• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.155-159
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• 2010

The antimicrobial activity of Sargassum fulvellum (SF) was investigated using the agar diffusion assay and MIC test. In addition, the stability of this activity under extreme heat and pH conditions was examined. The SF ethanol extract was shown to display strong antimicrobial activities against B. subtilis, C. perfringens, L. plantarum, S. aureus, L. monocytogenes, S. cerevisae and C. tropicalis in the agar diffusion assay at the concentration of 4 mg/mL. The MIC value of the SF ethanol extract against the tested microbes ranged from 0.05 to 0.0063%. In the heat and pH stability test, the antimicrobial activity of the SF ethanol extract was not altered when the temperature was maintained at $121^{\circ}C$ for 15 min, and it was also not affected in the pH range of 2-10. These results suggest that the SF ethanol extract is highly stable against drastic changes in temperature and pH.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.4
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• pp.361-373
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• 2015

This study was carried out to evaluate the antioxidant and antibacterial activities of Glycyrriza uralensis Fisher (Jecheon, Korea) extracts obtained by various extraction conditions (85% ethanol, heating temperatures and times), and to establish the optimal extraction condition of G. uralensis for the application as cosmetic ingredients. The extracts obtained under different conditions were concentrated and made in the powdered (sample-1) and were the crude extract solutions without concentration (sample-2). The antioxidant effects were determined by free radical scavenging activity ($FSC_{50}$), ROS scavenging activity ($OSC_{50}$), and cellular protective effects. Antibacterial activity was determined by minimum inhibitory concentration (MIC) on human skin flora. DPPH free radical scavenging activity of sample-1 ($100{\mu}g/mL$) was 10% higher in group extracted for 6 h than 12 h, but sample-2 didn't show any significant differences. The extraction yield extracted with same temperature for 12 h was 2.6 times higher than 6 h, but total flavonoid content was 1.1 times higher. These results indicated that total flavonoid content hardly increased with increasing extraction time. Free radical scavenging activity, ROS scavenging activity and cellular protective effects were not dependent on the yield of extraction, but total flavonoid content of extraction. Antibacterial activity on three skin flora (S. aureus, B. subtilis, P. acnes)of sample-1 in different extraction conditions were evaluated on same concentration, and the group extracted at 25 and $40^{\circ}C$ showed 16 times higher than methyl paraben ($2,500{\mu}g/mL$). In conclusion, 85% ethanol extracts of G. uralensis extracted at $40^{\circ}C$ for 6 h showed the highest antioxidant and antibacterial activity. These results indicate that the extraction condition is important to be optimized by comprehensive evaluation of extraction yield with various conditions, yield of active component, and activity test with concentrations, and activity of 100% extract, for manufacturing process of products.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.498-506
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• 2016

1, 2-Hexanediol galactoside (HD-gal) has been previously synthesized from 1, 2-hexanediol (HD), in which recombinant ${\beta}$-galactosidase (${\beta}$-gal) of Escherichia coli (E. coli) was used for transgalactosylation reaction. In this study, a method for HD-gal purification from the reaction mixture was particularly investigated. Using ${\beta}$-gal-containing E. coli, HD-gal was synthesized from 75 mM HD for 48 hr under 300 g/l lactose concentration. Then, HD-gal synthesis from HD was confirmed by TLC analysis, and the existence of E. coli ${\beta}$-gal during 48 hr-reaction was also confirmed by Western blotting, in which the conversion yield of HD to HD-gal reached about 94% during 48 hr. To establish an efficient method for HD-gal purification, we carried out the solvent extraction of the reaction mixture, followed by silica gel chromatography, particularly in order to remove the residual HD. Two water-immiscible solvents, such as methylene chloride and ethyl acetate, were investigated comparatively to find out appropriate solvent. Then, it was found that residual HD was almost removed when ethyl acetate extraction of water phase of reaction mixture was carried out four times. Subsequently, silica gel chromatography was carried out, and purified HD-gal could be finally obtained. The production yield for HD-gal from 75 mM HD was $8.9{\pm}0.6%$ (n=3) (mole basis) or $21.1{\pm}1.4%$ (n=3) (weight basis). For further study, using purified HD-gal, we will investigate the minimum inhibitory concentrations (MICs) of HD-gal against bacteria. In addition, cytotoxicity to human skin cells of HD-gal will be examined.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.170-175
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• 2009

