• Journal of Food Hygiene and Safety
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• v.27 no.2
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• pp.109-116
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• 2012

The study indicated that antimicrobial activity about gram positive and gram negative bacteria of ginger-oleoresin(GO) extract with the condition of ethanol and supercritical fluid extractions. As the concentration of extraction increases, the clear zone of GO ethanol extract also increased dependently. This led the antimicrobial activity of gram positive bacteria to take bigger place than gram negative bacteria especially in Listeria monocytogenes. There was a high antimicrobial activity in E-III treatment where the ratio of the ginger powder extract to ethanol extraction was 1:6. It was quite effective to treat the antimicrobial activity of GO ethanol extract under $80^{\circ}C$ and there was not big difference in the intervals which were the extraction time - 1 to 7 hours. The antimicrobial activity of supercritical fluid extract seemed to take the biggest place in Listeria monocytogenes. From the supercritical fluid extract, it was shown the strong ability of antimicrobial activity in the condition with 100 bar $35^{\circ}C$, 250 bar $35^{\circ}C$ and 250 bar $65^{\circ}C$. Furthermore, according to the case of solvent extract, there was not any significant difference in the antimicrobial activity with condition of extraction. However, there was significant antimicrobial activity in E-III treatment of 100 bar and 500 bar of extraction pressure, and $35^{\circ}C$ and $65^{\circ}C$ of extraction temperature.

• Food Science of Animal Resources
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• v.42 no.2
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• pp.252-265
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• 2022

Kocuria salsicia can survive in extreme environments and cause infections, including catheter-related bacteremia, in humans. Here, we investigated and evaluated the characteristics of nine K. salsicia strains (KS1-KS9) isolated from cheese brine from a farmstead cheese-manufacturing plant in Korea from June to December, 2020. Staphylococcus aureus American Type Culture Collection (ATCC) 29213 was used as a positive control in the growth curve analysis and biofilm-formation assays. All K. salsicia isolates showed growth at 15% salt concentration and temperatures of 15℃, 25℃, 30℃, 37℃, and 42℃. KS6 and KS8 showed growth at 5℃, suggesting that they are potential psychrotrophs. In the biofilm-formation analysis via crystal violet staining, KS6 exhibited the highest biofilm-forming ability at various temperatures and media [phosphate buffered saline, nutrient broth (NB), and NB containing 15% sodium chloride]. At 25℃ and 30℃, KS3, KS6, and KS8 showed higher biofilm-forming ability than S. aureus ATCC 29213. The antimicrobial resistance of the isolates was evaluated using the VITEK^® 2 system; most isolates were resistant to marbofloxacin and nitrofurantoin (both 9/9, 100%), followed by enrofloxacin (7/9, 77.8%). Five of the nine isolates (5/9, 55.6%) showed multidrug resistance. Our study reports the abilities of K. salsicia to grow in the presence of high salt concentrations and at relatively low temperatures, along with its multidrug resistance and tendency to form biofilms.

• The Korea Journal of Herbology
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• v.30 no.5
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• pp.51-58
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• 2015

Objectives : This paper aimed to verify the applicability of mixed extract ofAngelica gigasNakai,Cnidium officinaleMakino,Paeoniala ctifloraPall,Rechmannia glutinosaLibosch,Scutellaria baicalensisGeorgi, which were prescribed for improving inflammation in Donguibogam, as the materials for beauty food and functional medicinal herb cosmetics by manufacturing such mixed extract and evaluating the biological activity of the extract.Methods : The mixed medicinal herb water extract(MMW) and ethanol extract(MME) were freeze-dried to be used as the specimen. We performed electron donating ability, lipid acidification inhibitory activity, anti-inflammatory activity against skin flora, MTT assay, NO inhibitory activity and the protein expression inhibitory activity of iNOS and COX-2.Results : For anti-oxidation experimentation, the electron donating abilities of MMW and MME were above 60.0% and 90.0% at 500 μg/ml, respectively. In the inhibition rate of lipid peroxidation, MMW and MME showed 43.1% and 52.1% at 1,000 μg/ml, respectively. As a result of antimicrobial activity, both the MMW and MME showed significant clear zones forPropionibacterium acnesat 4 mg/disc, but did not indicated the clearzones forStaphylococcus aureus, Escherichia coliandStaphylococcus epidermidis. Anti-inflammatory activity by NO assay showed LPS-induced NO was significantly inhibited in a concentration-dependent manner. Also, the expression of iNOS and COX-2 proteins were significantly inhibited following treatment with MMW and MME of 50 μg/ml.Conclusions : Accordingly, it can be concluded that mixed medicinal herb extract has the potential to beused as a functional food and cosmetic material.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.3
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• pp.384-392
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• 2007

