contents of polyphenol and ${\beta}$-glucan of Flammulina velutipes were found to be more than 100 mg% and 20%, respectively, one of which showed 244.74 mg% and 27.37%, respectively. Further, The highest inhibitory activities on DPPH radical, ${\alpha}$-amyloglucosidase activity and nitric oxide production were 91.74%, 63.57% and 61.44%, respectively. However, ethanol extracts from all the strains have little effects on Angiotensin I converting enzyme(ACE)-inhibitory effects. Finally, the highest cytotoxic activities of ethanol extracts from all the strains on A549 and HT-29 cell were 76.07% and 67.05%, respectively.

• Journal of Life Science
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• v.24 no.11
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• pp.1174-1179
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• 2014

This research was carried out to evaluate whether gamma ray is a useful tool for breeding new strains of mushrooms. For this research, 5 mutant groups, 20 strains of Hypsizigus marmoreus, 2 strains of Lyophyllum decastes, and 1 strain of Lyophyllum shimeji were used. Monokaryon spores from one variety of H. marmoreus were irradiated with 50~2,000 Gy of gamma ray. The propriety dose was 50~200 Gy for mutagenesis. Mutant monokaryon mycelia crossed each order to become dikaryon mycelia. The internal transcribed spacer (ITS) regions of rDNA were amplified using PCR, and the products were sequenced. The sequences of the ITS regions (16 partial rDNA, complete ITS1, 5.8 rDNA and partial rDNA) were analyzed by PCR, and strains of H. marmoreus, L. decastes, and L. shimeji were auto-sequenced. The lengths of the sequenced ITSs were 1,052~1,143 nucleotides. Genetic matrices were calculated using Nei-Li's genetic distance coefficient based on ITS sequence. The dissimilarities were 0~3.35% in strains of H. Hypsizigus. In addition, a phylogenetic tree was constructed based on ITS sequences using the neighbor-joining (NJ) method. The phylogenetic tree revealed that 23 strains and 5 mutant groups were divided into 12 clusters; the mutant groups fell into different clusters. These results show that mushroom spores were mutated effectively by gamma ray; therefore, gamma ray could be a useful tool for breeding new strains of mushrooms.

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.226-234
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• 2000

Protective effect of Corydalis ternata against the carbon tetrachloride-induced toxicity was investigated. Carbon tetrachloride($CCl_4$) induces hepatotoxicity due to the reactive free radical(CCl$_3$ . ) generated by cytochrome P-450 enzyme. We examined effects of hexane, chloroform, butanol and water fractions prepared from the Corydalis ternata methanol extract. Rats were treated with those for 3 days, and liver microsomes and cytosols were prepared at 24 hour after last treatment. Hepatoprotective activity of the water fraction was higher than that of other fractions. To examine mechanism of the hepatoprotective effect of Corydalis ternuta, we measured contents of malondialdehyde(MDA), cytochrome P46O(CYP), glutathione, calcium as well as the activities of NADPH-CYP reductase, glutathione S-transferase(GST), superoxide dismutase(SOD), glutathione peroxidase(GPX) and catalase. The fraction inhibited production of MDA, content of CYP and calcium in liver of water fractions - treated rats as compared with those of CCl4-treated rats. The GST activity was increased. We speculate that the O2 radical scavenging activities of the water fraction might play a key role in the mechanism opposing the progression of $CCl_4$-induced hepatotoxicity, but the activities of SOD, GPX, CAT were decreased. These results suggest that the mechanism might be mainly due to the decrease of CYP contents, act as calcium channel blocker and increase of GST activity rather than $O_2$ radical scavenging activities.

