• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.226-236
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• 2012

In the present work, the influence of prebiotic fructooligosaccharide (FOS) on adhesion to Caco-2 cells, viability, acid and bile tolerance, antibacterial, antioxidant, enzymatic, and metabolic activities of the probiotic starters Lactobacillus acidophilus GK20 and Lactobacillus paracasei GK74, has been explored. Experiments were conducted with fermented yoghurt over a period of 7 days at $4^{\circ}C$. When compared to control fermentations without prebiotic, the addition of FOS was seen to significantly (p<0.05) increase the viable cell counts of the probiotics, overall viscosity, and concurrently reduce the pH of the fermented yoghurts. Both Escherichia coli ATCC 11229 and Salmonella enteritidis ATCC 13076 were inhibited by the probiotics' antibacterial activities, while the synbiotic yoghurt containing mixed probiotics and FOS was noted to highly improve antagonistic action. When fermented with mixed starters, the addition of FOS (1.0%) resulted in the highest proteolytic ($1.06{\pm}0.06$ unit) and ${\beta}$-galactosidase activities ($20.14{\pm}0.31$ unit). However, FOS did not affect acid and bile tolerance, adhesion to Caco-2 cells or the antioxidant activity of the probiotics, although both L. acidophilus GK20 and L. paracasei GK74 had functionality as probiotic strains. Hence, a significant synbiotic effect was observed in fermented yoghurt after 7 days of storage at $4^{\circ}C$, and as a result, such synbiotic yoghurt can be said to possess synergistic actions which improve the gastrointestinal environment and promote of health.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.437-441
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• 2005

This study was investigated to compare the suppression of Meloidogyne arenaria by different treatments of Pasteuria penetrans which is known for biological control agent against Meloidogyne spp.. In order to select proper number of P. penetrans showing good suppression effect, P. penetrans were mixed with M, arenaria for attachment using three different concentration such as $3{\times}10^4$, $3{\times}10^5$ and $3{\times}10^6$ endospores/5 g medium, followed by treating them onto the roots of tomato. After 14 weeks incubation, P. penetrans at $3{\times}10^6$ endospores showed highest activity against the formation of gall caused by M, arenaria. At a dose of $3{\times}10^5$ endospores/5 g medium, P. penetrans was treated into soil either mixing with soil or spray onto soil surface for comparing of suppressive efficacy. When the antagonistic bacterium was treated by the former method, it suppressed more effectively Using P. penetrans at $3{\times}10^6$ endospores and mixing with soil method, suppression was compared among P. penetrans, $PASTORIA^{(R)}$(Japan) and $Fosthiazate^{(R)}$(Korea). P. penetrans was more potent than $PASTORIA^{(R)}$(Japan) and as similar as $Fosthiazate^{(R)}$(Korea). Therefore, these results suggested that P. penetrans can be used for controling of M. arenaria as biological control agent. Furthermore, thess results can be provided to develop environmentally-friendly nematicide.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.18-22
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• 2007

The optimum production condition for the antibiotic from Bacillus thuringiensis BK4 was determined, and the suppression rate of Fusarium-wilt by the butanol-extracted antibiotic was verified by employing tomatoes in vitro and in vivo pot tests. Cell growth and antifungal activity were the best when 0.5% xylose and 0.2% peptone No.3 were given as carbon and nitrogen sources, respectively, in the presence of 5mM $CaCl_2$. The partially purified antibiotic successfully prevented Fusarium oxysporum pathogen in pot experiments. When the pots were treated with both live cells and the partially purified antibiotic, an additive-effect was seen in the suppression of Fusarium-wilt, but synergistic effect was not detected. The antibiotic, denoted BK4, purified by Sephadex LH-20 column chromatography was eluted with a single peak at a retention time of 38 min. on prep-HPLC; Minimum inhibition concentration of the homogenous antibiotic was determined to be 50${\mu}$g/ml.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.23-28
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• 2007

Auxin-producing antagonistic bacterium K11, which can inhibit Phytophtora capsici, was isolated from a local red-pepper field soil in Gyeong-buk. In order to check for additional PGPR(plant growth promoting rhizobacterium) functions of the strain K11, we confirmed siderophore and cellulase productions by CAS (chrome azurol S) blue agar and CMC plate with congo red, respectively. The strain K11 was identified as Bacillus licheniformis with 98% similarity on 16s rDNA comparison and Biolog analyses. B. licheniformis K11 promoted mung bean adventitious root induction and enhanced root growth of mung bean (160%), pea (150%), and Chinese cabbage (130%), Also, B. licheniformis K11 was able to effectively suppress (63%) P. capsici causing red-pepper blight in the pot in vivo test. Therefore, we could select a triple-functional PGPR which has auxin, siderophore, and cellulase producing ability for effective crops production in organic farming.

