• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.274-282
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• 2002

The ethanol extract and n-hexane fraction from Hypericum ascyron L. showed strong growth inhibition at 25 ppm on 5 strains of Listeria monocytogenes for 72 hr at $32^{\circ}C$. The purified substance, H2-5-2 fraction, was isolated by silica gel column and preparative thin layer chromatography from n-hexane fraction of Hypericum ascyron L. The H2-5-2 fraction showed a strong bacteriostatic activity on 5 strains of L. monocytogenes at 10 ppm in tryptic soy broth, and the viable cell was reduced 1 log cycle compared to initial cell number. The n-hexane fraction of Hypericum ascyron L. showed strong growth inhibition at 25 ppm on Bacillus cereus and Staphylococcus aureus, and at 50 ppm on Vibrio parahaemolyticus for 72 hr. The purified antimicrobial substance, the H2-5-2 fraction, was assumed as high unsaturated sterol by $^1H-NMR$ and $^{13}C-NMR$. On application test using minced Alaska pollack and ground beef, the n-hexane fraction of Hypericum ascyron L. at the level of 250 ppm was applied at $32^{\circ}C$ and $5^{\circ}C$. At $32^{\circ}C$ storage condition, the antimicrobial substances did not reduced L. monocytogenes ATCC 19113, meanwhile at $5^{\circ}C$ storage condition, L. monocytogenes ATCC 19113 was reduced in viable number.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.6-9
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• 2014

This study was for the investigation of the stability of purified bee venom (PBV) during the treatment in the pH range from pH2 to pH9 for 24 hours, respectively. Changes of components and physiological functionalities in PBV were by evaluated silver staining, and melittin contents were measured by liquid chromatography. The antimicrobial activity against bacteria by minimum inhibitory concentration (MIC) and effect of the cell regeneration were measured by 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl tetrazolium bromide (MTT) assay using human dermal fibroblast (HDF) cell. The main proteins such as melittin and phospholipase $A_2$ showed no characteristic changes. The antimicrobial activity and effect of cell regeneration showed no difference from pH2 to pH9. From this study, we suggest that components and physiological functionalities of PBV against treated pH were kept stability at from pH2 to pH9.

• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.45-55
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• 2007

Plant extract has attracted considerable interest in oral disease therapy. The present study was performed to observe the antibacterial effect on cariogenic Streptococcus mutans GS5 and Streptococcus sobrinus 6715, and periodontopathic Actinobacillus actinomycetemcomitans Y4 of phytoncide from Chamaecyparis obtusa Sieb. et Zucc employing the measurement of optical density, viable cell counts, and antibiotic sensitivity. The results were as follows: 1. Minimum inhibitory concentration of the phytoncide for S. mutans, S. sobrinus, and A. actinomycetemcomitans was observed to be 0.5%, 1%, and 0.2%, respectively. 2. Minimum bactericidal concentration of the phytoncide for S. mutans, S. sobrinus, and A. actinomycetemcomitans was determined to be 0.5%, 2%, and 0.2%, respectively. 3. The bacteria exposed to the phytoncide become more sensitive to antibiotics. The phytoncide enhanced significantly antibacterial activity of ampicillin against S. mutans and S. sobrinus. It also increased significantly the activity of penicillin and amoxicillin against S. sobrinus. In contrast, the phytoncide augmented the activity of amoxicillin and cefotaxime against A. actinomycetemcomitans but the increase was not statistically significant. The overall results indicate that phytoncide from Chamaecyparis obtusa Sieb. et Zucc used for this study has a strong antibacterial activity against cariogenic and periodontopathic bacteria and that it also has permeabilizing effect on certain antibiotics against these bacteria. Therefore, the phytoncide may be used as a candidate for prevention and therapeutic agent against oral infectious disease including dental caries and periodontal disease.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.979-985
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• 2010

This study was performed to detect enterococci strain as an indicator of faecal contamination, to identify of 16S rDNA sequence and vancomycin resistance by MIC (Minimum Inhibitory Concentration) test from drinking spring-water samples in Seoul. The detection frequency of enterococci was 42 (19.8%) among 212 samples, and its concentration was ranged from 0 to 110 CFU/100 mL. These results were confirmed the possibility as an indicator microorganisms that similar to the frequency of E. coli detection (t test p-value 0.268, significant level 0.05). Isolated 56 enterococci samples were identified by 16S rDNA sequence data and their NCBI BLAST searching. They were identified to Enterococcus faecalis of 24 samples, E. faecium (10), E. casseliflavus (10), E. gallinarum (3), E. hirae (2), E. durans (2), E. sanguinicola (1). E. faecalis was dominant species that clinical case report of a domestic was similar. Vancomycin resistant enterococci (VRE) of 53 samples showed that vanB and vanC1/C2 type with 2 and 12 case, respectively. These results indicated that the drinking spring-water quarantined to fecal pollution for block out outbreak of gastrointestinal symptom with using such as disinfection process.

