• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.3
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• pp.212-220
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• 2015

Purpose: Candida albicans can cause mucosal disease in many vulnerable patients. Also they are associated with denture-related stomatitis. Electrolyzed water is generated by electric current passed via water using various metal electrodes and has antimicrobial activity. The aim of this study was to investigate antifungal activity of electrolyzed water on C. albicans biofilm. Materials and Methods: C. albicans was cultured by sabouraud dextrose broth and F-12 nutrient medium in aerobic and 5% $CO_2$ condition to form blastoconidia (yeast) and hyphae type, respectively. For formation of C. albicans biofilm, C. albicans was cultivated on rough surface 6-well plate by using F-12 nutrient medium in $CO_2$ incubator for 48 hr. After electrolyzing tap water using various metal electrodes, the blastoconidia and hyphal type of C. albicans were treated with electrolyzed water. C. albicans formed blastoconidia and hyphae type when they were cultured by sabouraud dextrose broth and F-12 nutrient medium, respectively. Results: The electrolyzed water using palladium electrode (EWP) exhibited antifungal effect on blastoconidia of C. albicans. Also, the EWP significantly has antifungal activity against C. albicans biofilm and hyphae. In the electrolyzed water using various metal electrodes, only the EWP have antifungal activity. Conclusion: The EWP may use a gargle solution and a soaking solution for prevention of oral candidiasis and denture-related stomatitis due to antifungal activity.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.3
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• pp.323-328
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• 2019

Tuberculosis, a chronic bacterial infection caused by Mycobacterium tuberculosis (MTB), differs in its status latency and activity because of the characteristics of MTB, immune status of the host, and genetic susceptibility. The host defense mechanism against MTB is caused mainly by interactions between macrophages, T cells, and dendritic cells. CD44 is expressed in activated T cells when infected with MTB and regulates lymphocyte migration. In addition, CD44 mediates leukocyte adhesion to the ECM and plays a role in attracting macrophages and $CD4^+$ T cells to the lungs. Therefore, genetic polymorphism of the CD44 gene will inhibit the host cell immune mechanisms against MTB. This study examined whether the genetic polymorphism of the CD44 gene affects the susceptibility of tuberculosis. A total of 237 SNPs corresponding to the CD44 genes were analyzed using the genotype data of 443 tuberculosis cases and 3,228 healthy controls from the Korean Association Resource (KARE). Of these, 17 SNPs showed a significant association with the tuberculosis case. The most significant SNP was rs75137824 (OR=0.231, CI: 1.51~3.56, $P=1.3{\times}10^{-4}$). In addition, rs10488809, one of the 17 significant SNPs, is important for the tuberculosis outbreak can bind to the JUND and FOS transcription factors and can affect CD44 gene expression. This study suggests that polymorphism of the CD44 gene modulates the host susceptibility to tuberculosis in a variety of ways, resulting in differences in the status of tuberculosis.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.128-136
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• 2014

Acyl homoserine lactone (AHL) lactonase has been proved to be the AHL-degrading enzyme with the highest substrate specificity for AHL molecules and has shown a considerable potential as low-cost and efficient quorum quenching (QQ) technique. However, few studies focused on its inhibitory effect on biofilm formation which is also a quorum sensing (QS)-regulated phenomenon. In this study, QQ activity of six isolates from biofouled reverse osmosis membranes was studied using Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NTL4 as biosensors under various conditions. All of the isolates belonged to the genus Bacillus and showed QQ activity regardless of the acyl chain length or substitution of AHL molecule. The isolates were capable of significantly inhibiting biofilm formation (46.7-58.3%) by Pseudomonas aeruginosa PAO1 and produced heat-sensitive extracellular QQ substances. The LC-MS analysis of the QQ activity of a selected isolate, RO1S-5, revealed the degradation of N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C12 AHL) and the production of corresponding acyl homoserine (3-oxo-C12-HS), which indicated the activity of AHL lactonase. The broad AHL substrate range and high substrate specificity suggested that the isolate would be useful for the control of biofilm-related pathogenesis and biofouling in industrial processes.

