• Journal of Life Science
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• v.24 no.8
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• pp.880-886
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• 2014

In this study, we isolate and identify bacteria from seawater collected from Jeju coast, to evaluate the antimicrobial activity against the fish pathogenic bacteria. 14 bacterial strains were isolated and identified using physiological, biochemical and molecular tools. Antibacterial activity of all the 14 isolates were screened against four major fish pathogens namely, two Gram-positive: Streptococcus iniae, Streptococcus parauberis and two Gram-negative: Vibrio anguillarum, Edwardsiella tarda. Results revealed that among the 14 isolates, MK-11 was found to have antibacterial activity against S. iniae, S. parauberis, V. anguillarum Particularly, S. iniae was susceptibility with the MIC value of $250{\mu}g/ml$. The biochemical and physio-chemical results reveal that MK-11 had the sugar-alcohol disassemble ability of the D-sorbitol and D-mannitol. Also the utilization of the yeast extract, sorbitol and di-potassium phosphate were noted to be high. The optimum culture condition such as pH and temperature was recorded as pH 6.0, $25^{\circ}C$ and along with 1% NaCl which differs from the previous reports particularly in nutrient resolutions. As results of the analysis of 16S rDNA sequences, MK-11 show the high similarity with Paenibacillus polymyxa, P. jamilae, P. brasilensis 99.78%, 99.43%, 99.39%, repectively. Hence, in the present study, the isolated Paemibacillus sp. MK-11 from Jeju seawater possesses the antibacterial activity against fish pathogens and it could be used as a new antibiotic agents against the gram positive fish pathogens.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1249-1256
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• 2017

In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as $cyclo-({\text\tiny{L}}-Val-{\text\tiny{L}}-Pro)$, $cyclo-({\text\tiny{L}}-Leu-{\text\tiny{L}}-Pro)$, $cyclo-({\text\tiny{L}}-Phe-{\text\tiny{L}}-Pro)$, $cyclo-({\text\tiny{L}}-Val-{\text\tiny{L}}-Phe)$, and N-(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus, with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.848-854
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• 2016

Cymbidium is one of perennial herbs belonging to the Orchidaceae and is known as a medicinal plant. However, its scientific data are insufficient. The purpose of this study is to extract from root and stem of Cymbidium, to investigate the biological effects of them. Cymbidium antibacterial effects of the extracts were performed by antibacterial test against Staphylococcus aureus (S. aureus), Staphylococcus saphrophyticus (S. saprophyticus), Proteus vulgaris (P. vulgaris) and Klebsiella pneumonia (K. pneumonia). Antioxidant effects of the extracts were carried out by DPPH radical scavenging. Total phenolic contents were also determined. Moreover, Cell viability of extracts against MTT assay was cell viability against HepG2 cell and also measures Cholesterol adsorptivity of extracts. In this study, the extracts inhibited the growth of bacteria. Particularly Cymbidium root extracts by only ethanol extraction showed highest antimicrobial effect against S. aureus. The Cymbidium stem extracts by both ethanol extraction and sonication for 1 hour had higher antioxidant activites as well as total phenolic contents. Cell cytotoxicity showed higher than $50{\mu}g/mL$. Cholesterol adsorptivity showed lower than 20%. These results suggest that the Cymbidium might be a source of anti-bacterials and anti-oxidants.

• Korean Journal of Veterinary Service
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• v.35 no.2
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• pp.119-128
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• 2012