The extract of Platycarya strobilacea is known to possess a wide range of pharmacological activities including anti-inflammatory, anti-fungal, and anti-cancer properties. We have reported that the ethyl acetate fraction of Platycarya strobilacea (PS-ET fraction) has high potential as an antioxidant agent (J. Soc. Cosmet. Scientists Korea 34(4) 275, 2008). In this study, antibacterial activity of the fraction and stability of the cream containing 0.2% PS-ET fraction were investigated for the application to cosmetics. Antibacterial activity of PS-ET fraction against various skin pathogenic bacteria (Propionibacterium acnes, Staphylococcus aureus, and Pityrosporum ovale) was measured by minimum inhibitory concentration (MIC). MIC values of PS-ET fraction on P. acnes, S. aureus, and P. ovale were 0.13%, 0.06% and 0.25%, respectively. The results showed that the antibacterial activity of the fraction was the highest in the S. aureus. For the stability evaluation, pH and viscosity of the cream containing 0.2% PS-ET fraction were measured. The results showed that pH changes of the cream containing PS-ET fraction was lower than the control cream without PS-ET fraction. And the PS-ET fraction could repress the decrease of viscosity of the cream against sunlight treatment. These results suggest that the fraction of Platycarya strobilacea has high potential as bactericide against the skin pathogenic bacteria and could be added to improve the stability of cosmetic products.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.537-548
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• 2016

The objective of this study was to evaluate the antimicrobial activities of 9 kinds of medicinal plants against crown gall in grapevine. The medicinal plants extracted with several solvent systems were screened for in vitro antibacterial activity by the disc diffusion method. The ethanol and ethyl acetate extracts from magic lily flowers, tachys roots, asian plantain flowers and seeds, sweet wormwood leaves, stems and flowers, immature bitter melon fruits, cockscomb flowers, and peach tree resin showed in vitro antimicrobial activities against Rhizobium vitis with growth inhibition zones ranging from 10 to 27 mm in diameter. The minimum inhibitory concentration values of extracts against R.vitis ranged from 10,000 in Asian plantain flower and 50,000 fold diluted extracts in sweet wormwood flowers, stems, leaves, cockscomb leaves and immature bitter melon fruits. The active fractions of ethyl acetate and ethanol extracts from the medicinal plants were partially separated through silica gel column chromatography and thin layer chromatography (TLC). The active fractions were separated at Rf 0.36, 0.69, 0.75, 0.84, and 0.94 in sweet wormwood extracts, Rf 0.96 and 0.99 in cockscomb flower extracts, Rf 0.92 and 0.97 in cockscomb leaf extracts, and Rf 0.85 in immature bitter melon fruit extracts in TLC analysis developed with hexane:ethyl acetate (20:80, v/v) and methanol:chloroform (20:80, v/v). Among extracts from plants with in vitro antimicrobial activities, sweet wormwood, cockscomb leaves, and immature bitter melon fruits showed in vivo antimicrobial activities with inhibition activity of 100, 67, and 83.3%, respectively, in 'Kyoho' grapevine inoculated with R. vitis compared with the untreated control. These findings indicate that extracts of medicinal plants could be used as sustainable candidates to control crown gall disease caused by R. vitis in grapevines.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.405-411
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• 2005

