• Journal of Life Science
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• v.27 no.1
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• pp.57-66
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• 2017

Traditional Korean fermented herbal plants are potential sources of new food that promote health, but they are still produced by yeast, fungi or bacteria fermentation. In the present work, mushroom (Paecilomyces tenuipes and Cordyceps militaris) fungal dongchunghacho were used to fermented Glycyrrhiza uralensis Fischer (licorice) or mixed with pupa. The pupa were tested as solid substrates for the production of corcycepin, liquiritin, and liquiritigenin. The fermented substrates were analyzed the content of cordycepin, liquiritin, liquiritigenin, and glycirrhizin productivity and inhibitory activity of NO. The cordycepin content of 70% EtOH extract from the fermented mixture of licorice and 50% pupa with C. militaris increased maximum at 33 times. Pupa was very excellent for the production of cordycepin. The liquiritin content was decreased in all the assays inoculated with P. tenuipes and C. militaris dongchunghachos. The liquiritigenin content was higher when fermented with P. tenuipes than C. militaris. The addition of pupa significantly reduced the liquiritin content and glycyrrhizin production. As a result, the liquiritigenin content increased in fermented P. tenuipes and C. militaris, and liquiritin and glycyrrhizin decreased. The inhibition of NO production in the different ethanolic extracts fermented with licorice and pupa was also significantly increased and higher than that of a nonfermented extract in higher polar solvent extracts. The contents of cordycepin and biological active compounds were altered in accordance with the concentration of pupa and fungi. This study provides basic data for use in developing dongchunghacho fungi as a functional food resource.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.975-984
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• 2005

This study fulfilled to investigate the feed efficiency, tissue selenium distribution, carcass characteristic and economic value in finishing Hanwoo steers fed organic selenium mix (OSM) which included seleno-yeast, rumen culture and other microbial supplements. Forty five finishing Hanwoo steers were tested for 4 months dividing to three feeding groups: OSM add as 0.5 ppm Se of DM feeds (0.5 ppm OSM), OSM enriched add as 1.0 ppm Se of DM feeds (1.0 ppm OSM) and basal diet without OSM (control). The total weight gains, the average daily gains and the feed intakes were not differ in treatments (p > 0.05). No differences (p > 0.05) were noted for hot carcass weight, loin eye area, backfat thickness, meat yield index, meat color, fat color, tenderness and maturity. However, the 1.0 ppm OSM showed better performances for feed requirement, TDN per gain, meat yield grade and meat quality grade compared to other groups. Tissue selenium distribution was increased by organic selenium feeding: higher Se concentration in liver and rump of 0.5 ppm OSM (p < 0.05), and kidney, liver, sirloin and rump of 1.0 ppm OSM (p < 0.05) than the tissues of control group. Generally, tissue selenium was the highest value in 1.0 ppm OSM and showed higher concentrate in order; kidney, liver, sirloin and rump. The income over feed cost was 1.06-fold higher in 1.0 ppm OSM than control group. In conclusion, organic selenium mix supplementation and its amounts were not influenced to feed intake, body gain and carcass characteristic but significantly increased tissue selenium. Therefore, these results suggest that finishing Hanwoo steer fed an enriched organic selenium mix with proper probiotics is able to produce “high-Se” beef as high bioavailable form as well as create a beneficial opportunity on Hanwoo farm.

• Journal of Food Hygiene and Safety
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• v.31 no.1
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• pp.42-50
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• 2016

The effects of freezing and thawing conditions on microbiological quality and microstructure change of inoculated (Listeria monocytogenes and Campylobacter jejuni) and non-inoculated chicken breasts were investigated. Chicken breasts were frozen with air blast freezing (-20, -70, and $-150^{\circ}C$), ethanol ($-70^{\circ}C$) and liquid nitrogen ($-196^{\circ}C$) immersion freezing. There were no significant differences on the populations of L. monocytogenes inoculated with chicken breasts under different freezing conditions. However, air blast freezing ($-20^{\circ}C$) resulted in significant reductions for total aerobic bacteria and C. jejuni compared to the control and other freezing treatments. The frozen samples were thawed with (hot or cold) air blast, water immersion, and high pressure thawing at $4^{\circ}C$ and $25^{\circ}C$. the populations of total aerobic bacteria, and yeast and mold in the frozen chicken breast increased by 5.78 and 4.05 log CFU/g after water immersion thawing ($25^{\circ}C$) treatment. After five freeze-thaw cycles, the populations of total aerobic bacteria, yeast and mold, and C. jejuni were reduced by 0.29~1.40 log cycles, while there were no significant differences (P > 0.05) in the populations of L. monocytogenes depending on the freeze-thaw cycles. In addition, the histological examination of chicken breasts showed an increase in spacing between the muscle fiber and torn muscle fiber bundles as the number of freeze-thaw cycles increased. These results indicate that freezing and thawing processes could affect in the levels of microbial contamination and the histological change of chicken breasts.

