• The Korean Journal of Zoology
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• v.29 no.3
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• pp.215-233
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• 1986

The effect of tryptophan on brain formation at the early stage of chick embryo has been investigated morphologically using electron microscope. The electron micrographs of cerebral cortex cells of $5\\sim10$ day old chick embryo, which received 1.0mg of tryptophan showed that the irregularity, evagination and disruption of nuclear membrane and nuclear chromatin condensation, nucleolar chromatin margination and segragation. Hypertrophy of stalks, vesicles, and vacuoles can be seen and dilation and vesiculation of rough endoplamic reticulum and polysome disaggregation occured. Protein and RNA levels and the activity of several enzymes such as lactate dehydrogenase, succinate dehydrogenase, malate dehydrogenase and glucose 6-phosphate dehydrogenase of tryptophan administered group were significantly lower than those of control group suggesting that the tryptophan administration depressed protein biosynthesis resulting in the decrease of enzyme activity. It was found that serotonin content of egg yolk which has been incubated for 10 days were as much as three times that of control egg yolk. It is not clear whether the increase of serotonin content might inhibit intracellular yolk granule degradation which might result in malformation of chick embryo, but it is likely that tryptophan administration might depress protein biosynthesis, consequently, the enzyme biosynthesis would be impaired. This might give rise to improper development of chick embryo.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.268-273
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• 1996

An extremely cadmium tolerant yeast, Hansenula anomala B-7 used to determine the modification of the intracellular enzyme activities by cadmium ion. The activities of alcohol dehydrogenase, phosphofructokinase, and cytidine deaminase were decreased up to 90%, 40%, and 86% compa- red with the control by 1 mM cadmium nitrate respectively, but the activities of malate dehydrogenase, 6- phosphogluconate dehydrogenase, cytochrome c oxidase, and alkaline phosphatase were increased up to 440%, 136%, 260% and 155% compared with the control by 1 mM cadmium nitrate respectively. These results show that the activities of the enzymes participating in Embden-Mayerhof pathway (e.g. anaerobic metabolism) were reduced by cadmium, but those involved in hexose monophosphate pathway and tricarboxylic acid cycle (e.g. aerobic metabolism) were stimulated in contrast. It has been suggested that the diminished activity of cytidine deaminase in pyrimidine nucleotide dissimilation occured due to the inhibited nucleotide dissimilation by cadmium ion; the enhanced activity of cytochrome c oxidase was specifically required in order to oxidize a raised amount of NADH and NADPH due to the increased aerobic metabolism.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.301-307
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• 1998

Intraspecific and interspecific isozyme variations and their relationship of 16 local populations in 3 species of Phyllostachys, that is, P. bambusoides, P. nigra var. henonis and P. pubescens were investigated by multi-variate analysis. Leaf isozymes of Phyllostachys such as 6-PGD (6-phosphogluconate dehydrogenase), MDH (malate dehydrogenase), PGI (phosphoglucoisomerase), PRX (peroxidase), PGM (phosphoglutamase), IDH (isocitrate dehydrogenase) showed electrophoretic variations in the number of zymotypes (7, 6, 6, 9, 3 and 5, respectively). In the cluster analysis on the isozymic characteristics, 16 populations were classified into 3 species at the euclid genetic distance of 2.041. P. nigra var. henonis and P. bambusoides were clustered first at 2.813 and then P. pubescens at 3.001. So far, 3 local types of intraspecific ariation were found in P. nigra var. henonis and P. bambusoides.

• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1908-1914
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• 2008

An alkaliphilic bacterium, Bacillus clausii SKAL-16, was isolated from soil that had been contaminated with vegetable oil. The optimal pH and general pH range for bacterial growth was 8, and 7 to 10, respectively. The bacterium could grow on tributyrin and glycerol, but could not grow on acetate and butyrate. The SKAL-16 strain excreted butyric acid during growth on tributyrin, and selectively ingested glycerol during growth on a mixture of butyric acid and glycerol. The SKAL-16 generated intracellular lipase, but did not produce esterase and extracellular lipase. The DNA fragment amplified with the chromosomal DNA of SKAL-16 and primers designed on the basis of the esterase-coding gene of Bacillus clausii KSM-KI6 was not identical with the esterase-coding gene contained in the GenBank database. Pyruvate dehydrogenase, isocitrate dehydrogenase, and malate dehydrogenase activities were detected in the cell-free extract (crude enzyme).

• The Korean Journal of Mycology
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• v.17 no.1
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• pp.35-38
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• 1989

Gene libraries of DNA from Flammulina velutipes were constructed using Escherichia coli plasmid pBR 322. Leu 2 gene coding ${\beta}-isopropylmalate$ dehydrogenase from F. velutipes was cloned by complementation of leucine requiring mutant of E. coli. The size of inserted DNA fragment of this clone is about 1 Kbp. The fragment has Bam H1 and Ava 1 restriction sites.