• Research in Plant Disease
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• v.18 no.2
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• pp.109-116
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• 2012

A bacterial strain antagonistic to some fungal phytopathogens was isolated from the stem of a Persimmon tree in Yeongam, Korea. This bacterium was identified as Bacillus subtilis by 16S rRNA gene sequencing and designated as B. subtilis GDYA-1. In in vivo experiment, the fermentation broth exhibited antifungal activities against Magnaporthe oryzae on rice plants, Phytophthora infestans on tomato plants, and Puccinia recondita on wheat plants. We isolated one antifungal compound and its chemical structure was determined by mass and $^1H$-NMR spectral data. The antifungal substance was identified as benzoic acid. It inhibited mycelial growth of M. oryzae, Rhizoctonia solani, Sclerotinia sclerotiorum, and P. capsici with minimum inhibition concentration (MIC) values, ranging from 62.5 to 125 ${\mu}g/ml$. Moreover, the substance effectively suppressed Phytophthora blight of red pepper caused by P. capsici in a pot experiment. To the author's knowledge, this is the first report on the antifungal activity of benzoic acid against phytopathogenic fungi. Benzoic acid and B. subtilis GDYA-1 may contribute to environmental-friendly protect crops from phytopathogenic fungi.

• The Plant Pathology Journal
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• v.26 no.4
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• pp.386-393
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• 2010

In order to study disease resistance mechanisms in rice against the rice blast fungus Magnaporthe grisea, we screened fungal elicitor-responsive genes from rice suspension-cultured cells treated with fungal elicitors employing differential hybridization (DH). By DH screening, 31 distinct rice clones were isolated and a majority of them were full-length cDNAs encoding pathogenesisrelated (PR) genes. Sixteen of the 31 genes were upregulated at 4, 8, and 12 h following fungal elicitor treatment. To elucidate the effect of signal molecules and biotic elicitors on the regulation of rice defense genes, we further characterized the transcriptional expression patterns of representative isolated PR genes; OsGlu1, OsGlu2, OsTLP, OsRLK, and OsPR-10, following treatment with fungal elicitor, phytohormones, cycloheximide, and inhibitors of protein phosphorylation. Jasmonic acid (JA) induced transcriptional expression of OsGlu1, OsTLP, and OsRLK, but not of OsGlu2 and OsPR-10 at any of the tested time points. Salicylic acid (SA) and abscisic acid weakly induced the expression of OsTLP and OsRLK. SA showed an antagonistic effect with fungal elicitor and JA. Cycloheximide suppressed all these genes upon elicitor treatment, except for OsGlu2. Staurosporine only induced the expression of OsRLK. Application of calyculin A strongly induced OsRLK expression, but suppressed the expression of OsGlu2. Our study yielded a number of PR genes that play a role in defense mechanisms against the rice blast fungus, as well as contribute towards the elucidation of crosstalk between phytohormones and other modifications during defense signaling.

• Research in Plant Disease
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• v.14 no.1
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• pp.37-42
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• 2008

Bacillus subtilis BD0310 isolated from tea leaves was used for the development of a biofungicide against Pestitalotiopsis longiseta causing gray blight of tea plants. After mass culture of the antagonistic bacteria, the biofungicide formulated as a suspension concentrate was evaluated for its control efficacy against the gray blight of tea plant in a greenhouse and a tea plantation, respectively. Spray of the biofungicide 2 days before inoculation of P. longiseta inhibited more efficiently the development of gray blight compared with spray of the biofungicide 2 days after inoculation of the pathogen onto the leaves of tea plants in a greenhouse. In the field investigation under application of the biofungicide in 2005 and 2006, control efficiencies increased according to the number of spray of the biofungicide. Control efficiencies of the biofungicide were 52.4%, 66.7%, 71.4% and 85.7% against gray blight in 4 times spray of the biofungicide alone at 7 days interval, 6 times spray of the biofungicide alone at 7 days interval, 2 times alternate spray of biofungicide and chemical fungicide at 7 days interval and 4 times spray of chemical fungicide alone at 7 days interval, respectively. Therefore, the alternate application of the biofungicide and chemical fungicide at 7 days interval can increase the control efficiency with reduction of the amount of chemical fungicides and the number of spray for the control of gray blight of tea plants in the field.

