• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.92-98
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• 2001

Allelopathic effects of the cork tree (Phellodendron amurense Rupr.) on several crops and soil miro-organisms were assessed using germination bioassay and antimicrobial assay, and allelochemicals were identified. In a germination bioassay, extract of cork tree inhibited at high concentration on germination of several crop seeds such as cabbage, lettuce, and cucumber. However, aqueous extracts inhibited powerfully growth of test organisms such as Streptococus aureus, S. aureus, S. typhimurium, and E. coli as bacteria, and Candida albicans as yeast, and Botrytis cineria and Alternata alternaria as fungi.. The cork tree extract showed strong antimicrobial activities against isolated soil fungi. The allelochemicals were separated using Silica gel, Sephadex LH-20 gel column chromatography and HPLC. The substances were analyzed by UV spectrometry and EI-mass spectrometry. The active allelochemicals were identified as isoquinoline alkaloids, berberine and palmatine.

• Particle and aerosol research
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• v.5 no.3
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• pp.111-122
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• 2009

This paper reviews about synthesis of nanoparticles by spark discharge and applications. A method of catalytic activation with Pd and Pt aerosol nanoparticles produced by spark discharge was introduced. After annealing, the catalytically activated substrate placed into a solution for electroless silver deposition. The silver was then formed only on the activated regions of the substrate. Silver line patterns having a width of $18{\mu}m$ and a height of $1{\mu}m$ were created with the ability to be effectively reproduced. Antimicrobial nanoparticles such as silver were used for removal of bioaerosols. Silver nanoparticles deposited air filters such as ACF filters were evaluated by antimicrobial test.

• Journal of Life Science
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• v.10 no.2
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• pp.157-163
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• 2000

One hundred eight strains of Pseudomonas aeruginosa isolated from the patients (sputum, urine, burn skin, stool and blood) of Pusan National University hospital were tested for exonezyme production, antimicrobial susceptibility and serotyping. The results obtained were as follow: In exonezyme production test, 50 strains (46.30%) produced both protease and elastase. Thirty three strains (30.55%) did not produce any exoenzyme, 18 strains (16.67%) produced only protease and 7(6.48%) stains only produced elastase. As the result of antimicrobial susceptibility by the disc diffusion method, most strains were resistant to sulfamethoxazole (96.30%). But the resistant rate against gentamicin and ticarcillin were 47.23% and 46.30% respectively. The resistant rate to other antibiotics were less than 40%. All strains could be serologically typed. Most strains were identified as type Ⅲ: among them, 51 strains were belonged to serotype E. The correlation of serotype and exoenzyme production was not found.

• Textile Coloration and Finishing
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• v.12 no.5
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• pp.315-322
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• 2000

The purpose of this study was to investigate the antibacterial effects of natural colors extracted from yellow natural dyes(Tumeric, Amur Cork Tree and Onion Shell). The water and the methanol extracts of Tumeric and Amur Cork Tree significally decreased the growth of E. coli in vitro and the methanol extract of Tumeric exhibited the strongest inhibitory effect among the samples. Silk and nylon fabrics dyed with water and methanol extracts of the yellow natural dyes showed antimicrobial activities against E. coli and Staph aureus in the Bioassay Test. Nylon fabric dyed with methanol extracts of them showed strong antibacterial effect on E. coli compared with that of water extracts. However, slik fabrics dyed with the extracts could not reduce the growth of E. coli. Silk or nylon fabrics dyed with methanol or water extracts of yellow natural dyes showed antimicrobial activities against Staph aureus. The antimicrobial activity of the fabrics dyed with methanol extracts from Tumeric, Amur Cork Tree and Onion Shell was stronger than that of water extracts, especially, the fabrics dyed with Tumeric extract showed the highest antibacterial property among the dyed fabrics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.366-373
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• 2015