• The Korean Journal of Mycology
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• v.17 no.1
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• pp.27-30
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• 1989

F. velutipes Leu 2 gene (${\beta}-isopropylmalate$ dehydrogenase gene) was used for transformation of P. florida leucine requiring auxotrophic mutant P101. Transformation frequency was very low but the transformed colony can grow on minimal medium very slowly. Transformation was identified by Southern hybridization and reverse transformation into E. coli using chromosome DNA isolated from transformed P. florida.

• The Korean Journal of Malacology
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• v.14 no.1
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• pp.33-40
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• 1998

A horizontal starch gel electrophoresis for enzyme proteins extracted from 2 species of Korean viviparid snails; Cipangopaludina chinensis malleata and C. japonica was carried out in order to elucidate their genetic relationships. A total of 10 enzymes were employed in three different kinds of buffer systems. Two loci from each enzyme of alcohol dehydrogenase, esterase, glucose phosphate isomerase, isocitrate dehydrogenase, iditol dehydrogenase, malate dehydrogenase and peptidase(VL); and only one locus dach from two enzymes, glycerlo-3-phosphate dehydrogenase and phosphoglucomutase were detected; but, four loci from peptidase(LGG) were observed. Most of loci in two viviparid species showed homozygous monomorphic banding patterns and some of them were specific as genetic markers between two different species. However, EST-1, MDH-1, PEP(VL)-1loci showed polymorphic banding patterns. Foru populations of C. chinensis malleata were more closely clustered in a dendrogram within the range of genetic identity values of 0.928-1.00, and these clusters were lineated with C. japonica at the value of 0.355. In summarizing the above results, two viviparid snail species dmployed in this study mostly showed monomorphic enzyme protein banding patterns, and genetic differences specific between two species.

• Microbiology and Biotechnology Letters
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• v.8 no.4
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• pp.221-227
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• 1980

The presence of L-malic acid in culture media contaniing glucose stimulated the growth rates of Leuconostoc oenos strains. The L-malic acid also stimulated the synthesis and activity of D-malate dehydrogenase (D-LDH) resulting in rapid production of D-lactate from glucose. The rapid utilization of glucose under the presence of L-malic acid may explain, in part, the stimulatory effect of the compound on the growth rate of leuconostocs.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.985-990
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• 1995

Grapefruit seed extracts(GFSE) have some unknown compounds which exhibit the antibiotic activities aganist microorganisms including bacteria and fungi. We have examined the effects of GFSE on the growth of Enterobacter pyrinus which was isolated from necrotic lesions of pear trees. During the cultivation, the growth of the bacteria was strongly inhibited at the low concentration(0.01%, w/w) of GFSE. Hydrophobic fraction extracted from GFSE by mixed solvents (chloroform : methanol : water, 1 : 2 : 0.8, v/v/v) had components which inhibited the growth of bacteria. There was, however, no inhibitory effect of GFSE on the activities of several enzymes including hexokinase, glucose 6-phosphate dehydrogenase, malate dehydrogenase and succinate dehydrogenase. $O-nitrophenyl-{\beta}-D-galactopyranoside(ONPG)$, the artificial substrate of ${\beta}-galactosidase$ was hydrolyzed in the presence of GFSE, indicating that the membrane was pertubated by the GFSE. From the results it was suggested that the antibiotic activity of GFSE is due to the change of membrane permeability of cell. GFSE was fractionated by high performance liquid chromatography equipped with $C_{18}$ reverse phase column. Among active fractions, three peaks were identified as 1-chloro-2-methyl-benzene (o-toluene), N,N-dimethyl-benzenemethaneamine, 1-[2-(2-ethylethoxy)ethoxy]-4- (1,1,3,3-tetramethyl)-bezene, respectively, while the other three remained unidentified.

• Food Science and Preservation
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• v.14 no.3
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• pp.323-327
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• 2007

Moderate consumption of maesil(Prunus mune) was associated with pharmaceutical and physiological effects on human health. The object of this study was to determine the inhibitory effects of Prunus mune extracts(PME) on food spoilage microorganisms. PME was found to have an antibacterial effect on Colletotrichum fragariae. The hydrophilic fractions of PME showed more effective inhibition than did the hydrophobic fractions. In addition, the hydrophilic fractions of PME seemed to inhibit(12-40%) metabolic enzymes related to energy production, including glucose-6-phosphate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, and hexokinase. Our data suggest that hydrophilic components of PME might control food spoilage microorganisms because of suppression of membrane enzymatic function.