• Asian-Australasian Journal of Animal Sciences
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• v.29 no.2
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• pp.211-218
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• 2016

This study evaluated the effect of Candida norvegensis (C. norvegensis) viable yeast culture on in vitro ruminal fermentation of oat straw. Ruminal fluid was mixed with buffer solution (1:2) and anaerobically incubated with or without yeast at $39^{\circ}C$ for 0, 4, 8, 16, and 24 h. A fully randomized design was used. There was a decrease in lactic acid (quadratic, p = 0.01), pH, (quadratic, p = 0.02), and yeasts counts (linear, p<0.01) across fermentation times. However, in vitro dry matter disappearance (IVDMD) and ammonia-N increased across fermentation times (quadratic; p<0.01 and p<0.02, respectively). Addition of yeast cells caused a decrease in pH values compared over all fermentation times (p<0.01), and lactic acid decreased at 12 h (p = 0.05). Meanwhile, yeast counts increased (p = 0.01) at 12 h. C. norvegensis increased ammonia-N at 4, 8, 12, and 24 h (p<0.01), and IVDMD of oat straw increased at 8, 12, and 24 h (p<0.01) of fermentation. Yeast cells increased acetate (p<0.01), propionate (p<0.03), and butyrate (p<0.03) at 8 h, while valeriate and isovaleriate increased at 8, 12, and 24 h (p<0.01). The yeast did not affect cellulolytic bacteria (p = 0.05), but cellulolytic fungi increased at 4 and 8 h (p<0.01), whereas production of methane decreased (p<0.01) at 8 h. It is concluded that addition of C. norvegensis to in vitro oat straw fermentation increased ruminal fermentation parameters as well as microbial growth with reduction of methane production. Additionally, yeast inoculum also improved IVDMD.

• Microbiology and Biotechnology Letters
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• v.10 no.4
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• pp.267-273
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• 1982

Among 12 kinds of ginsenosides in ginseng saponin, ginsenoside-Rb$_1$was contained the most abundantly. But ginsenoside-Rd which is similar to ginsenoside-Rb$_1$in structure, was known to be superior to ginsenoside-Rb$_1$pharmaceutically. In order to convert ginsenoside-Rb$_1$into ginsenoside-Rd by microbial enzyme treatment, a Rhizopus sp. was selected among various strais of molds found in rotten ginseng roots. Enzyme was prepared from the extract of wheat bran koji culture by ammonium sulfate precipitation (1.0 sat'd) and succeeding ammonium sulfate fractionation method (0.6-0.9 sat'd). For the purpose of use as substrate, saponins were purified by the several purification steps from alcohol extract of red ginseng roots. We obtained the total saponin which was composed of 36.5% of ginsenoside Rb$_1$, 12.2% of ginsenoside-Rd and other ginsenosides. For increase of ginsenoside-Rb$_1$ component ratio, we also obtained further purified ginsenoside-Rb group saponin containing 54.5% of ginsenoside-Rb$_1$, 1.1% of ginsenoside- Rd and other ginsenosides from purified the total saponin. In the enzymatic reaction system including the total saponin or the ginsenoside-Rb group saponin, we confirmed the specific conversion of ginsenoside-Rb$_1$to ginsenoside-Rd proportionally and no change of any other ginsenoside patterns by thin layer chromatography and high performance liquid chromatography.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.40-47
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• 2016

This study was conducted to evaluate the possible utility of 3 Aspergillus oryzae strains (designated as SCF-6, SCF-37, and JJSH-1), isolated from Korean traditional fermented materials, as starter cultures in the soybean paste industry. Doenjang (fermented soybean paste) was made with the A. oryzae strains described above, and its quality attributes were analyzed during a 60-day aging period. No significant differences in pH, moisture, or salt content were detected among the doenjang varieties made with the 3 Aspergillus strains. The concentration of amino-nitrogen, an indicator of doenjang aging, increased in each sample during the aging period. After the 60-day aging period, the contents of amino-nitrogen and free amino acid in doenjang made with SCF-6 showed the highest concentrations among the tested doenjang products: 971.6 and 8,064.9 mg%, respectively. Measurements of the color of doenjang showed that lightness and yellowness decreased during the aging period, but redness increased. After the 60-day aging period, the ${\gamma}$-aminobutyric-n-acid (GABA) concentrations in doenjang made with SCF-6 and SCF-37 were 61.3 and 53.7 mg%, respectively. In doenjang samples, aflatoxin was not detected and the concentrations of biogenic amines (histamine and tyramine) were 2.55-5.60 mg/kg and 3.70-5.87 mg/kg, respectively. These results indicated that A. oryzae SCF-6 isolated from traditional fermented foods could be useful as a starter culture in the soybean paste industry.

• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.7-13
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• 2016

As of many organochlorine pesticides, polychlorinated biphenyls are ubiquitous organic contaminants, which can be found in the most environmental matrices. Their toxic effects include endocrinedisrupting activity. Most researches with these toxicants performed with mixtures of congeners, namely Aroclor and related study has been done in complex environmental matrix, rather than single biosystems or pure congeners. 5 congeners were synthesized and their fates in pure microbial culture (Aspergillus niger) were determined in this study. Among biphenyl and synthetic congeners, biphenyl, PCB-1 (2-chlorobiphenyl), and PCB-3 (4-chlorobiphenyl) were rapidly transformed to hydrophilic metabolites, followed by PCB-38 (3,4,5-trichlorobiphenyl), while the degradation of PCB-126 (3,3',4,4',5-pentachlorobiphenyl) was not observed. The amounts of transformation for biphenyl, PCB-1, PCB-3, and PCB-38 were 65, 38, 52, and 2% respectively. The major metabolites of the above congeners were identified as mono- and di-hydroxy biphenyls, which are known to give adverse endocrinological effects.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.389-395
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• 2012

T-RFLP (terminal restriction fragment length polymorphism) analysis, one of the most highly adopted culture-independent microbial community analysis methods, was applied to evaluate the colonization of probiotics in experimental animal gut. Lactic acid bacteria that exhibited cinnamoyl esterase activity were isolated from Korean fermented vegetables and identified by 16S ribosomal RNA sequence analysis. Lactobacillus plantarum KK3, which demonstrated high chlorogenic acid hydrolysis by cinnamoyl esterase activity, and acid/bile salt resistances, was cultured, freeze-dried, and fed to mice and the microbiota in their feces were monitored by T-RFLP analysis. The T-RF of L. plantarum was detected in the feces of mice after the start of administration and lasted at least 31 days after the initial 7 day feeding. T-RFLP analysis was considered a useful tool to evaluate the gut colonization of probiotic L. plantarum. In order to prove that L. plantarum was from viable cells, we reisolated L. plantarum in the feces using cinnamoyl esterase activity media as the screening step. The colonization of L. plantarum KK3 in the mouse gut was confirmed by this research.

• Applied Biological Chemistry
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• v.24 no.2
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• pp.85-93
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• 1981

For the utilization of natural cellulosic materials by microorganisms, a potent cellulase-producing microorganism was isolated and identified as Trichoderma spp. Rice straw used as a substrate in this study was preliminarily treated with chemical solvents and/or additionally treated with acids and by heat, and then examined with the cellulase produced by the organism. Better results in sugar production by decomposing the straw cellulose were obtained, when the cellulase was produced by cultivating the organism in the selection medium, pH 5.0, for 5 days, and when the pretreated straw substrate was additionally treated with 0.1% $H_2SO_4$ sulfuric acid at $120^{\circ}C$ for 1 hour. The enzyme production was increased by about 20%, when 0.5% urea 0.5% phosphate, 0.1% meat extract, or 5% orange peel was added into the culture medium. For the practical purposes, the sugar production from the rice straw by the cellulase-producing microorganism can be improved by extending the reaction time of the enzyme up to 24 hr or longer.

• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.88-97
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• 2014

Objectives: The aim of this study was to evaluate the occurrence of microbiological contamination of kitchen utensils and environments of food service operations at university located in Seoul, Korea. Methods: We collected swab samples from the surfaces of knives, chopping boards, floors, and drains, as well as drinking water and airborne bacteria samples from 20 food service operations. Three bacterial indicators and five food poisoning bacteria were measured quantitatively and qualitatively, respectively. We used selective culture media and the PCR assay targeting 16S rRNA gene for the microbiological analysis. Results: We detected bacterial indicators on knives or chopping boards in eight different food service operations and, three food service operations (I, M, and O) showed more than 3 log colony forming units $(CFU)/100cm^2$ on their knives, significantly higher than the others. The levels of bacterial indicators on the floors and drains in the cooking areas were much higher than those on the cooking utensils. S. aureus was detected on 10 floors and 8 drains. Culturable bacteria were identified in 5 drinking water samples, and food service operation B ($431.1CFU/m^3$) and C ($551.2CFU/m^3$) showed more than $400CFU/m^3$ of total airborne bacteria. Conclusions: These results suggest that some of food service operations in this study may require additional investigation to secure the microbial safety of cooking environments. In addition, further actions including hygiene education for employees and proper guidelines to maintain clean cooking environments should be prepared.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.267-278
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• 1995

