• 한국지역사회생활과학회지
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• 제24권1호
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• pp.27-36
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• 2013

This study was performed to investigate the antimicrobial effect against food-borne pathogens of Sanguisorbae officinalis L. ethanol extract. The antimicrobial activity of the ethanol extract was determined using a paper disc-diffusion method and the diameter of the clear zone was measured. The diameters of the clear zone in the presence of 10 mg of the ethanol extract were the maximum against Staphylococcus aureus among the tested 4 gram-positive bacteria and Pseudomonas aeruginosa among the tested 7 gram-negative bacteria. Analysis of the minimum inhibition concentrations (MIC) showed that the ethanol extract exhibited a similar efficacy as sorbic acid, well-known chemical preservatives. The growth inhibitory effects of the ethanol extract in the concentrations of 250, 500, 1,000 and 2,000 mg/L on food-borne pathogens were determined against Staphylococcus aureus, Bacillus subtilis, Salmonella Typhimurium and Pseudomonas aeruginosa. The growth of the microorganisms was significantly (p<0.05) inhibited by the ethanol extract in the concentrations higher than 250 mg/L. Thus, the results of the present study demonstrate that the ethanol extract exhibits antimicrobial effects against food-borne pathogens, suggesting that Sanguisorbae officinalis L. could be used as natural antibacterial agent in food.

• International Journal of Oral Biology
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• 제36권1호
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• pp.7-11
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• 2011

Ursolic acid is a triterpenoid compound present in many plants. This study examined the antimicrobial activity of ursolic acid against mutans streptococci (MS) isolated from the Korean population. The antimicrobial activity was evaluated by the minimum inhibitory concentration (MIC) and time kill curves of MS. The cytotoxicity of ursolic acid against KB cells was tested using an MTT assay. The $MIC_{90}$ values of ursolic acid for Streptococcus mutans and Streptococcus sobrinus isolated from the Korean population were $2 {\mu}g$/ml and $4 {\mu}g$/ml, respectively. Ursolic acid had a bactericidal effect on S. mutans ATCC $25175^T$ and S. sobrinus ATCC $33478^T$ at > $2 \;{\times}\; MIC (4 {\mu}g$/ml) and $4 \;{\times}\; MIC (8 {\mu}g$/ml), respectively. Ursolic acid had no cytotoxic effect on KB cells at concentrations at which it exerted antimicrobial effects. The results suggest that ursolic acid can be used in the development of oral hygiene products for the prevention of dental caries.

• 한국식품과학회지
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• 제38권2호
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• pp.313-316
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• 2006

장내 상주균이며 probiotics로 활용되고 있는 Bifidobacterium에 대한 항생제 내성분포를 분석하였다. 분석된 93개의 Bifidobacterium이 chlolurnphenicol, rifampicin, erythromycin에 대해서는 감수성을 갖고 있었고, aminoglycoside계 항생제, nalidixic acid와 vancomycin에 내성을 갖는 것으로 나타났다. 그리고 vancomycin의 MIC가 $100\;{\mu}g/mL$ 이상인 균이 전체 균주 중 34%를 차지했다. Tetracycline, erythromycin, penicillin에 대한 내성은 매우 다양하게 나타났다. ${\beta}-lactam$계 항생제인 penicillin G와 cephalothin은 10년보다 더 내성이 높아졌음을 알 수 있었고, ampicillin, amoxicillin, tetracycline은 항생제 농도가 점차 증가하고 있는 것으로 보인다. 인체유래 분리균과 유산균식품 분리균의 항생제 내성은 대부분 비슷한 특성을 보였으나 유산균식품 분리 균주중 vancomycin의 MIC가 $100\;{\mu}g/mL$ 이상인 균주가 약 20%가 되는 것으로 나타났다. 따라서 새로운 probiotics를 개발하기 위해서는 이러한 항생제 내성 특성을 분석하고 항생제 내성 위해성에 대한 검증이 필요한 것으로 보인다.

• Journal of Microbiology and Biotechnology
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• 제29권8호
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• pp.1177-1183
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• 2019

Grapefruit seed extract (GSE) is a safe and effective preservative that is used widely in the food industry. However, there are few studies addressing the anti-biofilm effect of GSE. In this study, the anti-biofilm effect of GSE was investigated against biofilm-forming strains of Staphylococcus aureus and Escherichia coli. The GSE minimum inhibitory concentration (MIC) for S. aureus and E. coli were $25{\mu}g/ml$ and $250{\mu}g/ml$, respectively. To investigate biofilm inhibition and degradation effect, crystal violet assay and stainless steel were used. Biofilm formation rates of four strains (S. aureus 7, S. aureus 8, E. coli ATCC 25922, and E. coli O157:H4 FRIK 125) were 55.8%, 70.2%, 55.4%, and 20.6% at $1/2{\times}MIC$ of GSE, respectively. The degradation effect of GSE on biofilms attached to stainless steel coupons was observed (${\geq}1$ log CFU/coupon) after exposure to concentrations above the MIC for all strains and $1/2{\times}MIC$ for S. aureus 7. In addition, the specific mechanisms of this anti-biofilm effect were investigated by evaluating hydrophobicity, auto-aggregation, exopolysaccharide (EPS) production rate, and motility. Significant changes in EPS production rate and motility were observed in both S. aureus and E. coli in the presence of GSE, while changes in hydrophobicity were observed only in E. coli. No relationship was seen between auto-aggregation and biofilm formation. Therefore, our results suggest that GSE might be used as an anti-biofilm agent that is effective against S. aureus and E. coli.

