• Journal of Food Hygiene and Safety
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• v.24 no.3
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• pp.273-276
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• 2009

We investigated eight active natural antimicrobials for preservation of functional beverages that are usually degraded by yeasts rather than by bacteria due to a high sugar content and a low pH. Five strains of yeasts (S. cerevisiae, Z. bailii, P. membranaefaciens, C. albicans, and P Anomala) were tested with eight natural antimicrobial agents ($\varepsilon$-polylysine, yucca extract, vitamin $B_1$ derivative, scutellaria baicalensis extract, chitooligosaccharid, allyl isothiocyanate, sucrose-fatty acid ester, and oligosaccharide). The lowest minimal inhibitory concentrations (MIC) were 10 ppm for oligosaccharide and sucrose-fatty acid ester against S. cerevisiae and Z. bailii, 10 ppm for allyl isothiocynate against P. membranaefaciens and C. albican, and 10 ppm for allyl isothiocynate and oligosaccharide against P. anomala. No growth were observed for five kinds of yeasts in functional beverages containing sodium benzonate at concentration of 0.015% or higher. The resistance of S. cerevisiae, Z. bailii, and P. Anomala against natural antimicrobial agents was lower than those of P. membranaefaciens and C. albican. Allyl isothiocyanate, oligosaccharide, and sucrose-fatty acid ester showed the highest antimicrobial activities among the eight tested antimicrobials. These results can be applied to develop new natural antimicrobial agents to improve microbial quality of functional beverages.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.211-216
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• 2014

Bacillus cereus was isolated in 155 of 4,318 food samples from 2012 to 2013. Of the isolates, 140 isolates were performed antimicrobial disk test against garlic, cinnamon, ginger, and green tea extracted at two different temperature, $25^{\circ}C$ and $70^{\circ}C$. The isolates from Powdered Red Pepper showed frequently to 48.65%, and followed by Agriculture Products (31.08%) and Kimchi (25.61%). The isolation rate of Cooked Foods in the Restaurant supposed to causing food poison was 1.17%. Analysis of antimicrobial activity showed that $25^{\circ}C$ garlic extract, $25^{\circ}C$ green tea extract, and $70^{\circ}C$ green tea extract resisted against all 140 isolates and the others resisted against some isolates. Antimicrobial activity was depended on the temperature; garlic > green tea > cinnamon in $25^{\circ}C$ and green tea > garlic > cinnamon in $70^{\circ}C$. The correlation analysis of each extracts showed that geen tea extract was different significantly with garlic and cinnamon extracting in $25^{\circ}C$ and with only garlic extracting in $70^{\circ}C$ at p < 0.05.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.333-344
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• 2018

Selection of the optimal culture medium and evaluation of the antimicrobial activity against various phytopathogens were performed for four entomopathogenic fungal isolates with excellent insecticidal and antimicrobial activity against the two-spotted spider mite (Tetranychus urticae), green peach aphid (Myzus persicae), and gray mold (Botrytis cinerea). The optimal medium was selected by measuring the amount of blastospore production and the antifungal activity of the culture medium. On the basis of these experiments, GY medium was selected for Beauveria bassiana 2R-3-3-1 and Metarhizium anisopliae 4-2, SD3, and PDB medium for B. bassiana SD15. The antimicrobial activity test against other phytopathogens indicated that all four isolates showed high antifungal activities against Colletotrichum acutatum and Sclerotinia sclerotiorum. However, for Phytophthora capsici and C. fructicola, only M. anisopliae SD3 showed a high antifungal activity against P. capsici, and the other three isolates had little activity. Antibacterial activity against Clavibacter michiganensis subsp. michiganensis was high in two isolates of M. anisopliae but not in two isolates of B. bassiana. Thus, it was confirmed that entomopathogenic fungi effective for pest control could be effectively used as a control agent for various plant diseases.