This study was performed to investigate the freshness and nutritive components of eggs from Incheon area. The eggs of 64 brands collected from 7 hypermarkets and 6 brands collected from farms were examined to test the Haugh unit (HU), egg yolk index and specific gravity. HU and specific gravity were higher in farm eggs than in hypermarket eggs (P<0.05), and there was no difference in the egg yolk index. Among hypermarket eggs, HU and egg yolk index were higher in the graded eggs than in non-graded eggs (P<0.05), and specific gravity was not different between them. HU and egg yolk index of the eggs collected in March were higher than those in August (P<0.05). To monitor the bacterial contamination, total coliforms, total bacterial counts (TBC) and Salmonella enteritidis were examined. Salmonella enteritidis and total coliforms were not detected from all eggs. TBC of farm eggs were less than $10^1$ CFU/mL in all samples and TBC of hypermarket eggs were less than $10^1$ CFU/mL in 187 samples, $10^1{\sim}10^2$ CFU/mL in 3 samples and $10^3{\sim}10^4$ CFU/mL in 2 samples, respectively. Antimicrobial residues were not detected from all eggs tested. The vitamin E contents in the vitamin E enriched eggs from 6 brands hypermarket were 1.98~22.96 mg/yolk100 g ($14.04{\pm}8.81$ mg/yolk100g), and those of 5 brands among them were higher than the average of ordinary eggs. In one brand egg, vitamin E content was lower than the average of ordinary eggs. The vitamin E contents of ordinary eggs were 1.75~16.36 mg/yolk100 g (average $5.57{\pm}2.76$ mg/yolk100 g) and there were no price differences between vitamin E enriched eggs and ordinary eggs. In the contents of vitamin E, docosahexaenoic acid (DHA) and cholesterol, there were no significant differences according to the price. These results suggests that egg production, distribution, and management system should be improved for supplying fresh eggs to consumers at reasonable prices.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.168-173
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• 2000

Anticariogenic activity of the unripe apple extract was studied by observing the inhibitory effects on GTase(glucosyltransferase) activity, cell adherence and acid production of Streptococcus mutans. Among the four S. mutans strains, S. mutans MT 8148 had the highest water-insoluble glucan forming activity. (+)-Catechin and tannic acid, the major components of the unripe apple polyphenols inhibited GTase activity by 60% at 1 mg/ml and 90% at 5 mg/ml. Tannic acid and unripe apple extract inhibited adherence ability of S. mutans by 50% and 30%, respectively. But the acid production of S. mutans was not influenced by the polyphenols. Disc diffusion test showed that the polyphenols have no antimicrobial activity against S. mutans, which indicates that the inhibition of GTase activity and cell adherence were not resulted from the cell growth inhibition. Our results convinced the possible application of the unripe apple extract as the anticariogenic food additives.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.106-113
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• 2014

For the development of high value consumables utilizing jujube and grape, we investigated the biological activities of a variety of existing fermentation products of jujube and grape. The results revealed that ethanol fermentation products of jujube and grape had a higher antioxidative activity than acetic acid fermentation products. In addition, the ethanol fermentation products of jujube (JEF) had the highest antioxidative activity, with it being greater than that of the ethanol fermentation products of grape (GEF), the acetic acid fermentation products of jujube (JAF) and the acetic acid fermentation products of grape (GAF). As regards tests on whitening effects, JEF exhibited the highest tyrosinase inhibition effects amongst the test groups. However, when immunofluorecence was employed, JAF was seen to inhibit the expression of proteins related to the whitening effect. In the lipopolysaccharide-stimulated mode peritoneal macrophage model, all tested groups of fermentation products (JEF, GEF, JAF and GAF) suppressed nitric oxide production dose-dependently, with ethanol fermentation products demonstrating a higher nitric oxide expression inhibition effect than acetic acid fermentation products. When subjected to antibacterial activity tests, GAF exhibited antibacterial activity against all tested strains except Propionibacterium acnes. Both GAF and JEF revealed high antibacterial activity against Escherichia coli.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.47-53
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• 2015

Various diseases occur in fruits, leave and roots during strawberry cultivation and cause severe economical damage and huge amount of chemical fungicide use. Recently, as consumers' interest in safety of foods and organic agriculture produces have increased, control measures using alternatives for chemical fungicides have been newly developed in various ways. This study was conducted to test antifungal activity and control effect of sodium dichloroisocyanurate (NaDCC), using as disinfectants, against major disease pathogens of strawberry, Fusarium oxysporum (Fusarium wilt), Colletotrichum gloeosporioides (Anthracnose) and Phytophthora sp. (Phytophthora blight), and Xanthomonas fragariae (bacterial angular leaf spot) and evaluate availability as environment-friendly materials. When NaDCC was treated at the concentration range of 150 to 300 ppm, it suppressed significantly hyphal growth and reduced spore germination by more than 28%. In field condition, NaDCC showed excellent control effect (control value: 50%) against the bacterial angular leaf spot disease. Based on above-described results, we suggested that NaDCC can be used as alternative candidates to chemical pesticide alternatives of for controlling strawberry diseases.