This study was conducted to clarify the antimicrobial effect, antioxidant and tyrosinase inhibitory activities of the biological composition having the Phytolacca americana, and to enhance the natural materials utilization of foods and cosmetics. The antimicrobial activities of the different parts of P. americana were evaluated using the agar diffusion test. The antimicrobial activity of P. americana was relatively high in Malassezia furfur known as a skin fungi and Vibrio parahaemolyticus compared to Escherichia coli and Staphy-lococcus epidermidis. However, the antimicrobial activity in Vibrio parahaemolyticus did not show at all parts of P. americana. Both the DPPH radical scavenging activity and ABTS radical scavenging activity have been increased with the higher concentration of methanol extract. In particular, leaf extract of P. americana exhibited the highest activity both ABTS radical scavenging activity and DPPH radical scavenging activity. The nitrite scavenging activity was decreased when the pH was changed from pH 1.2 to pH 6.0. The highest nitrite scavenging activity was exhibited from the methanol extract of fruit, followed by root, stem, and leaf at pH 1.2. However, the nitrite scavenging activity at pH of 6.0 was not almost detected. All plant parts of P. americana showed tyrosinase inhibitory activity. The highest activity was found in the stem, and followed by root, leaf, and fruit in order. These tyrosinase inhibitory activity was progressively increased in a concentration-dependent manner. In this experiment on the methanol extracts of different organ from P. americana, we confirmed that the extract of P. americana showed potent tyrosinase inhibitory activity. Taken together, we conjectured that the P. americana had the potent biological activities, therefore this plant having various functional components could be a good material for development into source of natural food additives and cosmetics.

• Advances in Traditional Medicine
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• v.4 no.3
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• pp.197-209
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• 2004

The study was aimed at evaluating the antioxidant and antimicrobial activities of methanol extract of Caesalpinia bonducella leaves (MECB) (Family: Caesalpiniaceae). The effect of MECB on antioxidant activity, reducing power, free radical scavenging (DPPH radical, nitric oxide radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide radical scavenging), total phenolic content and antimicrobial activities were studied. The antioxidant activity of MECB increased in a dose dependent manner. About 50, 100, 250 and 500 g of MECB showed 53.4, 61.2, 69.1 and 76.2 % inhibition respectively on peroxidation of linoleic acid emulsion. Like antioxidant activity, the effect of MECB on reducing power increased in a dose dependent manner. The free radical scavenging activity of MECB was determined by DPPH radical scavenging method. The potency of this activity was increased with increased amount of extract. MECB was found to inhibit the nitric oxide radicals generated from sodium nitroprusside $(IC_{50}\;=\;102.8\;g/ml)$ whereas the $IC_{50}$ value of curcumin was 20.4 g/ml. Moreover, the MECB was found to scavenge the superoxide generated by photoreduction of Riboflavin. MECB was also found to inhibit the hydroxyl radical generated by Fenton reaction, where the $IC_{50}$ value is 104.17 g/ml compared with catechin 5 g/ml, which indicates the antioxidant activity of MECB. The MECB capable of scavenging hydrogen peroxide in a concentration-dependent manner. The amounts of total phenolic compounds were also determined. Antimicrobial activities of MECB were carried out using disc diffusion methods with five Gram positive, four Gram negative and four fungal species. The results obtained in the present study indicate that MECB leaves are potential source of natural antioxidant and antimicrobial agents.

• Journal of Nutrition and Health
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• v.35 no.8
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• pp.880-885
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• 2002

This study was performed to determine the antimicrobial and anticarcinogenic activities of the Momordica charantia L. (MC) on several microorganisms and human cancer cell lines. In the paper disk test, its antimicrobial activity was increased in proportion to its concentration. Among the various solvent fractions of Momordica charantia L., the ethylether partition layer (MCMEE) showed the strongest antimicrobial activity. Also, the ethylacetate partition layer (MCMEA) and the butanol partition layer (MCMB) showed antimicrobial activity. We also determined the cytotoxicity and chemopreventive effect of Momordica charantia L. extract and fractions on human cancer cells. The experiment was conducted to determine the cytotoxicity of Momordica charantia L. partition layers on HepG2, HeLa and MCF-7 cells by MTT assay. Among the various partition layers of Momordica charantia L., MCMEE and MCMEA showed strong cytotoxic effects on all cancer cell lines. The chemopreventive effect of the quinone reductase induced activities of HepG2 cell, the hexane partition layer (MCMH) at a dose of 50 $\mu\textrm{g}$/mL was 3.62 times more effective compared with the control values of 1.0. Therefore, based on these studies, Momordica charantia L. may be developed into a potentially useful cancer chemopreventive agent.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.371-378
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• 2016

