• The Plant Pathology Journal
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• v.25 no.4
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• pp.344-351
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• 2009

A biocontrol bacterium Bacillus licheniformis N1 grown in nutrient broth showed no chitinolytic activity, while its genome contains a gene which encodes a chitinase. The gene for chitinase from B. licheniformis N1 was amplified by PCR and the deduced amino acid sequence analysis revealed that the chitinase exhibited over 95% identity with chitinases from other B. licheniformis strains. Escherichia coli cells carrying the recombinant plasmid displayed chitinase activity as revealed by the formation of a clear zone on chitin containing media, indicating that the gene could be expressed in E. coli cells. Chitinase gene expression in B. licheniformis N1 was not detected by RT-PCR analysis. The protein was over-expressed in E. coli BL21 (DE3) as a glutathione S-transferase fusion protein. The protein could also be produced in B. subtilis 168 strain carrying the chitinase gene of N1 strain. The crude protein extract from E. coli BL21 carrying GST fusion protein or culture supernatant of B. subtilis carrying the chitinase gene exhibited enzyme activity by hydrolyzing chitin analogs, 4-methylumbelliferyl-$\beta$-D-N,N'-diacetylchitobioside and 4-methylumbelliferyl-$\beta$-D-N,N',N"-triacetylchitotrioside. These results indicated that even though the chitinase gene is not expressed in the N1 strain, the coding region is functional and encodes an active chitinase enzyme. Furthermore, B. subtilis 168 transformants expressing the chitinase gene exhibited antifungal activity against Fulvia fulva by suppressing spore germination. Our results suggest that the proper engineering of the expression of the indigenous chitinase gene, which will lead to its expression in the biocontrol strain B. licheniformis N1, may further enhance its biocontrol activity.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.268-275
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• 2008

In order to develop the multi-functional rhizobacteria that can exert positive effect on the growth of plants growing in the coastal sand dune located along East Coast of Korea, rhizospheral bacteria of 11 different plants from this area were isolated 1,330 rhizobacteria. Among these, 23 strains were able to produce auxin and had spectrum of antagonism toward various phytopathogenic microbes. To know the mechanism of this antifungal activity, these 23 strains were subjected to further analyses; 19 strains of these produced siderophore as determined by color reaction on CAS-blue plate, 4 strains produced antifungal cellulase as judged by color change on CMC-Congo red plate, 17 strains were able to utilized insoluble phosphate salts, also determined by clear zone formation on PVK medium. Identification of the strain was assigned to all 23 strains by l6s rDNA sequence analysed, and all were identified to be in the genus of Bacillus and Pseudomonas. One strain of these, denoted Pseudomonas fluorescens IB4-14, showed ACC deaminase activity which is known to be involved in the resistance of environmental stress such as salt and drought. Also, P. fluorescens IB4-l4 showed the germination stimulation and roots growth promoting activity on the in vivo assay of Lysimachia mauritiana Lam. (spoonleaf yellow loosestrife).

• Journal of Applied Biological Chemistry
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• v.51 no.6
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• pp.296-301
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• 2008

The extracts from Salvia officinalis were studied for antioxidative activities and inhibitory activities against angiotensin converting enzyme(ACE) and xanthine oxidase (XOase). Total phenolic compounds were found as 22.28, 26.3, 24.63, and 28.22 mg/g in the water, 60% ethanol, 60% methanol and 60% acetone extracts, respectively. The antioxidant activities of Salvia officinalis extracts were measured as $64.4{\pm}1.5%$ at $200\;{\mu}g/ml$ on EDA, inhibition rate on ABTS of $96.9{\pm}0.2%$, antioxidant protection factor of $2.30{\pm}0.16$ PF and TBARS was $0.6{\pm}0.05$ (${\times}100\;{\mu}M$) in the control and $0.28{\pm}0.02$ (${\times}100\;{\mu}M$) in 60% ethanol extracts. Inhibitory activities was the ACE of 75.50% and XOase 100% in 60% ethanol extracts. The 60% ethanol extracts from Salvia officinalis exhibited antimicrobial activities against Helicobacter pylori such as 13 mm of clear zone and inhibition rate of 63.4% with $200\;{\mu}g/ml$ of phenolics content. Rosemarinic acid was the most abundant phenolic compounds as analyzed by HPLC. The results suggest that the 60% ethanol extracts from Salvia officinalis L. will be useful as natural antioxidants and functional foods.

• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.39-43
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• 2014

The antimicrobial activity of Orixa japonica Thunb. leaf extract towards 13 microorganism strains was evaluated. Both methanol (MEex) and 70% ethanol extracts showed antimicrobial activity towards Streptococcus mutans, Bacillus cereus, Staphylococcus aureus, and Pseudomonas aeruginosa. MEex showed a higher antimicrobial activity than the 70% ethanol extract. In addition, the dichloromethane fraction (DCMfr) of the MEex also had an antimicrobial effect against the microorganisms examined. The minimum inhibitory concentrations (MICs) towards S. mutans, B. cereus, S. aureus, and P. aeruginosa were 49.22, 24.61, 49.22, and 49.22 mg/mL, respectively. In contrast, the MICs of the DCMfr tpwards S. mutans, B. cereus, S. aureus, and P. aeruginosa were 3.31, 0.21, 1.7, and 1.7 mg/mL, respectively. The MEex antimicrobial activity was not affected by a 3 h exposures to pH in the range of 3-11 or by temperatures were maintained between $80^{\circ}C-100^{\circ}C$ for 6 h. However, the MEex antimicrobial activity decreased at a heat treatment of $121^{\circ}C$ 1 h.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.1
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• pp.51-61
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• 2014

It is necessary to perform a dynamic analysis to numerically evaluate the effect of blasting on nearby facilities. The blast load time history, which cannot be directly measured, is most often determined from empirical equation. The load has to be adjusted to account for various factors influencing the load and the frequency, but there is not a clear guideline on how to adjust the load. In this study, a series of 2D dynamic numerical analyses that simulates a closely monitored test blasting is performed, from which the blast load that matches the measured vibrations are derived. In the analyses, it is assumed that the hole generated by the blasting is in the form of a circle, and the load was applied normally to the wall of the opening. Special attention was given in selecting the damping ratio for the ground, since it has important influence on the wave propagation and attenuation characteristics of the blast induce waves. The damping ratio was selected such that it matches favorably with the attenuation curve of the measurement. The analyses demonstrate that the empirical blast load widely used in practice highly overstimates the vibration since it does not account for the energy loss due to rock fragmentation. If the empirical load is used without proper adjustment, the numerical analysis may seriously overstimate the predicted vibration, and thus has to be reduced in the analysis.

• Journal of Applied Biological Chemistry
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• v.54 no.4
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• pp.265-269
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• 2011

Inhibitory effect of useful components from Cheongmoknosang mulberry leaves extracts against Helicobacter pylori were investigated to develope them to a health functional food. It was confirmed that H. pylori bacterial infection occurred after 6 weeks over in C57BL/6 mouse which was caused the infection, and the average number of pathogens was $8{\times}10^5$ CFU/mL. Effects of the prevention and cure against H. pylori were tested by the mouth administration with Cheongmoknosang mulberry leaves extracts include the active ingredient, and number of H. pylori colony in stomach of drug groups were decreased more than control group. The result of testing immuno-glogulin isotype from the separated serum from a mouse, IgG1, IgA produced more in administered group, and it is expected to inhibit the H. pylori infection because of increasing antibody production in the mixture. These results suggest that caffeic acid, rosemarinic acid and chlorogenic acid in Cheongmoknosang mulberry leaves extracts are very effective to prevent or cure against H. pylori infection. So the ratio of infection is increasing and it is regarded to be able to prevent and cure the disease like gastritis, gastric ulcer and gastric cancer which are caused by H. pylori.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.325-331
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• 2009

Three beneficial bacterial agents, Lactobacillus strain KLF01, Lactococcus strain KLC02 and Paenibacillus strain KPB3 were showed clear zone against plated Pectobacterium carotovorum subsp. carotovorum (Pcc) soft rot pathogen. In greenhouse test, bio-control efficacy was more significantly effective in the treatments by KLC02 and KPB3 as 64%, 50%, 56% and 66%, 57%, 58% according to date of evaluation, respectively. In case of KLF01 control effect was relatively lower than treatments of KLC02 and KPB3 but its efficacy was still significantly observed when compared to control (only water treatment). Furthermore, KLF01, KLC02 and KPB3 showed 55%, 60% and 62% bio-control efficacy, respectively in field test from early March to late July of 2009. Thus, we suggest that these strains can be useful as bio-control agents against soft rot caused by Pcc.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.4
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• pp.3-11
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• 2001