• Korean journal of food and cookery science
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• v.25 no.4
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• pp.467-473
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• 2009

The principal objective of this study was to assess the quality characteristics of Topokki with different amounts of curry powder[0%(CT0), 2%(CT2), 4%(CT4), 6%(CT6) and 8%(CT8)], based on the amount of rice flour. The L values of the uncooked and cooked Topokki decreased significantly with increases in the amount of added curry powder. The a and b values of cooked Topokki increased significantly with increases in the amount of added curry powder. The weight gains(%) of CT0(11.40%), CT2(11.67%) and CT4(10.93%) were significantly higher and the volume increases(%) of CT2(12.53%) and CT4(12.23%) were higher than those of the other samples. Textural properties such as hardness, cohesiveness, springiness and gumminess were also assessed. Our sensory evaluation test demonstrated that the appearance of CT2(4.24), the color of CT2(4.24) and CT4(4.26), the flavor of CT2(4.34) and the overall acceptability of CT2(4.24) and CT4(4.26) were superior to those of the others. CT4, CT6 and CT8 evidenced more profound antimicrobial activities than the others. In conclusion, the addition of $2{\sim}4%$ curry powder to the rice flour proved the most acceptable for the preparation of Topokki with curry powder.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.2
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• pp.183-193
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• 2016

This study attempted to investigate the possibility of the use of Morinda citrifolia (MC) as a cosmetic ingredient from its physiological activities such as antioxidant activity, cytotoxicity and anti-aging effect. MC is a tropical plant that has been used as traditional polynesian foods and medicines for over two thousand years. It has been reported that this shrub can improve antimicrobial, anti-cancer and anti-inflammatory effects and strengthen an immune system. The in vitro antioxidant activity of MC was performed to see the DPPH scavenging activity by measuring total polyphenol content and total flavonoid content. As a result, a lack of any cytotoxicity was confirmed in human dermal fibroblasts (HDF) cell. When MC extract at a concentration of over $50{\sim}100{\mu}g/mL$ was added, MMP-1 expression considerably diminished. In an in vivo test, in addition, cream containing MC extract was prepared and applied to a total of 22 women in their 30 ~ 50s in ages in the morning and in the evening for four weeks. Changes in keratin, melanin index, pore, skin color and wrinkles under the naked eyes were then comparatively measured. Keratin levels slightly increased in the control group but decreased in the experimental group. In addition, wrinkles diminished in the experimental group. This study found that MC extract controls many MMP-1 related mechanisms with great potential for use as a natural ingredient of anti-aging cosmetics.

• Pediatric Infection and Vaccine
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• v.27 no.3
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• pp.147-157
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• 2020

Purpose: We investigated the trend of antibiotic susceptibility of Haemophilus influenzae over 5 consecutive years. Methods: We analyzed the antibiotic susceptibility of H. influenzae isolated from children aged <18 years, who were admitted to the Asan Medical Center Children's Hospital from March 2014 to April 2019. Antibiotic susceptibility of H. influenzae was determined by the disk diffusion test according to the European Committee on Antimicrobial Susceptibility Testing guidelines. Results: Excluding duplicates, 69 isolates were obtained over the past 5 years. The median age of the patients was 5 years (range, 2.8-8.6 years). The antibiotic susceptibility patterns were as follows: ampicillin (AMP)-susceptible/amoxicillin-clavulanate (AMC)-susceptible (AS/ACS; n=15 [21.7%]), AMP-resistant/AMC-susceptible (AR/ACS; n=21 [30.4%]), and AMP-resistant/AMC-resistant (AR/ACR; n=33 [47.8%]). The prevalence of isolates with AR/ACR phenotype tended to increase from 42.1% in 2014-2015 to 54.5% in 2018-2019 (P=0.342). Compared to 2014-2015, the resistance rates to cefuroxime and ceftriaxone in 2018-2019 increased from 31.6% to 77.3% and from 0.0% to 59.1%, respectively (P=0.003 and P<0.001, respectively). Conclusions: Over the last 5 years, H. influenzae isolates with AR/ACR phenotype and ceftriaxone resistance were frequently observed at our institute. The incidence of resistance to cefuroxime and ceftriaxone has increased significantly.