An aim of current study was to investigate the prevalence and the mechanism of quinolone-resistance in E. coli isolates obtained from chicken cecum in Korea. In addition, multilocus sequence typing (MLST) was also performed for the molecular characterization of E. coli isolates. In an antimicrobial susceptibility test by the disk diffusion method, the 63.5% (54/85) of E. coli isolates showed the resistance to quinolone group of antimicrobial agents. All of the 54 E. coli isolates showing resistant to quinolone group had sense mutations in gyrA gene and point mutations at the $57^{th}$, $80^{th}$, or $84^{th}$ residues in parC gene were detected in 90.7% of the isolates. Interestingly, E. coli ST was closely related to amino acid substitutions in parE gene. Our results indicated that the long-term use of antimicrobial agents in food-producing animals was strongly associated with a prevalence of antimicrobial resistance in commensal Enterobacteriaceae, suggesting the need for continuous surveillance and monitoring of antimicrobial resistant determinants in bacterial isolates from food animals.

• Food Science of Animal Resources
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• v.36 no.6
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• pp.787-790
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• 2016

Kefir is a unique fermented dairy product produced by a mixture of lactic acid bacteria, acetic acid bacteria, and yeast. Here, we compared the antimicrobial spectra of four types of kefirs (A, L, M, and S) fermented for 24, 36, 48, or 72 h against eight food-borne pathogens. Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, Escherichia coli, Salmonella Enteritidis, Pseudomonas aeruginosa, and Cronobacter sakazakii were used as test strains, and antibacterial activity was investigated by the spot on lawn method. The spectra, potencies, and onsets of activity varied according to the type of kefir and the fermentation time. The broadest and strongest antimicrobial spectrum was obtained after at least 36-48 h of fermentation for all kefirs, although the traditional fermentation method of kefir is for 18-24 h at $25^{\circ}C$. For kefir A, B. cereus, E. coli, S. Enteritidis, P. aeruginosa, and C. sakazakii were inhibited, while B. cereus, S. aureus, E. coli, S. Enteritidis, P. aeruginosa, and C. sakazakii were inhibited to different extents by kefirs L, M, and S. Remarkably, S. aureus, S. Enteritidis, and C. sakazakii were only inhibited by kefirs L, M, and S, and L. monocytogenes by kefir M after fermentation for specific times, suggesting that the antimicrobial activity is attributable not only to a low pH but also to antimicrobial substances secreted during the fermentation.

• KSBB Journal
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• v.15 no.6
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• pp.600-604
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• 2000

Low density polyethylene(LDPE) film was fabricated with the addition of synthetic ceramic which contained a natural antimicrobial agents. The antimicrobial agents used were isolated from culture broths of methylotropic actinomycetes strains MO-16 and MO-17, and Streptomyces sp. No. 31, which was newly isolated from soils as an antifungal agent. Four-day old culture broth of Streptomyces sp. No. 31 showed strong antifungal activity against Aspergilus niger, a test strain, and retained antimicrobial activity after heat treatment at $121^{\circ}C$ for 15 min. The ceramic LDPE film reduced the growth of total aerobic bacteria in packaged minced pork compared with commercial film. The film revealed a 40 to 50% growth inhibition of E. coli on a contained agar plate. In the storage testing of various packaged foods at room temperature for 30 days, the ceramic LDPE film showed excellent preservation compared with commercial film.