Chitosan, second largest biomass after cellulose on earth, has potential for use as functional food package due to its antibacterial activity. However, due to high melting temperature of chitosan, chitosan films have been made by casting method. Because gelatin has relatively low molting temperature depending upon amount of plasticizer added, it was added to chitosan to produce commercially feasible film. The objective of the current study was to determine optimum blend ratio and amount of chitosan/gelatin blend solutions against antibacterial activities for extruder resin. Gram-positive bacteria (Bacillus cereus ATCC 14579 and Listeria monocytogenes ATCC 15313) and -negative bacteria (Escherichia coli ATCC 25922 and Salmonella enteritidis IFO 3313) were used. Paper (8 mm) diffusion and optical density methods were used to evaluate effect of different blending ratio solutions on the inhibition of bacterial growth. Measured clear none size ranged from 8 mm to 18.07 mm in paper diffusion test. For B. cereus, E. coli, and S. enteritidis, addition of $50\;{\mu}L$ blend solution (chitosan/gelatin = 2/8: 0.3 mg) resulted in clear zone on paper disc. In L. monocytogenes, inhibition effect was observed with 0.6 mg chitosan (chitosan/gelatin=4/6). Minimum inhibitory concentration (MIC) values of B. cerues, L. monocytogenes, E. coli, and S. enteritidis with addition of chitosan were 0.1461, 0.2419, 0.0980, and 0.0490 mg/mL, respectively, These results indicate possibility of producing commercially feasible film with addition of optimum chitosan/gelatin amount.

• Journal of Applied Biological Chemistry
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• v.52 no.2
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• pp.77-83
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• 2009

This study was conducted to investigate the effect of the fermentation broth of fruits and vegetables and various kinds of lactobacillus containing in the broth on anti-microbial activity, anti-acidity, its organic acid concentrations and deorderization. In addition, the quality of eggs laid from the hens supplemented with the fermentation broth was determined. The fermentation broth contained over 8 kinds of lactobacillus and other microbes. Lactobacillus (L.) hilgardii, L. reuteri, L. nagelii, L. plantarum, and Zygosaccharomyces bisporus were survived especially in pH 2.0 among them. The concentrations of acetic acid and lactic acid in the broth were higher than minimum inhibitory concentration values (MIC) to Escherichia (E.) coli and Salmonella sp. Overall the broth contained sufficient organic acid to inhibit the growth of E. coli and Salmonella sp. In addition, L. nagelii and L. plantarum had the greatest anti-microbial activity against E. coli, Salmonella (S.) typhimurium, Staphylococcus aureus and S. gallinarium among lactobacillus in the broth. The broth had greater anti-microbial activity than individual lactobacillus. The fermentation broth had deodorization capacity of ammonia and hydrogen sulfate and the 50% of their concentrations were removed after 30 min treatment. Egg production rates, egg weight, and feed efficiency were increased in eggs laid from hens that supplemented with 0.1 % fermented broth compared to the control. The supplementation also increased the thickness and strength of egg shell to reduce broken eggs and decreased cholesterol levels in egg yolk. In conclusion, the fermentation broth of fruits and vegetables can be a natural alternative supplementation of feed in laying hens.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.240-245
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• 2012

Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium that causes serious infection, particularly in immunocompromised patients. Also, P. aeruginosa possessing carbapenem-resistant metallo-${\beta}$-lactamases (MBL) has been reported with increasing frequency in Korea. We therefore analyzed the level of multidrug-resistant clinical P. aeruginosa isolated from a secondary hospital in Korea in 2010. A total of 92 isolates of P. aeruginosa were collected from Sahmyook Medical Center in 2010. Susceptibility to antimicrobial agents was determined by analysis of the minimum inhibitory concentration test; the inhibitor-potentiated disk diffusion (IPD) test was performed for MBL detection. RAPD-PCR was used for genotyping to rapidly characterize P. aeruginosa strains isolated from clinical patients. The percentages of non-susceptible isolates were as follows: 40.2% to ceftazidime, 58.7% to meropenem, 56.5% to gentamicin, 46.7% to tobramycin, 62.0% to ciprofloxacin and 97.8% to chloramphenicol. The 29 multidrug-resistant strains were screened by the IPD test: of the 21 PCR-positive isolates, 19 were IPM-1 producers and 2 were VIM-2 producers. Among the 19 IMP-1-producing P. aeruginosa isolates, 16 isolates showed similar patterns, and three different banding patterns were observed. The proportion of IMP-1-producing multidrug-resistant P. aeruginosa from clinical isolates steadily increased in this secondary hospital in Korea in 2010. This study provides information about the antimicrobial-resistant patterns and genotype of multidrug-resistant P. aeruginosa isolated from clinical isolates in Korea, 2010.