• Food Science and Preservation
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• v.15 no.2
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• pp.288-292
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• 2008

This study examined the general components and biological activities of fruit from different cultivars of Prunus mume. The average moisture content of fruit ranged from 89.94-90.62%. The levels of crude protein, crude fat and crude fiber were not significantly different in the different cultivars. In an antimicrobial activity test, methanol extracts showed the highest activity and extracts from the Chunmae and Baekgaha cultivars had higherantimicrobial activity than other cultivars. The extract of fruit. However, there was no antimicrobial activity against the lactic acid- producing bacteria and yeasts, even at a concentration of 1.5 mg/mL or higher. Antimicrobial substances in methanol extracts of the fruit maintained their activity after heating at $100^{\circ}C$ for 30 minutes and were also unaffected by changes in pH. The antioxidant activities of extracts isolated with different solvents were: methanol > ethylacetate > water> ether> hexane. Antioxidant activity was not significantly different at different harvest times. The antioxidant index of the methanol extract was also the highest in electron donating activity.

• Journal of Life Science
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• v.20 no.10
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• pp.1505-1510
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• 2010

In this study, we investigated antimicrobial- and anticarcinogenic activities of Amphitrite albicostatu (AA) fractions. AA was extracted with methanol first and then further fractionated into four different types: hexane (AAMH)-, methanol (AAMM)-, buthanol (AAMB)- and aqueous (AAMA) partition layers. In the paper disk test, the antimicrobial activity of AA fractions increased in proportion to concentration. Among the various solvent fractions, only AAMB showed antimicrobial activity. We also determined the growth inhibition and quinone reductase (QR) induced effects of AA fractions on cancer cells. The growth inhibition effects of AA fractions on HepG2 and B16F10 cells were evaluated by MTT assay. AAMM showed the strongest growth inhibition effects on HepG2 and B16F10 cells. The quinine reductase (QR) induced effects of AAMM on HepG2 cells at 100 ug/ml concentration indicated it to be 2.04 times higher than the control values of 1.0. Although further studies are needed, the present work suggests that Amphitrite albicostatu (AA) could have a potential use as a food preservative and chemopreventive agent.

• Journal of dental hygiene science
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• v.13 no.1
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• pp.45-52
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• 2013

Antimicrobial activity of extract from some traditional oriental medicinal plants were evaluated for their antimicrobial activity against six oral pathogens, Streptococcus salivarius, Streptococcus oralis, Streptococcus mutans, Streptococcus sanguinis, Lactobacillus acidophilus and Lactobacillus casei, which are associated with caries disease. The antimicrobial activity was examined by determining the inhibition zone using the disc diffusion assay. In antibacterial activity test, extracts of Scutellaria baicalensis, Chrysanthemum indicum, Kochia scoparia, Hydnocarpus anthelmintica and Caesalpinia sappan showed inhibitory effects (40 mg/ml) against tested caries bacteria. Especially, the C. sappan extract showed the strongest activity on S. oralis (40 mm), L. casei (35 mm) and S. mutans (28 mm). Thus, this result suggests that C. sappan may be applicable to preventing dental caries.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.54-59
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• 1997

After extracting Caridina denticulata denticulata, the raw material of salt-fermented Toha, with the use of water, ether, acetone and methanol in order, we had the antimicrobial activity test for nine strains of bacteria which are harmful to the human body and food. It is as follows; solvent extract yield of the powder of vacuum freeze dried Caridina denticulata denticulata was 52% of water fraction, 7.4% of ether fraction, 1.0% of acetone fraction and 0.8% of methanol fraction. The result of solvent extract antimicrobial search of Caridina denticulata denticulata said that with the sample of 20$\mu\textrm{g}$/disk, ether fraction resulted in clear one of 8~12mm, acetone fraction 8~12mm, methanol fraction 7~9mm and water fraction didn't have antimicrobial effect. The minimal inhibitory concentration of solvent extract of Caridina denticulata denticulata per area was that ether fraction was 250~500$\mu\textrm{g}$/$m\ell$, acetone fraction 125~500$\mu\textrm{g}$/$m\ell$ and methanol fraction 250~500$\mu\textrm{g}$/$m\ell$. The minimal bactericidal concentration of solvent extract per area of Caridina denticulata denticulata showed that ether fraction was 2, 500~10, 000$\mu\textrm{g}$/$m\ell$, acetone fraction 1, 250~10, 000$\mu\textrm{g}$/$m\ell$ and methanol fraction 5, 000~10, 000$\mu\textrm{g}$/$m\ell$.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.464-470
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• 1994