• Research in Plant Disease
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• v.14 no.1
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• pp.43-50
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• 2008

Rhizoctonia blight (large patch) caused by Rhizoctonia solani AG2-2 is one of the major diseases on zoysiagrass in golf courses. In this study, anatgonistic bacteria to R. solani AG2-2 were selected in vitro tests using confrontation bioassay and triple layer agar diffusion method. The most active bacteria, Bacillus subtilis CJ-9 were tested for controlling large patch in pots. Relative Performance Indies (RPI) was used as a criterion for the selection of potential biocontrol agent. B. subtilis CJ-9 showed resistance to major synthetic agrochemicals used in golf course. In field tests at golf course, B. subtilis CJ-9 was more effective in suppression of large patch severity and population development of R. solani AG2-2 in soil than chemical fungicides. B. subtilis CJ-9 could be an alternative to chemical fungicides for eco-friendly management of large patch on zoysiagrass.

• Korean Journal of Poultry Science
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• v.21 no.4
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• pp.227-237
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• 1994

This study was conducted to investigate the interaction of vitamins A and E on their transfer from diet to chicken eggs and the effect of vitamin A flood-dosing on its concentration in eggs and livers. In Experiment I, forty-two 45-wk-old brown layers (Bobeock) were divided into seven groups and fed one of seven diets: control, three vitamin A supplemented diets(8, OOO, 16, 000, and 64, 000 IU /kg diet) or three vitamin E supplemented diets (50, 100, and 200 IU/kg diet). In Experiment II, a total of thirty-two 35-wk-old white layers (Hy-ine) were divided into four groups and fed one of four diets :control, vitamin A 20, 00O+vitamin E 200 TU /kg, vitamin A 50, O00+vitamin E 200 IU /kg or vitamin A 100, OO0+vitamin E 200 lU/kg supplemented diets. In Experiment III, a total of fifty-six 35-wk-old white layers (Hy-line) was divided into four groups and fed one of four diets: control or three vitamin A supplemented diets (80, 000, 120, 000 and 160, 000 lU/kg diet). In Experiment I, vitamin E levels of egg yolk in hens fed the vitamin A supplemented diets decreased as dietary vitamin A level increased (P

• Toxicological Research
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• v.27 no.4
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• pp.253-259
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• 2011

Transforming growth factor ${\beta}$ (TGF-${\beta}$) is involved in cellular processes including growth, differentiation, apoptosis, migration, and homeostasis. Generally, TGF-${\beta}$ is the inhibitor of cell cycle progression and plays a role in enhancing the antagonistic effects of many growth factors. Unlike the antiproliferative effect of TGF-${\beta}$, E2, an endogeneous estrogen, is stimulating cell proliferation in the estrogen-dependent organs, which are mediated via the estrogen receptors, $ER{\alpha}$ and $ER{\beta}$, and may be considered as a critical risk factor in tumorigenesis of hormone-responsive cancers. Previous researches reported the cross-talk between estrogen/$ER{\alpha}$ and TGF-${\beta}$ pathway. Especially, based on the E2-mediated inhibition of TGF-${\beta}$ signaling, we examined the inhibition effect of 4-tert-octylphenol (OP) and 4-nonylphenol (NP), which are well known xenoestrogens in endocrine disrupting chemicals (EDCs), on TGF-${\beta}$ signaling via semi-quantitative reverse-transcription PCR. The treatment of E2, OP, or NP resulted in the downregulation of TGF-${\beta}$ receptor2 (TGF-${\beta}$ R2) in TGF-${\beta}$ signaling pathway. However, the expression level of TGF-${\beta}1$ and TGF-${\beta}$ receptor1 (TGF-${\beta}$ R1) genes was not altered. On the other hand, E2, OP, or NP upregulated the expression of a cell-cycle regulating gene, c-myc, which is a oncogene and a downstream target gene of TGF-${\beta}$ signaling pathway. As a result of downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc, E2, OP, or NP increased cell proliferation of BG-1 ovarian cancer cells. Taken together, these results suggest that E2 and these two EDCs may mediate cancer cell proliferation by inhibiting TGF-${\beta}$ signaling via the downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc oncogene. In addition, it can be inferred that these EDCs have the possibility of tumorigenesis in estrogen-responsive organs by certainly representing estrogenic effect in inhibiting TGF-${\beta}$ signaling.