• Journal of fish pathology
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• v.9 no.2
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• pp.185-193
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• 1996

Extensive acquirement of drug resistance to traditional antibacterial agents poses a serious problem to eel aquaculturists. To collect the basic information for new drug development in the future, we assessed the in vitro antibacterial efficacy of 14 new quinolones with 75 isolates of Edwardsiella tarda from local aquaculture tanks of Anguilla japonica. Of all tested quinolones under development or marketed for human use, DU-6859 was most potent with its $MIC_{50}$ value of $0.05{\mu}g$/ml in broth microdilution assay. The drugs whose $MIC_{50}$ values ranged from 0.2 to $0.78{\mu}g$/ml were T-3762, Bay-y3118, ciprofloxacin, norfloxacin, ofloxcin and tosufloxacin. The weakest group of drugs, with their $MIC_{50}$ being 1.56-$3.13{\mu}g$/ml, were difloxacin, sparfloxacin, fleroxacin, Q-35, amifloxacin, lomefloxacin and enoxacin. The number of resistant strains, when arbitrarily defined with their MICs of $\geq6.25{\mu}g$/ml, was : 3 to T-3762, 3 to Bay-y3118, 44 to difloxacin, 16 to sparfloxacin, 13 to ciprofloxacin, 19 to fleroxacin, 36 to Q-35). 31 to amifloxacin, 5 to norfloxacin, 13 to ofloxacin, 31 to lomefloxacin, 41 to enoxacin, 12 to tosufloxacin and 0% to DU-6859, respectively. This information can be taken into consideration for the future development of fisheries antibacterial quinolones.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.109-116
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• 2011

Purpose : Pneumococcus is one of the most important causes of invasive infection through the childhood period. In January 2008, the Clinical and Laboratory Standards Institute (CLSI) published revised penicillin breakpoints for Streptococcus pneumoniae and penicillin susceptibility rates of S. pneumoniae increased in Korea. This study was performed to determine the probability of oral amoxicillin for the empirical treatment achieving bactericidal exposure against pneumococcus using pharmacodynamics model. Methods : Twenty-three isolates of pneumococci were subjected to determine minimum inhibitory concentration (MIC) for ${\beta}$-lactams and macrolide. For the ${\beta}$-lactams, exposure of fT >MIC (time that free drug concentrations remain above the MIC) for 50% of the administration interval have determined the probability of target attainment (PTA), and regimens that had a PTA >90% were considered optimal. An analysis was performed by applying MIC of 23 isolates to a 5000-patient Monte Carlo simulation model. Results : Among 23 isolates from healthy children, 7 (30.4%) isolates were MIC ${\leq}$1.0 ${\mu}g$/mL and 19 (82.6%) were MIC ${\leq}$2 ${\mu}g$/mL for amoxicillin. Amoxicillin 40 mg/kg/day achieved PTA >90% at MIC ${\leq}$1.0 ${\mu}g$/mL but PTA decreased to 52% at MIC 2 ${\mu}g$/mL, whereas amoxicillin 90 mg/kg/day can predict 97% of PTA at MIC 2 ${\mu}g$/mL. Overall, oral amoxicillin 90 mg/ kg/day for the empirical treatment against pneumococcus can expect more successful response in Korean children. Conclusion : Considering the resistantce pattern of pneumococci in Korean children, we estimate that oral amoxicillin 90 mg/kg/day will provide a pharmacodynamic advantage for the empirical treatment against pneumococcus. And low dose amoxicillin or macrolide are expected to have higher chance of treatment failure than high dose oral amoxicillin.