• Korean Journal of Poultry Science
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• v.19 no.1
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• pp.47-53
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• 1992

This study was carried out to determine the plasma vitamin $D_3$($D_3$) of 3 weeks old broiler chicks (Hubbard line), whose dorsal skin was exposed to different dose of 310 m UV light. The irradiated doses were 0~0.79 J/$\textrm{cm}^2$(6 doses$\times$5 replica＝30 chicks). The blood samples were collected 2 days after exposure. The lipid in plasma isolated was extracted with ethyl acetate. The $D_3$ was purified by $C_{18}$ cartridge and analyzed by HPLC. The average $D_3$ content in plasma of control chicks was 20 ng /$m\ell$. When 0.32 J/$\textrm{cm}^2$ of dose was treated, the highest amount of 43 ng /$m\ell$ was found among those of chicks experimented, corresponding to 2.15 times that of control. However, When more doses than 0.32 J/$\textrm{cm}^2$ were exposed to the skin, D$_3$ contents were decreased gradually. The similar to control level of $D_3$ was observed when 0.79 J/$\textrm{cm}^2$ was applied.

• Analytical Science and Technology
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• v.16 no.2
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• pp.152-158
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• 2003

This study was conducted to evaluate two sample digestion procedures and instrumental determination parameters for analysis of lead in bone. Amputated human legs were treated by acid digestion or microwave dissolution prior to spectrometric analysis. Inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GF-AAS) were used for determining bone lead levels. Recovery efficiencies using standard reference material from acid digestion measured by ICP-MS were in good agreement with those of the certified value, but in cases of acid digestion by GF-AAS and microwave digestion by both two methods, recovery underestimated and overestimated, respectively. For the bone samples, the lead concentrations obtained by ICP-MS after acid digestionwere in good agreement with those by GF-AAS (correlation coefficient = 0.983), but GF-AAS gave systematically higher values than ICP-MS. While a good agreement between two analytical methods after microwave digestion was also obtained (correlation coefficient = 0.950), bone lead concentrations from microwave were relatively higher than those from acid digestion. In conclusion, the use of the simple nitric acid digestion procedure at an ambient temperature coupled to ICP-MS seems to be efficient for the determination of lead in bone in consideration for both the convenience and validity.

• Applied Biological Chemistry
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• v.29 no.2
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• pp.122-129
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• 1986

The lipid compositions of corns produced in Korea were analyzed. Free and bound lipids of the corn kernels were fractionated, quantitated and compared by silicic acid column, thin layer and gas liquid chromatography. Corn kernels contained 5.02% total lipids, which is consisted of 4.09% free lipids and 0.93% bound lipids. Free lipids comprised of 89.61% neutral lipids, 3.75% glycolipids and 6.40% phospholipids, while bound lipids contained 14.26% neutral lipids, 46.06% glycolipids and 37.18% phospholipids. In the neutral lipids of free lipids, triglycerides were predominant (67.68%) and minor components such as esterified sterols, free sterols, free fatty acids, 1,3-diglycerides, 1,2-diglycerides were present. But in the neutral lipids of bound lipids, esterified sterols were not present and the contents of triglycerides were lower (47.68%) and free fatty acids were higher than those of free lipids. Among the phospholipids in free and bound lipids, phosphatidyl choline and phosphatidyl serines and phosphatidyl inositols were also present as minor components. The major fatty acids in the three lipid classes were linoleic, oleic and palmitic acids.

• Journal of agricultural medicine and community health
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• v.24 no.2
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• pp.369-385
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• 1999

This is carried out to study on the general consciousness for medical ethics of Korean local and hospital clinicians from March to May, 1999. The subjects are 288 respondents out of 1,500 those who selected by systemic random sampling method from the list of physicians published on 1997. An adequate questionnaire with 21 questions made by author was distributed through mail for those. The characteristics of respondents are as follows. Women are 15%. For like this questionnaire, those who were graduated from. The national universities were more actively concerned than those graduated from the private universities. Christian was 35.4%, Catholic was 28.5% and buddhist was 14.9% and 17.4% had no religion. Now a day in generally, it is clearly confusing status between an ideal thinking and actuality in medical ethical aspects in Korea. They want more developed medical delivery system. The most of physicians are improving on four mind-sets, the mind of love, pity, joy and abandonment as much as they are cognizing that the pains of patients are themselves pains. But they do not want to be the ministry. On the problems of the easy to die, it seems that they have somewhat different opinions according to their religions, respectively;- christians are more responsible than others to keep to the terminal point of life of patients.