• Culinary science and hospitality research
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• v.20 no.2
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• pp.100-119
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• 2014

In this study, rice was used with naturally fermented extract to compare and analyze the physico-chemical characteristics and investigated how to make pan bread made with domestic wheat flour added with naturally fermented rice extract. Also, it examined quality characteristics of pan breads prepared with 0, 10, 30, 50, 70% naturally fermented rice starters. As the fermentation time of rice starters increased, pH of bread doughs decreased. On farinograph, water absorption, development time and stability of rice starters samples were lower than the control. RVA(Rapid Visco Analyzer) analysis showed that wheat flour retrogradation was retarded by increasing rice starters content. The weights of pan breads containing rice starters were higher than that of control. The moisture content of pan breads containing rice starters decreased as storage time increased. In analyzing of visible mold colony during 7 days of storage at $28^{\circ}C$, pan breads containing rice starters was retarded mold growth. In the texture analyzer measurement, hardness of breads containing rice starters significantly increased as storage time increased, which was higher than that of control. The result of sensory properties was no significant difference between the group containing 50% naturally fermented rice starters and control group, such as appearance, flavor, taste and overall quality.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.369-376
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• 1997

These researches were carried out for improvement of medium for mycelial growth of Hericium erinaceus isolate KU-1. It grew well at pH 4 and $25^{\circ}C$. Glucose and sucrose were favorable carbon sources for mycelial growth. As nitrogen sources, ammonium acetate and arginine enhanced mycelial growth. Optimum C/N ratio was 200. Based On the results, the following recipe is suggested for synthetic medium for the mycelial growth: glucose 18.02 g, arginine 2.613 g, ammonium acetate 2.313 g, $CaCl_2\;0.33\;g$, $KH_2PO_4\;8.5\;g$, $MgSO_4{\cdot}7H_2O\;2.0\;g$, $FeSO_4{\cdot}7H_2O\;0.02\;g$, $ZnSO_4{cdot}7H_2O\;0.02\;g$, $MnSO_4{\cdot}7H_2O\;0.02\;g$, water 1 liter. This medium was superior for the mycelial growth to other conventional media such as Yeast malt extract agar (YMA), Park medium, Potato dextrose agar (PDA), Malt extract agar, Czapek-dox agar, Macaya-lizano medium and Yeast extract agar. This new synthetic medium is designated as Ko medium.

• Journal of Life Science
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• v.20 no.3
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• pp.403-410
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• 2010

In order to produce high-quality fermenting composts, a microorganism was isolated from the natural world. The bacterium has not only in high enzyme activities but also had good antimicrobial activities against phytopathogenic microorganisms. Its cultivating characteristics were then investigated. Bacterium KJ-9, which contains high CMCase, protease and chitinase activities and excellent antimicrobial activities against phytopathogenic microorganisms, was separated from leaf mold and identified as Bacillus licheniformis by two methods: Bergey's Manual of Systematic Bacteriology and API 50 CHL Carbohydrate Test Kit (Bio Merieux, France) using an ATB (Automated Identification) computer system (Bio Merieux, France). Optimal medium for cultivation of B. licheniformis was 2% soluble starch as a carbon source, 0.5% yeast extract as a nitrogen source and 0.05% $MgSO_4{\cdot}7H_2O$. Optimal growth conditions of pH, temperature and shake speed were pH 7.0, $50^{\circ}C$ and 180 rpm, respectively. Culture broth of B. licheniformis KJ-9 cultured for 36~60 hr was effective in fungicidal activities against plant pathogens including Botrytis cinerea, Corynespora cassicola, Fusarium oxysporum, and Rhizoctonia solani.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.773-778
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• 2004