The primary objective of this study was to determine the effects of a water-distilled extract with 15 kinds of Korean medicinal herb on antioxidant activity, antimicrobial activity against Helicobacter pylori, and lipid metabolism. The water-distilled extract (WE) and fermenting water-distilled extract (FE) of medicinal herbs were utilized in order to make functional beverages. The EDA (electron donating activity), SOD-like ability, and RAE (relative antioxidant efficacy) of WE averaged 24.47, 50.35, and 1.57%, respectively, but the EDA, SOD-like ability, and RAE of FE was retardeded by 12.01, 35.72, and 1.55%, respectively. The antimicrobial activity against Helicobacter pylori of WE averaged 12.84 mm as a diametric clear zone, and was significantly (p<0.05) higher than those measured in the WE and control. Serum triglyceride contents, total serum cholesterol contents, and serum LDL-cholesterol contents of the WE group were significantly (p<0.05) lower than those of the control group. The liver total-cholesterol contents and liver triglycerides of WE group were significantly (p<0.05) lower than those of the control group. The plasma TBARS value of the WE group was significantly (p<0.05) lower than that of the control group. The sensory evaluation, taste, and smell of FE were more desirable than those of WE, but the color of WE was more desirable. According to the above results, the water distilled extracts (WE) of 15 kinds of medicinal herb are supposed to be effective with regard to antioxidant activity and lipid metabolism, but the antimicrobial activity against Helicobacter pylori was increased as the result of fermentation.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1481-1489
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• 2016

The emergence and dissemination of carbapenemase-producing Acinetobacter baumannii isolates have been reported worldwide, and A. baumannii isolates harboring bla_OXA-23 are often resistant to various antimicrobial agents. Antimicrobial resistance can be particularly strong for biofilm-forming A. baumannii isolates. We investigated the genetic basis for carbapenem resistance and biofilm-forming ability of multidrug-resistant (MDR) clinical isolates. Ninety-two MDR A. baumannii isolates were collected from one university hospital located in the Chungcheong area of Korea over a 5-year period. Multiplex PCR and DNA sequencing were performed to characterize carbapenemase and bap genes. Clonal characteristics were analyzed using REP-PCR. In addition, imaging and quantification of biofilms were performed using a crystal violet assay. All 92 MDR A. baumannii isolates involved in our study contained the bla_OXA-23 and bap genes. The average absorbance of biomass in Bap-producing strains was much greater than that in non-Bap-producing strains. In our study, only three REP-PCR types were found, and the isolates showing type A or type B were found more than 60 times among unique patients during the 5 years of surveillance. These results suggest that the isolates have persisted and colonized for 5 years, and biofilm formation ability has been responsible for their persistence and colonization.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.799-804
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• 2006

Antioxidative and antimicrobial activities were measured for the Pleurotus eryngii (P. eryngii) solvent extracts in order to discover new functional activities. In P. eryngii, the powder moisture was 9.0%, and the carbohydrate, crude protein, crude ash and crude fat contents were 63.06, 20.70, 5.20 and 2.0%, respectively. Among the detected minerals, potassium (K) had the highest levels and manganese (Mn) the lowest. The amount of polyphenol in EtEx (Ethanol Extract) was 387 mg% for the whole body, 158 mg% for the stipe, and 593 mg% for the pileus. Higher levels of polyphenol in the entire body were found in the BuEx (Butanol Extract) (594 mg%) and WaEx (Water extract) (404 mg%) of the P. eryngii powder. BuEx had the highest level in the pileus, and EtEx and BuEx were higher than the other extracts in the stipe. The electron donating ability (EDA) of EtEx of the P. eryngii powder was the highest, at 91.12%, for the whole body, while it was the lowest, at 62.90%, in the stipe. In addition, the EDA of WaEx was 90.39% for the whole body. These EDA values were similar to those for tocopherol (93.93%) and BHT (96.72%), supporting the potential of these extracts to act as antioxidants. A number of the extracts were certified to have antimicrobial activities for small number of microorganisms, especially for gram-negative microorganisms. In other words, BuEx and EAEx in the pileus and WaEx in the stipe were found to inhibit the growth of Pseudomonas aeruginosa (gram negative). Additionally, EtEx and WaEx in all parts were shown to act as antimicrobial agents for Escherichia coli of gram negative.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.5
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• pp.797-804
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• 2008