• Korean Journal Plant Pathology
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• v.1 no.2
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• pp.128-135
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• 1985

Responses to the 14 fungicides added in PSA of penicillium expansum isolated froms the four major apple growing areas in Korea were examined. Degrees of the fungal tolerance were various with little difference by area and with great difference by kind and concentration of fungicide. Fall isolates of the fungus grew at higher fungicide concentration than did the spring isolates. $ED_{50}$ and MIC to mycelial growth of genomyl, garbenda, polydong, polyoxin and thiophanate methyl were $0.1{\mu}g-41.7{\mu}g/ml\;and\;100{\mu}g-2,250{\mu}g/ml,$, respectively, indicating high fungicide effects on the fungus isolated from decayed apples in storages and infected apples in orchards with low fungal tolerance; of captafol, captan, iprodione and mancozeb were $2.6{\mu}g - 750{\mu}g/ml\;and\;638{\mu}g-40,500{\mu}g/ml$, respectively, indicating medium degree of both fungicidal effects and fungal tolerance; and of chlorothalonil, folpet, oxidong, propineb and triademefon were $27.8{\mu}g-8,354{\mu}g/ml\;and\;2,625{\mu}g-150,357{\mu}g/ml$, respectively, indicating low fungicide effects and high fungal tolerance. Fungicidal inhibitory effects on conidia formation exhibited a similar trend as on mycelial growth whereas those on conidia germination showed an opposite trend to the mycelial growth with the exception of polyoxin and triademefon.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.279-284
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• 1996

To develop a selective medium for the isolation and the detection of leuconostocs from the various samples including fermented vegetables, ten strains of leuconostocs and seven strains of lactobacilli were tested for their sensitivity to various antibiotics. The basal-medium containing 5 ${\mu}g/ml$ of novobiocin inhibited the growth of lactobacilli completely, but not that of leuconostocs. On the basis of this result, a new selective medium was developed and to be named NLS medium. This medium contains 1% Tryptone (Difco), 0.1% Yeast Extract (Difco), 2% sucrose, 0.1% Beef Extract (BBL), 0.5% sodium acetate, 0.2% ammonium sulfate, 0.01% magnesium sulfate, 0.2% dipotassium phosphate, 0.05% sorbic acid, 75 ppm sodium azide (Sigma), 0.1% (vol/vol) Tween 80, 30 ${\mu}g/ml$ of Vancomycin (Sigma), 5${\mu}g/ml$ of Novobiocin (Sigma), 0.5${\mu}g/ml$ of cysteine HCI, and 1.5% Agar (Difco). All of the eighty six isolates obtained from some foodstuffs were identified as members of the genus Leuconostoc. Comparative counts with the MRS, PES, LUSM, and NLS medium indicated that the recovery percent was lower than other selective media. Therefore, this result suggested that NLS medium was suitable for the isolation of leuconostocs, but not for counting or enumerating.

• Food Science and Preservation
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• v.14 no.2
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• pp.207-212
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• 2007

The antimicrobial activity of Curcuma aromatica Salab. was investigated. The Curcuma aromatica Salab. extract showed antimicrobial activity against six pathogens tested. These were Listeria monocytogenes ATCC 19115, Pseudomonas fluorescens ATCC 21541,Staphylococcus aureus ATCC 29273, Salmonella typhimurium ATCC 21541, vibrio parahaemolyticus ATCC 17802, and Aeromonas hydrophila KCTC 2358. Antimicrobial activity was alsonoted when the extract was tested against four isolates of Bacillus sp. purified from spoiled tofu. The growth of various pathogens was significantly inhibited (100 10,000-fold) upon growth in tryptic soy broth containing 0.05 0.2%(w/v) Curcuma aromatica Salab. extract(CE), after incubation for 12hr at $37^{\circ}C$. The growth of the four Bacillus isolates was also significantly inhibited in nutrient broth containing 0.05 0.2% CE after incubation for 24hr at $37^{\circ}C$. Although the antimicrobial activity of CE was decreased by heat treatment at temperatures above $80^{\circ}C$, the activity remained relatively high after heat treatment at $121^{\circ}C$ for 15min. The minimum inhibitory concentrations of CE were 0.1 0.3%(v/v culture) for the six pathogens, and 0.2 0.25% for the Bacillus isolates, respectively.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.420-432
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• 2021