Properties of wine produced from domestic grape, cultivar Campbell's Early, by carbonic maceration vinification process (CM) were investigated. Process required whole grape clusters without crushing or destemming and no yeast inoculation for fermentation. Fermentation heat was not generated. Yield of wine was 77%, close to that obtained by conventional process, 76%. Acidities of CM wines, free run and pressed wines, and conventional wine were pH 3.6 and 3.3, respectively. Tartaric acid contents of conventional, free run, and pressed wines were 1,813, 4,691, and 5,633 ppm, while those of malic acid were 3,446, 2,077, and 2,275 ppm, respectively. CM could reduce malic acid content by 2/3 that of conventional process. Both processes gave almost equal amounts of citric and acetic acids. CM wines had intense grape aroma and deep purple-blue, natural grape color.

• KSBB Journal
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• v.19 no.2
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• pp.118-124
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• 2004

Melanocytes synthesize melanin within discrete organelle termed melanosomes which are transferred to the surrounding keratinocytes and can be produced in varying sizes, numbers and densities. Skin whitening products have become increasingly popular in the past few years. The most successful natural skin whitening agents are: Arbutin, Vitamin C, Kojic acid, Mulberry, which are all tyrosinase inhibitors. In this work, melanoston, a melanogenesis inhibitor isolated from yeast was studied to understand its mechanism of melanogenesis inhibition. It was found that melanoston was not a tyrosinase inhibitor, while when melanoston was applied to the B16 melanoma cell culture media, the intracellular tyrosinase activity was decreased by more than 30％, When B16 melanoma was stimulated with ${\alpha}$-MSH, cell morphololgy was dramatically changed to have lots of dendrites on the cell membrane surface. On the other hand, B16 was treated with ${\alpha}$-MSH and melanoston, simultaneously, the change of cell morphology was not so great. This inhibition effect of melanoston was found to be related to the inhibition of intracellular activation and transportation of tyrosinase, which was observed by immunostaining of B16 melanoma using anti-tyrosinase antibody. From these results, melanoston was regarded as an inhibitor to the differentiation of melanoma cells.

• KSBB Journal
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• v.24 no.4
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• pp.334-340
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• 2009

For the isolation of a plant growth-promoting rhizobacteria, strain YK-5 was selected from approximately 400 thermostable strains isolated from special soil samples. Strain YK-5 produced an antifungal compound, and optimum carbon and nitrogen sources for the production of the antifungal compound were investigated against Aspergillus flavus as a test strain. Modified LB medium containing 1% peptone, 1% yeast extract and 5% black sugar was determined to be the optimal medium for growth and antifungal compound production. Culture broth of strain YK-5 potently inhibited growth of the phytopathogenic fungus Fusarium oxysporum KACC 40052 for 7 days. The plant growth-promotion function of strain YK-5 was tested against radish and rice in pot trials. Leaf number, plant height and root length in YK-5-treated radish markedly exceeded (> 60%) those of untreated radish. Leaf length and white rootlet development were markedly more prominent than in commercially-treated rice plants. Strain YK-5 was determined to be Bacillus subtilis YK-5 by physiological, chemotaxonomical, and phylogenetical analyses.

• Journal of Life Science
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• v.26 no.6
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• pp.646-650
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• 2016

The influence of chromosome number on cell growth and cell aging was investigated in various yeast strains that have many artificial chromosomes constructed using a chromosome manipulation technique. Host strain FY833 and the YKY18, YKY18R, YKY24, and YKY30 strains harboring 16 natural chromosomes, 18 chromosomes, 18 chromosomes containing rDNA chromosome, 24 chromosomes, and 30 chromosomes, respectively, were used, and the specific growth rate of each strain was compared. The specific growth rates in the YKY18 and YKY24 strains were indistinguishable from that in the host strain, while those of the YKY18R and YKY30 strains were reduced to approximately 25% and 40% of the host strain level, respectively. Subsequently, the replicative life span was examined to investigate the relationship between the number of chromosomes and cell aging, and the life span was decreased to approximately 14% and 45% of the host strain level in the YKY24 and YKY30 strains, respectively. Moreover, telomere length, well known as a senescence factor, was shorter and more diversified in the strain, showing decreased life span. Therefore, these results suggest the possibility that an increase in the number of chromosomes containing artificial chromosomes caused cell aging, and we expected these observations would be applied to improve industrial strain harboring of versatile and special artificial chromosomes.