• Asian-Australasian Journal of Animal Sciences
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• 제4권3호
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• pp.281-284
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• 1991

Combination effects of sulfamethoxazole (SMX) and trimethoprim (TMP) against nine gram positive bacterial strains and 43 gram negative bacterial strains which included 40 strains of animal intestinal bacteria were studied in vitro. Minimum inhibitory concentrations (MICs) of SMX and TMP alone and 20:1 (SMX : TMP) mixture (ST) were investigated by the method recommended by Ad Hoc Committee of the Japan Society of Chemotherapy for the Evaluation of Sensitivity Testing Methods for Sulfamethoxazole and Trimethoprim. MICs of ST were more potentiated than those of SMX alone in 8 of 9 gram positive strains and 40 of 43 gram negative strains. Especially, 38 strains of 40 intestinal bacteria showed significant susceptibility to ST as compared to SMX. These results suggest a strong synergistic activity of ST mixture against animal intestinal bacteria, The activity was considered to be comparable to those of other current antibiotics.

• Journal of Applied Biological Chemistry
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• 제48권4호
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• pp.167-169
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• 2005

Crude extract of bioconverted linoleic acid using Pseudomonas aeruginosa PR3 was evaluated for its antibacterial activity against food-borne pathogenic bacteria. Crude extract showed antibacterial activity against four Gram-positive bacteria, Staphylococcus aureus (ATCC 6538), S. aureus (KCTC 1916), Listeria monocytogenes (ATCC 19166), and Bacillus subtilis (ATCC 6633), and one Gramnegative bacterium, Pseudomonas aeruginosa (KCTC 2004), with minimum inhibitory concentrations ranging from 750 to $1,500\;{\mu}g{\cdot}ml^{-1}$. S. aureus and B. subtilis were selected for growth inhibition assays with bioconverted linoleic acid. Major antibacterial effects occurred at lag phase.

• Journal of Applied Biological Chemistry
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• 제49권4호
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• pp.131-134
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• 2006

The in vitro anti-fungal activity of hydroxylated fatty acids obtained from microbial conversion by Psuedomonas aeruginosa PR3 using ricinoleic acid(RA), eicosadienoic acid(EDA) and conjugated linoleic acid(CLA) as substrates, was investigated. Bioconverted hydroxylated fatty acids showed different anti-fungal activities potentials against the range of phytopathogenic fungi such as Botrytis cinerea, Rhizoctonia solani, Fusarium oxysporum, Sclerotonia sclerotiorum, Colletotricum capsici, Fusarium solani and Phytophthora capsici. RA and EDA showed up to 50% fungal mycelial inhibition at the concentration of $5{\mu}l\;ml^{-1}$. RA, EDA and CLA also exhibited anti-fungal activities with minimum inhibitory concentration(MIC), ranging from 500 to $1000{\mu}g\;ml^{-1}$. Screening was also carried out using varied concentrations of bioconverted RA and EDA for determining the anti-fungal effect on the spore germination of different fungi. Bioconverted RA and EDA showed a considerable degree of spore germination inhibition.

• Mycobiology
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• 제34권4호
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• pp.214-218
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• 2006

Four copper(II) complexes have been prepared using macrocyclic ligands. The macrocyclic ligands have been synthesized by the condensation reaction of diethyl phthalate with Schiff bases derived from o-phenylene diamine and Knoevenagel condensed ${\beta}-ketoanilides$ (obtained by the condensation of acetoacetanilide and substituted benzaldehydes). The ligands and copper complexes have been characterized on the basis of Microanalytical, Mass, UV-Vis., IR and CV spectral studies, as well as conductivity data. On the basis of spectral studies, a square-planar geometry for the copper complexes has been proposed. The in vitro antifungal activities of the compounds were tested against fungi such as Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans. All the synthesized copper complexes showed stronger antifungal activities than free ligands. The minimum inhibitory concentrations (MIC) of the copper complexes were found in the range of $8{\sim}28\;{\mu}g/ml$. These compounds represent a novel class of metal-based antifungal agents which provide opportunities for a large number of synthetic variations for modulation of the activities.

• Archives of Pharmacal Research
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• 제26권6호
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• pp.449-452
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• 2003

Systematic fractionation of Angelica gigas roots led to the isolation of linear furano(pyrano)coumarins such as bergapten (1), decursinol angelate (2), decursin (3), nodakenetin (4) and nodakenin (5). The antibacterial activities of those compounds against pathogenic bacteria were investigated. Among the compounds tested, decursinol angelate (2) and decursin (3) exhibited significant antibacterial activity against Bacillus subtilis with the minimum inhibitory concentrations (MICs) of 50 and $12.5{\;}{\mu}g/mL$, respectively.

• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.331-335
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• 2002

Aqueous extracts of garlic (Allium sativum) preparation were prepared after the samples were exposed to various heat treatments. A quantitative assessment of antimicrobial activities was carried out by determining the minimum inhibitory and microbicidal concentrations (MICs and MMCs) of the various extracts against some selected bacteria and fungi. The antimicrobial activity of garlic decreased as the heating temperature increased. This fact implies that alliinase may be the most critical rate-determinant to produce the activity when garlic is heated.