• Journal of Life Science
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• v.21 no.10
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• pp.1428-1433
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• 2011

In this study, we isolated and characterized plant-associated lactic acid bacteria which are able to produce angiotensin-converting enzyme (ACE) inhibitory and antioxidative activities. Five lactic acid bacteria were isolated from plants (grape and leek), a plant-associated fermentative product (Kimchi) and Korean traditional alcohol (Dongdongju). Strains K-1 and K-21 from Kimchi, strain L-5 from leek, strain G-3 from grape, and strain D-3 from Dongdongju were identified as Pediococcus pentosaceus, Lactobacillus plantarum, Weissella cibaria, L. plantarum, and L. brevis, respectively, by 16S rRNA gene analysis. ACE inhibitory activities of isolated strains ranged from 44.3 to 71.9% in the MRS broth. G-3, L-5 and K-1 strains especially showed high ACE inhibitory activities (59.8-98.69%) in the MRS broth containing skim milk. DPPH radical scavenging activities of the strains were in the range of 42.5-82.7%. All strains showed varying levels of resistance in artificial gastric fluid (pH 2.5), retaining viability ranging from 42.2 to 88.1% after 3 hr of incubation. All strains showed high resistance to 0.3% oxgall after 24 hr of incubation; survival rates were in the range of 55.4-112.8%. Isolated strains were found to be antagonistic to some pathogens including Pseudomonas aeruginosa.

• Korean journal of applied entomology
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• v.19 no.3 s.44
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• pp.163-168
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• 1980

The antibiotic bacterium JS7901, one of the eighty three antibiotic microorganisms which have been is elated in the surburbs of CheongJu-city, showed the most effective antimicrobial activities against test organisms, both bacteria and fungi. Among the different culture media Soytone Sugar medium was the most effective for growth and activity of the JS7901 antibiotic bacterium a against both Escherichia coli and Staphyllococcus aureus by the cylinder plate method. The higher the sugar content, was, the greater the antibiotic amount of substances of JS7901 were produced in the soytone sugar media. The antibiotic bacterium, JS7901 appeared to have a broad activity spectrum showing inhibition in Vitro against gram positive and negative bacteria and plant disease fungi. In general, the active substances were not transferred into organic solvents. Only a small portion of the activity was transferred into ethyl ether and was also adsorbed to active carbon when the cultured broth was also adsorbed to active carbon when the cultured broth was at $pH\;2.0\~4.0$. On adjusting at pH 8.0, the activity disappeared. The crude active substances could be obtained by means of vacuum drying method and still shelved strong activity. The dried active rake was solved by solvents and crystallized into various shapes. The active substances were developed on the silica gel plate in the solvent system of n-butanol-acetic acid-water(3 : 1 : 1) and gave 5 pinkish colored spots when sprayed with $0.2\%$ ninhydrine in ethanol. The upper 5th spot, which was the result of using disc plate method with Escherichia coli was the strongest of these spots.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.222-226
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• 2011

Salmonellosis is a major bacterial zoonosis that causes self-limited enteritis to fatal infection in animals and food-borne infection and typhoid fever in humans. Multidrug-resistant strains of Salmonella spp. has increased over the last several decades and recently causes more serious problems in public health. The present study was investigated bacteriocidal effects of sodium chlorate, sodium azide, sodium cyanide, and sodium salts mixture containing sodium chlorate, sodium azide, and sodium cyanide on infection with S. typhimurium in macrophage RAW 264.7 cells, and antibacterial effects of sodium salts mixture for murine salmonellosis. In infection assay of S. typhimurium in RAW 264.7 cells, bacterial survival rates within macrophage in all treated groups was significantly reduced comparing to that of the control group with the passage of incubation time. Administration of sodium salts mixture showed a therapeutic effect for S. typhimurium infected ICR mice. The mortality of mice treated with sodium salts mixture was 70% until 12 days, while that of control mice was 100% until 9 days after S. typhimurium infection. The results of this study strongly indicate that sodium salts mixture has a potency treatment for murine salmonellosis.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.449-455
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• 2005