The biological activities of Humulus japonicus were extracted by water and methanol. Methanol was better solvent than water in the extraction for antimicrobial activities against six different species of bacteria and two yeasts. The methanol extract was systematically fractionated with various organic solvents which have different polarities. From the result of antimicrobial activities against six species of bacteria and two species of yeasts, methanol extract was superior to water extract. The methanol extract of Humulus japonicus showed antimicrobial activity against the all species of microorganisms tested except Escherichia coli . The butanol fraction of methanol extract showed antimicrobial effect on the all species tested. The minimal inhibition concentration(MIC) of the butanol fraction on the growth of microorganisms was ranged between $0.1{\sim}0.4%$. The water extract of Humulus japonicus did not show inhibition of the activity of trypsin but methanol extract showed inhibitory activity. The chloroform fraction of methanol extract showed comparatively higher trypsin inhibitory activity than other fractions. The concentration of 50% inhibition$(IC_{50})$ by chloroform fraction was 1.0 mg/ml. Enzyme-inhibitor complex formation was above 90% of the while for 20 min. It was revealed that methanol extract of Humulus japonicus inhibited peroxide production of lard and soybean oil as substrate by antioxidative test. The chloroform fraction of methanol extract had the highest activity. When 0.2% of chloroform fraction was added, induction period of soybean oil and lard were extended 15, 9 days, respectively.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.449-455
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• 2012

The purpose of this study is to evaluate antimicrobial effects of organic acid and some natural occurring antimicrobials against Staphylococcus aureus isolated from various origins (vegetables, peanut, pea leaf, kim-bab, person, perilla leaf, and animal) and to calculate their MIC and MBC values. Five organic acids (acetic, lactic, citric, malic, and propionic acid), three essential oils (carvacrol, thymol, and eugenol), and two other natural antimicrobials (nisin and cinnamic acid) were evaluated for their antimicrobial effects against 113 strains of S. aureus using combination treatments. Propionic acid (7%), nisin (1%), thymol (1%), carvacrol (1%) showed antimicrobial activities against S. aureus strains in agar disc diffusion test. And, carvacrol, thymol, and nisin were found to be the most effective with the lowest MIC values of 0.0313%, 0.0625%, and 0.0625% against S.aureus, respectively. Propionic acid (0.2313%) and citric acid (0.6000%) were the most effective among organic acids tested. Therefore, these five antimicrobials were selected for next combination treatments. Combination of propionic acid and citric acid were showed the strongest inhibitory effectiveness against S. aureus among combination treatments. These results suggest that organic acid such as propionic and citric acid, and natural occurring antimicrobial such as nisin, carvacrol, and thymol might be possibly used as preservatives for inhibiting S. aureus in foods.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.3
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• pp.294-300
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• 2019

To investigate the inhibition effect on pathogenic microbes and the antimicrobial resistance of probiotics, a total of 140 probiotics were isolated from 35 kinds of Korean commercially available Kimchi. Of those, L. plantarum was identified from 53 strains (37.9%), E. faecium from 27 strains (19.3%), and L. rhamnosus from 7 strains (5.0%) using 16S rRNA gene sequencing. Sixty nine strains (49.3%) showed overall antimicrobial activity against pathogenic microbes, namely S. Typhi, S. Enteritidis, E. coli O157:H7, S. flexneri, NAG Vibrio, Listeria monocytogenesis, Y. enterocolitica, S. aureus, S. pyogenes, G. vaginalis, C. albicans, and P. acne. The proportions of L. plantarum, E. faecium, and L. rhamnosus strains to pathogenic microbes were 75.5%, 40.7%, and 28.6%, respectively. In addition, a resistance test with 18 antimicrobial agents using a disk diffusion assay revealed a resistance incidence of 98.6% for nalidixic acid, 83.6% for streptomycin, 75.7% for gentamicin 73.6% for vancomycin, 72.1% for norfloxacin, and 67.9% for ciprofloxacin. In conclusion, L. plantarum, L. sakei, and E. faecium strains with various antimicrobial activities and broad antibiotic resistance are useful for treating diarrhea in long-term inpatients and for the alternative use for treating Candida species female vaginitis.