To know the seawater infiltration into tidal flat sediment in coastal area is very important, because it is significantly correlated with the infiltration and transportation of pollutants in soil, the supply of dissolved oxygen, nutrients and organic matter to benthic organisms for survival of benthic organisms and the seawater purification. So, we set up purpose to clarify the infiltration behavior of seawater by wave action in tidal flat, to clear the effects of slope of tidal flat and breaking wave height on seawater infiltration and to quantify the infiltration volume of seawater. For purpose, the seawater infiltration was studied with visualization method by using coloring tracer and transparent glass beads replaced as natural sediment in model tidal flat. Specific conclusions derived from this study are as follows. The semi-circular type infiltration of seawater by wave action into saturated sediment was a new infiltration behavior that was not considered in previous studies. The infiltration rate of seawater was increased with increasing of breaking wave height and slope of tidal flat. However, the effects of the slope was bigger than that of breaking wave height on seawater infiltration into tidal flat sediments. It was possible to calculate the infiltration volume of seawater by wave action in natural tidal flat sediment and in fields. Therefore, we can point out that wave action play an important role in the supply of dissolved oxygen, nutrients and organic matter to benthic organisms, transportation or diffusion of pollutants and seawater purification. So, we hope to be studied the supply of food to benthic organism, pollutant transport and seawater purification on the base of these results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.667-673
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• 2017

This study was carried out to verify the antimicrobial effect of Graviola leaves against pathogenic bacteria for the purpose of developing an antibacterial material. The extraction conditions of graviola leaves were $60^{\circ}C$, $80^{\circ}C$ and $98^{\circ}C$, and graviloa leaves werewater extracted at $60^{\circ}C$, $80^{\circ}C$ and $98^{\circ}C$.The extraction yields and extraction conditions were determined. The antimicrobial activity against S. epidermidis, S. aureus and E. coli TOP10 was evaluated by agar diffusion method. The extraction yields were 3.02%, 14.73% and 20.76% at $60^{\circ}C$, $80^{\circ}C$ and $98^{\circ}C$, respectively. The antimicrobial activity against S. epidermidis, S. aureus and E. coli TOP10 was found in S. epidermidis.In the samples extracted at $98^{\circ}C$, a clear zone of 13 mm was observed at 200 mg/mL and of 20 mm at 500 mg/mL. The MIC was 100 mg/mL. The higher the extraction temperature and concentration, the better was the growth inhibition effect. As a result, the natural antimicrobial activity contained in natural materials can solve the problem of resistance to antibiotics. It is considered that antimicrobial activity against S. epidermidis in skin is highly applicable to basic cosmetics and cosmetic materials.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.705-710
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• 2004

This study was conducted to investigate the difference of antimicrobial activity between $\varepsilon$-polylysine/grapefruit seed extract mixture and $\varepsilon$-polylysine/glyceride mixture against food-borne pathogens. The minimum inhibitory concentration (MIC) of the $\varepsilon$-polylysine/grapefruit seed extract mixture was 100 times lower than that of the $\varepsilon$-polylysine/glyceride mixture. In case of the $\varepsilon$-polylysine/glyceride mixture the MIC of Bacillus cereus (0.1 $\mu$L/mL) and Pseudomonas aeruginosa (0.1 $\mu$L/mL) were lower than that of Escherishia coli (15 $\mu$L/mL). When rices were cooked with the $\varepsilon$-polylysine/glyceride mixture the number of total microbial cell was decreased during storage at 2$0^{\circ}C$ as concentration of the $\varepsilon$-polylysine/glyceride mixture increased. The antimicrobial activity was the highest against Escherishia coli as the concentration of the $\varepsilon$-polylysine/glyceride mixture increased. Sensory terms such as taste, flavor and texture were not significantly different in cooked rices prepared with 0.5% $\varepsilon$-polylysine/glyceride mixture, but there was significantly different in cooked rices prepared with 1% (p＜0.05) in the overall acceptability, indicating that the cooked rice with 0.5% $\varepsilon$-polylysine/glyceride mixture was recommended.