To reduce saft content of kochujang, various combinations of sub-materials such as ethanol mustard and chitosan were added to kochujang, and their effects on microbial characteristics, enzyme activities, and physicochemical characteristics of kochujang were investigated after 12 weeks of fermentation. Activities of ${\beta}$-amylase and pretense were low in ethanol-mustard-chitosan-added kochujang, whereas no significant difference was observed in ${\alpha$-amylase activity among all groups. Number of viable yeast cells decreased remarkably in mustard-added kochujang during late aging period, and anaerobic bacterial counts decreased in sub-material-added groups. Consistency of kochujang increased by addition of sub-materials, and oxidation-reduction potential was low in chitosan-added group. Mustard-chitosan-added kochujang showed lowest increase in total color difference(${\Dalta}E$) and decrease in water activity. PH of kochujang wns highest in mustard-chitosan-added kochujang, resulting in significantly increased titratable acidity. Addition of sub-material increased reducing sugar contents of kochujang, whereas ethanol production was significantly repressed in mustard-chitosan-added kochujang. Amino nitrogen content was Highest in mustard-chitosan-added kochujang during late aging period, whereas ammonia nitrogen content was lower in ethanol-mustard-added kochujang. Results of sensory evaluation indicated ethanol-mustard-added kochujang was more acceptable than other groups in taste and overall acceptability.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.275-282
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• 2009

The effect of two plant growth-promoting rhizobacteria (PGPR) on plant growth and systemic protection against soft rot disease and stem rot disease of canola (Brassica napus), caused by Erwinia carotovora and Sclerotinia sclerotiorum was investigated in a laboratory and a greenhouse. Selected PGPR strains C4 and D8 were treated to canola seeds by soaking. Strains C4 and D8 significantly not only increased plant height and root length about 74% and 40.3% and also reduced disease severity of soft rot disease by 80% by C4 and D8 respectively, compared to the control. Especially strain C4 showed antifungal activity against 6 fungal pathogens, S. sclerotiorum, Rhizoctonia solani, Botrytis cinerea, Fusarium oxysporum, Phytophthora capsici and Colletotrichum acutatum. In greenhouse experiment, the seed treatment of both of them increased plant height, leaf width and leaf length of canola plant to 19.5% and 24.9%, 11.3% and 15.3%, and 14.1% and 20.7% by C4 and D8, respectively, and reduced disease severity of S. sclerotiorium. These results indicate that these two PGPR strains can decrease disease severity and increased plant growth under greenhouse condition. Therefore, these two bacteria have a potential in controlling Sclerotinia stem rot of canola. These strains have to investigate under field condition to determine their role of antibiosis, induced systemic resistance and plant growth promotion on canola.

• The Journal of Natural Sciences
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• v.16 no.1
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• pp.15-29
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• 2005

To produce a thermostable cyclodextrin by using thermotolerant cyclomaltodextrin glucanotransferase(CGTase), a thermophilic and alkalophilic bacterium isolate, designated B-13 showing the highest CGTase activity was isalated from natural sources and identified as Bacillus cereus B-13 based on the morphological and physiological characteristics, and 16S rRNA sequence. The maximal CGTase activity (130 U/ml) was obtained when Bacillus cereus B-13 was cultured in SYC medium containing 2.0% soluble starch, 1.0% yeast extracts, 1% corn steep liquor and 1% $Na_2CO_3$ (pH 8.5) at $50^{\circ}C$ for 24 h and about 80% of maximal activity was also showed in he culture broth of $60^{\circ}C$ for 18 h. Optimum reaction temperature and pH of the partial purified CGTase for soluble starch were $65^{\circ}C$ and pH 8.5-9.0 respectively. The partial purified CGTase were also stable below $80^{\circ}C$ and pH 5.0-10.0. When 1% soluble starch was digested with the partial purified CGTase, the yield of cyclodextrin was 49%.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.99-108
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• 2013

Kefir is a unique fermented dairy product resulting from combined lactic acid and alcoholic fermentation of lactose in milk. Kefir is produced by the microbial activity of kefir grains. Kefir has numerous health benefits such as the reduction of cholesterol levels, stimulation of the immune system, antimutagenic and anticarcinogenic properties, and improvements of lactose intolerance. Furthermore, kefir is excellent as both a dietetic beverage and for protection against various diseases in small babies. Therefore, kefir has recently been regarded as an important functional dairy food. To date, the majority of research on kefir has focused on the applications of functional kefir using advanced biotechnology methods. The purpose of this review article is to facilitate the recognition of kefir as a novel functional food.