• Journal of Dairy Science and Biotechnology
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• v.36 no.3
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• pp.155-163
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• 2018

In this study, the antibacterial activity of Aronia melanocarpa (black chokeberry) ethanol extract against Bacillus cereus, Staphylococcus aureus, Cronobacter sakazakii, and Salmonella Enteritidis was investigated using the spot-on-lawn assay. The results showed that this extract exhibited antibacterial activities against Bacillus cereus (complete inhibition) and Staphylococcus aureus (partial inhibition), but did not inhibit the growth of Cronobacter sakazakii and Salmonella Enteritidis. This study shows that the Aronia melanocarpa (black chokeberry) ethanol extract was more effective against Gram-positive bacteria than Gram-negative bacteria. Hence, it is suggested that Aronia melanocarpa could be a useful food supplement, and could be utilized as a naturally derived additive for maintaining the safety of various dairy products. Furthermore, future research should be conducted to examine the possibility of using such products as functional ingredients for improving the anti-oxidative and anti-inflammatory activities of food products.

• Microbiology and Biotechnology Letters
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• v.46 no.3
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• pp.225-233
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• 2018

In this exploratory study, eight types of microalgae from different phyla (Chlamydomonas reinhardtii, Chlorella species, Haematococcus pluvialis, Porphyridium purpureum, Porphyridium cruentum, Isochrysis species, Isochrysis galbana, and Pavlova lutheri) were tested for their antibacterial activities against eight target pathogenic bacterial strains. The agar well diffusion method and broth micro dilution assay were conducted to estimate the antibacterial activity. Microalgae cell-free supernatants, exopolysaccharides (EPS), water, and organic solvent extracts were used for inhibition analysis. EPS extracted from P. lutheri showed activity against Bacillus subtilis and Pseudomonas aeruginosa. Inhibition zone diameters of 14-20 mm were recorded on agar plates, while the minimum inhibitory concentrations in the broth micro dilution assay were $0.39-25mg\;ml^{-1}$. During this study, haptophyte microalgae, Isochrysis species, and P. lutheri extracts showed the highest activity against most of the tested pathogenic bacterial strains, while most of the extracts were active against the important foodborne pathogen P. aeruginosa. This study showed promising results regarding important microalgae phyla, which will further aid research related to extracts and exploitation of bioactive metabolic compounds in the food and pharmaceutical industries.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.444-447
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• 2015

This study was carried out to determine the antibacterial activity of $SeO_2$ against pathogenic bacteria, methicillin-resistant Staphylococcus aureus (MRSA). Using the disc diffusion method, $SeO_2$ showed higher antibacterial activity against Gram-positive bacteria than Gram-negative bacteria used in this study. Coccus-form bacteria showed much susceptible to $SeO_2$, compared to bacillus-form bacteria. Compared to antibiotics-susceptible S. aureus, antibiotics used in this study showed lower antibacterial activity against MRSA. As $200-500{\mu}g/disc$ of $SeO_2$ was applied, diameters of clear zone for S. aureus and MRSA were 20-32.7 mm and 13.5-17.9 mm, respectively. For MRSA, minimal inhibitory concentration of $SeO_2$ was $40{\mu}g/ml$. When $SeO_2$ was added in culture broth, cell growth of MRSA was inhibited. These results will be applied to determine antibacterial mechanism of MRSA and other pathogenic microorganisms.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.111-113
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• 2008

In this study, for natural leather use, the phytoncide oil of antibacterial materials was encapsulated in several micro-diameter shell which slowly releases from the leather treated with antibacterial microcapsules. The microcapsule was synthesized by in-situ polymerization of urea and formaldehyde. The effects of surfactants on the average particle size and distributions, morphologies and antibiosis were investigated to design microcapsule.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1763-1772
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• 2017