In this study, the antioxidative and antimicrobial activities of persimmon leaf tea and green tea were assessed. The total polyphenol contents of green tea (0.5875 mg/mL) were slightly higher than those of persimmon leaf tea (0.3938 mg/mL). The electron-donating abilities (EDA) of persimmon leaf tea and green tea toward $\alpha$, $\alpha$-diphenyl-$\beta$-picyryl hydrazyl (DPPH) radical were $65.7{\pm}3.7%$ and $68.4{\pm}0.3%$, respectively, as compared to $68.6{\pm}1.1%$ for L-ascorbic acid (1%). The SOD-like activity of persimmon leaf tea ($29.7{\pm}0.9%$) was higher than that of green tea ($28.1{\pm}1.0%$). The nitrite scavenging ability was pH-dependent, highest at pH 1.2, and lowest at pH 6.0, in and persimmon leaf tea was found to exhibit more effective nitrite scavenging ability than green tea. The inhibitory effects of persimmon leaf tea and green tea against angiotensin I converting enzyme were $56.7{\pm}1.9%$ and $67.1{\pm}1.7%$, respectively. Persimmon leaf tea evidenced profound antimicrobial activities against Listeria monocytogenes, Staphylococcus aureus, Escherichia coil, and Salmonella typhimurium. These results clearly established the antioxidative and antimicrobial potency of persimmon leaf tea.

• Journal of the Korean Society of Food Culture
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• v.22 no.4
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• pp.454-461
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• 2007

Antioxidative and antimicrobial activities were carried out on the Citrus Unshju peel solvent extracts in order to discover new functional activities. The amounts of polyphenol in 70% metanol extract (MtEx) was measured as 836.8 mg% in Citrus Unshju peel. The EDA (electron donating ability) of 0.01, 0.02 and 0.1% MtEx in Citrus Unshju peel were measured as levels of 81.3, 86.0 and 89.6%. The nitrite scavenging effects of Citrus peel were also determined as the levels of 34.4% (pH 1.2) and 19.5% (pH 7.0). The pH of react solution was more acidic, the nitrite scavenging effect was more increased. The order of antioxidatives was shown as TBHQ > BHT > TOC > ChEx > EaEx > EtEx > WaEx > Control in corn germ oil and TBHQ > ChEx > EaEx > BHT > EtEx > WaEx > TOC > Control in canola oil. A number of the extracts were certified to have antimicrobial activities for a small number of micro-organisms, similar gram negative and positive micro-organisms. According to the results above, it was summerized that Citrus Unshju peel had the higher total polyphenol, EDA, nitrite scavenging effects and antimicrobial activities. Also isolated extract from ChEx and EaEx had high antioxidative, these effects were very similar to that of ${alpha}$-tocopherol and BHT. It would be proposed that Citrus peel can become a new natural source for antioxidative agents in future food industry.

• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.502-507
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• 2016

This study was conducted to develop novel antimicrobial nano-composites, with the aim of fully utilizing antimicrobial properties of multi-walled carbon nanotubes (MWCNTs), nickel (Ni) and zinc oxide (ZnO). Ni coated-MWCNTs (Ni-CNT) were prepared and evaluated for their potential application as an antimicrobial material for inactivating bacteria. Field emission scanning electron microscopy (FE-SEM), and X-ray energy dispersive spectroscopy (EDS) were used to characterize the Ni coating and morphology of Ni-CNT. Staphylococcus aureus (S. aureus) and Escherichia coil (E. coil) were employed as the target bacterium on antimicrobial activities. Comparing with the nitric acid treated MWCNTs and Ni-CNT which have been previously reported to possess antimicrobial activity towards S. aureus and E. coil, Ni-CNT/ZnO exhibited a stronger antimicrobial ability. The nickel coating was confirmed to play an important role in the bactericidal action of Ni-CNTs/ZnO composites. Also, the addition of ZnO to the developed nanocomposite is suggested to improve the antimicrobial property.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.981-989
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• 2019

Coffee is a popular beverage worldwide, and the scale of consumption is growing rapidly. Many studies have shown that increased coffee consumption has various effects on human health, including beneficial effects on liver diseases, clinical type 2 diabetes, and Parkinson's disease. However, the influences of coffee or caffeine (a component of coffee) on the gut microbiota have not been examined in detail. Here, we tested whether caffeine could alter the antimicrobial activity of L. casei against E. coli. Interestingly, we found that treatment with 0.3 mg/mL caffeine increased the antimicrobial activity of L. casei against E. coli. This activity was not associated with the release of lactic acid but did appear to be related to a heat-labile factor present in the L. casei culture supernatant. Our analyses suggest that the putative antimicrobial factor found in the culture supernatant of L. casei treated with caffeine may be bacteriocin. Taken together, our results suggest that caffeine, which is an ingredient of coffee, increases the antimicrobial activity of L. casei against E. coli through the enhanced production of bacteriocin. These findings also suggest that coffee consumption affects the ability of beneficial bacteria to decrease pathogenic bacteria and/or prevent the progression of bacterial infection-associated diseases in the gut.