This study was conducted to evaluate antioxidant, antibacterial, anti-inflammatory, and digestive enzyme activity in water extract (SAW) and 60% ethanol extract (SAE) from Stachys sieboldii. As the treatment concentration of each extract S. sieboldii extract increased, antibacterial and antioxidant activity increased. The total polyphenol and total flavonoid contents of SAW were 106.25 ± 0.94 mgGAE/g, 24.4 ± 0.24 mgQE/g and SAE were 124.61 ± 1.11 mgGAE/g, 45.2 ± 3.52 mgQE/g, respectively. The 400 ㎍/mL of SAW and SAE performed more than 53% protective effects against oxidative stress in HepG2 cell lines. All extracts were not showed cytotoxicity to RAW 264.7 cell line at 100 ㎍/mL. NO production was reduced to 44.3 ± 1.4% for SAW and 45.1 ± 1.0% for SAE at a concentration of 100 ㎍/mL. The production of inflammatory cytokines each TNF-α, IL-1β, and IL-6 was inhibited in a concentration-dependent. S. sieboldii extract did not showed Caco-2 cells cytotoxicity and inhibited NO production in concentration-dependent. As the concentration of the S. sieboldii extract increased of α-amylase and protease enzymes activity, which are digestive enzyme. As a result of the experiment, it is judged that it can be used as basic data for the development of health food using S. sieboldii.

• Research in Plant Disease
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• v.20 no.1
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• pp.25-30
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• 2014

Phytophthora infestans was isolated from potato leaves collected from main potato producing areas in Korea during 2009-2011. In 2009, 99 isolates tested were all A1 mating type. Two of 64 isolates in 2010 and two of 78 isolates in 2011 were A2 mating type and they were found only in Miryang area. Among 99 isolates examined in 2009, 13.1% was resistant to metalaxyl, 3.1% was intermediate resistant and 83.8% was sensitive. In 2010, 19.4% of 62 isolates was resistant, 4.8% was intermediate and 75.8% was sensitive. Metalaxyl resistant, intermediate and sensitive isolates collected in 2011 were 23.1%, 9.0% and 67.9%, respectively. Metalaxyl resistant isolates increased mainly in winter cropping areas and seed potato producing areas where fungicides were sprayed more often. Frequencies of isolates showing minimum inhibition concentration of dimethomorph at $1.0-5.0{\mu}g/ml$ were 17.2% in 2009, 19.0% in 2010 and 15.4% in 2011. However, there was no evidence for occurrence of resistant isolate to dimethomorph because no isolate was able to grow at $5.0{\mu}g/ml$.

• Korean journal of food and cookery science
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• v.16 no.1
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• pp.40-46
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• 2000

The sensitivity of various pathogenic bacteria(Listeria monocytogenes, Staphylococcus aureus, Aeromonas hydrophila, Escherichia coli O157:H7 and Salmonella typhimurium) to the pine needle and green tea extracts was tested. Water extract of pine needle(PNW), 70% ethanol extract of pine needle(PNE), water extract of green tea(GTW) and 70% ethanol extract of green tea(GTE) were prepared for the test of antibacterial activty. Tryptic soy broth(TSB) containing 0∼2%(w/v) of pine needle and green tea extracts were inoculated with 10$\^$5/∼10$\^$6/ cells/ml of each bacterium and incubated at 35$\^{C}$ for 24 hours. The standard plate count method was used to measure the inhibitory effect of the extracts. Minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC) were derived from the survival curves of pathogenic bacteria. Antibacterial activities of the pine needle and green tea extracts were compared with that of sodium benzoate, a preservative, by clear zone test. L. monocytogenes, S. aureus and A. hydrophila were completely inhibited at 0.4∼1.6% level while E. coli and S. typhimurium were very resistant to the pine needle extracts. Green tea extracts completely inhibited all strains tested at 0.2∼1.0% level and bactercidal to all strains except L. monocytogenes at 0.5∼2.0% level. Antibacterial activities of pine needle and green tea extracts were stronger than that of sodium benzoate. The order of antibacterial activities of pine needle and green tea extracts to the pathogenic bacteria was GTE > GTW > PNE > PNW. This result suggests that green tea extracts can be used as an effective natural antibacterial agent in food.