This study aimed to isolate and characterize antibacterial metabolites from Pharbitis nil seeds and investigate their antibacterial activity against various plant pathogenic bacteria. The methanol extract of P. nil seeds showed the strongest activity against Xanthomonas arboricola pv. pruni (Xap) with a minimum inhibition concentration (MIC) value of $250{\mu}g/ml$. Among the three solvent layers obtained from the methanol extract of P. nil seeds, only the butanol layer displayed the activity with an MIC value of $125{\mu}g/ml$ against Xap. An antibacterial fraction was obtained from P. nil seeds by repeated column chromatography and identified as pharbitin, a crude resin glycoside, by instrumental analysis. The antibacterial activity of pharbitin was tested in vitro against 14 phytopathogenic bacteria, and it was found to inhibit Ralstonia solanacearum and four Xanthomonas species. The minimum inhibitory concentration values against the five bacteria were $125-500{\mu}g/ml$ for the n-butanol layer and $31.25-125{\mu}g/ml$ for pharbitin. In a detached peach leaf assay, it effectively suppressed the development of bacterial leaf spot, with a control value of 87.5% at $500{\mu}g/ml$. In addition, pharbitin strongly reduced the development of bacterial wilt on tomato seedlings by 97.4% at $250{\mu}g/ml$, 7 days after inoculation. These findings suggest that the crude extract of P. nil seeds can be used as an alternative biopesticide for the control of plant diseases caused by R. solanacearum and Xanthomonas spp. This is the first report on the antibacterial activity of pharbitin against phytopathogenic bacteria.

• ALGAE
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• v.29 no.1
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• pp.47-55
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• 2014

To develop effective and safe acne vulgaris therapies with a continuing demand for new solutions, we investigated unique efficacy of an antibacterial agent from marine brown alga Eisenia bicyclis in treating acne vulgaris. The methanolic extract of E. bicyclis exhibited potential antibacterial activity against acne-related bacteria. The ethyl acetate fraction showed the strongest antibacterial activity against the bacteria among solvent fractions. Six compounds (1-6), previously isolated from the ethyl acetate fraction of E. bicyclis, were evaluated for antibacterial activity against acne-related bacteria. Among them, compound 2 (fucofuroeckol-A [FF]) exhibited the highest antibacterial activity against acne-related bacteria with a minimum inhibitory concentration (MIC) ranging from 32 to $128{\mu}g\;mL^{-1}$. Furthermore, FF clearly reversed the high-level erythromycin and lincomycin resistance of Propionibacterium acnes. The MIC values of erythromycin against P. acnes were dramatically reduced from 2,048 to $1.0{\mu}g\;mL^{-1}$ in combination with MIC of FF ($64{\mu}g\;mL^{-1}$). The fractional inhibitory concentration indices of erythromycin and lincomycin were measured from 0.500 to 0.751 in combination with 32 or $64{\mu}g\;mL^{-1}$ of FF against all tested P. acnes strains, suggesting that FF-erythromycin and FF-lincomycin combinations exert a weak synergistic effect against P. acnes. The results of this study suggest that the compounds derived from E. bicyclis can be a potential source of natural antibacterial agents and a pharmaceutical component against acnerelated bacteria.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.4
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• pp.165-171
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• 2002

The study on the adsorption, the surface properties and the antibacterial effects of the metal-treated pitch based activated carbon fibers was carried out. From the adsorption studies on the series of metal-treated activated carbon fiber, the specific surface areas of the metal treated activated carbon fiber obtained from BET equation were in the range of 113.2~1574 $m^2$/g for the Ag-ACFs. And that of Cu treated ACF are distributed to 688.2-887.8 $\m^2$/g. And, the specific surface areas of the Ni-treated pitch based ACFs were in the range of 692.6~895.2 $\m^2$/g. From the ${\alpha}_s$- method, 0.06~1.1 cm^3/g of the micropore volumes were obtained from Ag-ACFs. And, 0.1~0.2 cm^3/ and 0.2~0.6 cm^3/g of the micropore volumes were obtained from Cu and Ni-ACFs, respectively. And, from the SEM morphology results, it was observed that the surface of activated carbon fiber are partially blocked and coated by metal after the treatment. Finally, from the antibacterial effects of metal-treated activated carbon fiber against E. coli, the areas of antibacterial effect become larger with the increase in mole ratio of metal treated. And, from the antibacterial effects using Shake flask method against E. coli, the percentage of the effects was 92.5~100 % and the antibacterial effect was increased with the increase in mole concentration of metal treated.