Human polymorphonuclear leukocytes(PMN) are the most numerous host cell in periodontal pockets and their presumed role is to form a protective barrier between the bacteria and periodontal tissues. Microbial component LPS activates macrophages to produce $IL-1{\beta}$, $MIP-1{\alpha}$, $-1{\beta}$, $TNF-{\alpha}$ and IL-6, etc. These cytokines have autocrine function to the macrophages, and paracrine function to other cell such as PMN and affect them to produce some biological functions. In the present study, human PMN were tested for the expression of $IL-1{\beta}$ and $MIP-1{\alpha}$ mRNA. Also we performed the receptor binding assay and in vitro assay for the antimicrobial action of HL-60 cell to determine whether HL-60 can replace the peripheral PMN in analyzing the biological functions. PMN were stimulated with $IL-1{\beta}$, TPA, $MIP-1{\alpha}$, LPS, IL-2 and total cytoplasmic RNA were extracted for the northern blot analysis. In order to determine the induction kinetics of $IL-1{\beta}$ or $MIP-1{\alpha}$ mRNA expression, cells were stimulated for 0,1,2,3 hours. We found peak expression of $IL-1{\beta}$ mRNA after 1hr of induction with $IL-1{\beta}$, LPS and after 2hr of induction with TPA. $MIP-l{\alpha}$ also induced but a scarce $IL-l{\beta}$ message from PMN. In contrast to the $IL-l{\beta}$ mRNA expression, $MIP-1{\alpha}$ were not induced from PMN in any culture conditions. Receptors for $MIP-1{\alpha}$ were identified on dibutyryl cyclic AMP(dbcAMP)-treated HL-60 as well as peripheral PMN. dbcAMP treatment significantly enhanced antimicrobial action of undifferentiated HL-60 cell. MIP-1 further increased enhancing effect of dbcAMP. $IL-1{\beta}$, to a lesser extent, also increased dbcAMP-induced enhancing effect of antimicrobial action of HL-60 cell.

• Korean Journal of Plant Tissue Culture
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• v.28 no.6
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• pp.297-304
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• 2001

Scrophularia buergeriana Misrule has been contaminated with various pathogens in condition of field and storage period. This study was carried out for production of multiple stress resistance plant containing disease resistance that CGST gene expressed in transgenic Scrophularia buergeriana Misrule genome. Glutathione S-Transferases (GSTs) detoxify endobiotic and xenobiotic compounds by covalent linking of tripeptide glutathione to hydrophobic substrate. GST enzymes have been identified and characterized in insects, bacteria, and many plant species. A cDNA clone of GST was introduced into Scrophularia buergeriana Miquel by transformation with Agrobacterium tumefaciences. In coporation of the CGST gene into S. buergeriana Misrule was confirmed by PCR analysis of genomic DNA. Influence of exposure to darkness on the regeneration potential and transformation frequence were assessed. The activity of GST in transgenic plants was two times higher than that of non-transgenic plants. As a result of anti-microbe assays, the crude extract protein of transgenic plants showed the antimicrobial effects higher than control plants.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.266-274
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• 2000

Understanding of microbial community structure in soil-root system is necessary to use beneficial soil and rhizosphere microbes for improvement of crop production and biocontrol. The knowledge of behavior and function of microbes in soil-root system plays a key role for the application of beneficial inocula. Because the majority of the intact bacteria in soil are unable to grow on nutrient media, both culturable and nonculturable bacteria have to be studied together. In our study, culture-independent survey of bacterial community in the soil-root system of red pepper fields was conducted by the sequence analysis of three universal clone libraries of genes which code for small-subunit rRNA (rDNA). Universal small subunit rRNA primers were used to amplify DNA extracted from each sample and PCR products were cloned into pGEM-T. Out of 27 clones sequenced, 25 clones were from domain bacteria. Two of the rDNA sequences were derived from eukaryotic organelles. Within the domain bacteria, several kingdoms were represented : the Proteobacteria (16 clones). Cytophyga-Flexibacter-Bacteroides group (2 clones). the high G+C content gram-positive group(1 clone) and 4 unknown clones.