• Journal of dental hygiene science
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• v.11 no.5
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• pp.405-410
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• 2011

The aim of this study was to evaluate antibacterial effect of Cl coated titanium. To coat the Cl on the titanium, first, the titanium was modified by blasting treatment with hydroxyapatite and alumina powder. Anodization process was completed using electrolyte solution of 0.04 M ${\beta}$-glycerol phosphate disodium salt n-hydrate, 0.4 M calcium acetate n-hydrate and 1 M NaCl on the condition of 250 voltages for 3 min. Surface morphology and elements' observation were performed with scanning electron microscopy and energy dispersive spectroscopy and surface profiler was used to analyze the surface roughness. Antibacterial effect was evaluated by film adhesion method. The anodized titanium after blasting showed dimpled surface contained the Cl. Surface average roughness of these surfaces had significantly higher compared to polished titanium. Result of antibacterial test showed that anodized titanium after blasting had an enhanced antibacterial effect compared to the polished titanium. Therefore, these results suggested that titanium contained Cl by anodization after blasting had a rough surface as well as antibacterial effect.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1461-1468
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• 2014

This study was aimed to examine the antibacterial and antioxidative properties of seven edible plants from Thailand to develop alternative antibiotics as feed additives. The plants include Citrus aurantifolia Swingle (Lime) fruits and its leaves, Sesbania grandiflora L. (Agati sesbania) leaves, Piper sarmentosum Roxb (Wild betal) leaves, Curcuma domestica Valeton (Turmeric) roots, Morinda citrifolia L. (Beach mulberry) leaves, Cassia siamea britt (Siamea cassia) leaves, and Cocos nucifera L. (Coconut) peels. The plants were extracted by methanol, n-hexane, chloroform, ethyl acetate, butanol and water. Antibacterial activities with minimum inhibitory concentration (MIC) were determined by agar diffusion assay against Escherichia coli, Burkholderia sp., Haemopilus somnus, Haemopilus parasuis, and Clostridium perfringens that were considered pathogenic strains in livestock infection. Methanol extracts of C. aurantifolia Swingle fruits and leaves showed the broadest spectrum of antibacterial activities except for C. perfringens. Butanol extract of S. grandiflora L. leaves showed the strongest activity against Burkholderia sp. with MIC, $135{\mu}g/mL$. P. sarmentosum Roxb leaves showed antibacterial activities against E. coli, Burkholderia sp. and H. parasuis. Ethyl acetate and water extracts from C. domesitca Valeton roots showed MIC of $306{\mu}g/mL$ and $183{\mu}g/mL$, respectively against only C. perfringens. Antioxidative activity was determined by 2-diphenyl-2-picryl hydrazyl photometric assay. The methanol extracts of C. aurantifolia Swingle fruits and P. sarmentosum Roxb leaves showed the highest antioxidant activity among all the extracts with 3.46 mg/mL and 2.70 mg/mL effective concentration 50% ($EC_{50}$) values, respectively. Total contents of phenolics and flavonoids were measured from the plant extracts. Methanol extracts of S. grandiflora L. and chloroform extracts of C. domestica Valeton were found to have the highest amount of total phenolics, 41.7 and $47.8{\mu}g/mL$, respectively. Flavonoid content of methanol extracts in S. grandiflora L. T was $22.5{\mu}g/mL$ and the highest among plant extracts tested. These results indicated that C. aurantifolia Swingle, S. grandiflora L., P. sarmentosum Roxb, and C. domestica Valeton have antibacterial and antioxidant activities and can be used as alternative antibiotics or potential feed additives for the control of animal pathogenic bacteria.

• Journal of Life Science
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• v.29 no.7
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• pp.785-791
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• 2019

In this study, we investigated the biological antioxidant and antibacterial activity of Chamaecyparis obtusa (C. obtuse) extracts by measuring DPPH radical scavenging and ABTS radical scavenging, and SOD-like activities. The DPPH and ABTS radical scavenging activities were increased in a dose-dependent manner, with maximum activities of 78% and 62% at an extract concentration of $50{\mu}l/ml$. The C. obtusa extracts also showed high SOD-like activity, with a maximum activity of 92.85% at a concentration of $50{\mu}l/ml$. The antibacterial activities of C. obtusa extracts were measured against six types of bacteria known to cause food poisoning and disease. Antibacterial activity was investigated against three gram-positive and three gram-negative bacteria using the paper disc agar diffusion method. The C. obtusa extracts showed antibacterial activities against B. cereus, E. coli, L. monocytogenes, S. aureus, S. typhi and V. parahaemolyticus, among which the activity against B. cereus was greatest. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of C. obtusa extracts were $30-40{\mu}l/ml$ for the 6 strains that showed an antimicrobial response by the paper disc agar diffusion method. These results suggest that C. obtusa extracts could serve as potential antibacterial agents to inhibit the growth of pathogens responsible for food poisoning and disease.