• KSBB Journal
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• v.10 no.5
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• pp.553-560
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• 1995

A lactic aci bacteria producing antibacterial substance was isolated from pig feces. This strain was identified as a genus Lactobacillus, through its morphological, cultural and physiological characteristics. Lactobacillus sp. KJ-5 isolated showed the strong inhibitory effect on the growth of Salmonella paratyphi. The production of antibacterial substance was growth associated form during the batch culture of Lactobacillus sp. KJ-5 and the maximum production was obtained at the culture temperature of $37^{\circ}C$ as well as optimum temperature of cell growth. The antibacterial activity of the filtrate of culture broth was decreased by adjusting the pH 6.2 and was not affected by catalase treatment. The antibacterial substance was partially purified by methanol and acetone extraction, whtch exhibited three spots in the thin-layer chromatography and one of them showed an antibacterial activity, This substance also showed the maximum absorption of UV at 270nm and an antibacterial activity was completely inactivated by the treatment of proteolytic enzymes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.707-712
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• 1995

Natural antimicrobial activities in leaf mustard Dolsan(Brassica juncea) were evaluated for food preservation. Antimicrobial activities and changes in volatile allylisothiocyanate(AIT) concentration were examined during incubation of leaf mustard homogenate for 72 hours at $30^{\circ}C$. The concentration of volatile AIT was highest at 2 hours of incubation. Antimicrobial activities, which were insignificant in raw homogenate without incubation, were occurred at 21 hours and were showed highest at 48~72 hours of incubation. Water-pretreated extract(WPE) showed the antimicrobial activity by 1.2~1.4 times higher than the water extract. Ethylacetate fraction of leaf mustard showed high antimicrobial activities. The WPE had strong antimicrobial activities against Salmonella typhimurium and Staphylococcus aureus. Heat treatment of the WPE for 30 min at $121^{\circ}C$ did not lose the antimicrobial activities.

• Journal of Life Science
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• v.7 no.3
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• pp.180-185
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• 1997

Methylelaiophylin generated superoxide radicals in Bacillus subtilis and showed antibacterial activity against a broad range of gram positive bacteria. The inhibition of DNA synthesis was more sensitive than one of RNA synthesis. A recombination-deficient mutant strain of B. subtilis was 2-fold more sensitive than a wild strain, and this sensitivity was reduced in the presence of an antioxidant, dithiothreitol. Methylelaiophylin generated superoxide radicals in B. subtilis lysates, and this suggests that the antibacterial activity of methylelaiophylin is related to the generation of active oxygen species in the cells.

• Korean Journal of Agricultural Science
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• v.24 no.1
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• pp.50-54
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• 1997

Analysis of components in elven(trade name, Holon killer sand) and its antibacterial activity were studied. Zinc was the highest composition by the element analysis in the elven, and heavy metals concentration was quite low on the basis of drinking water standard of this country. The antibacterial activity for 24hr culture was the most effective in Bacillus Subtilis ATCC 6633. In which, there was no growth in 24hr when 50% extract of elven was employed for the culture. And the next strong activity was shown in Stapylococus aaeruginosa ATCC 27853. But, Streptococcus mutans did not reveal any gowth inhibition by when elven extract of 10% was added in the culture broth.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.242-249
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• 2003

Antimicrobial activity of Caesalpina sappan L. extract (CS extract) against animal husbandry disease-related bacteria was studied. The CS extracts showed a significant antimicrobial activity against Gram(+) bacteria and this antimicrobial activity was most significant against Staphylococcus epidermidis. Minimum inhibitory concentrations (MIC) of CS was in the range of 0.8∼16 mg/ml and 0.8∼10 mg/ml, in the case of MeOH extracts and EtOH extracts, respectively. In addition, the antimicrobial activity of each solvent fraction was most significant with EtOAc layer. The antimicrobial activities of CS extracts against most microbial strains were stable by either heat treatment or acid treatment, whereas those against S. aureus and Sal. typhimurium were reduced by acid treatment. The inhibitory effect of CS extracts on microbial cell growth was further examined by the addition of 0, 100, 300, and 500 ppm of CS extracts into growth medium. The growth of gram(+) bacteria, S. aureus and S. epidermidis, was inhibited for 72 hours in all ranges of CS extracts added, but the growth of gram(-) bacteria was only inhibited when at least 100 ppm of CS extracts were added. Taken together, the antimicrobial activities of CS extracts were more effective against gram(+) bacteria compared to those against gram(-) bacteria.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.692-696
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• 2001

To develop natural food preservatives, ethanol and water extracts were prepared from the coriander (Coriandrum sativum L.) and antimicrobial activities were examined against 10 microorganisms which were food borne pathogens and/or food poisoning microorganisms and food-related bacteria and yeasts. Ethanol extract exhibited antimicrobial activities for the microorganisms tested, but not on lactic acid bacteria and yeast. Especially, minimum inhibitory concentrations (MIC) for Bacillus subtilis and Bacillus cereus were as low as 0.25mg/mL. antimicrobial activity of the ethanol extract was not destroyed by the heating at 121$^{\circ}C$ for 15min and not affected by pH. The ethanol extract of coriander exhibiting high antimicrobial activities was fractionated in the order of hexane, chloroform, ethylacetate and butanol fractions to test antimicrobial activity. The highest antimicrobial activity adjust bacteria tested was found in the ethylacetate fraction.

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.235-240
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• 2000

Various separation techniques of antimicrobial compounds from food materials have proven to be ineffective, involving liquid-liquid extraction and chromatography. We established efficient separation procedure for partially purifying antimicrobial compounds from Korean leek. Separation procedures consisted of ultrafiltration, liquid-liquid extraction, TLC and HPLC. Molecular weight of antimicrobial compounds were less than 5,000 dalton. Major compounds were propenyl methyl disulfide, S-methyl methylthiosulphonate and dimethyl disulfide.

• Journal of Food Hygiene and Safety
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• v.14 no.4
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• pp.422-427
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• 1999

Antimicrobial activity of Korean leek was effective on Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, E. coli O157:H7, Pseudomonas fluorescens, Pichia membranaefaciens. Extract from raw Korean leek and that from frozen one showed antimicrobial activity; in contrast, extract stored frozen condition or extract from blanched one lost antimicrobial activity. Filtration, centrifugation, and vacuum concentration did not affect antimicrobial activity of the leek, nor did the changes in storage pHs. Addition of ground leek to soy milk, soy curd, and broth for cold noodle resulted in the prolonged shelf life by significantly reducing the number of viable cells.

• KSBB Journal
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• v.19 no.4
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• pp.291-294
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• 2004

The aim of this study was to figure out the antibacterial pattern of leucocin A transformed yeast with culture. Dry cell weight, total secreted protein, and antibacterial activity were increased to 12 hour, after then they showed decrease while protease activity represented the opposite pattern. This implied the production of leucocin A was growth-related. Compared to the result of one hour culture broth, antibacterial activity was about 3.24 fold at 12 hour culture. Maximum growth inhibition rate was 70.57% compared to nontransformed yeast. As the increase of protease in the supernatant, the antibacterial activity was diminished. This study could permit the mass production of bacteriocin to use as antibiotics or food preservatives.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.354-361
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• 1997

The antifungal activities of 153 extracts from 51 species of Korean mushroom on six phytopathogenic fungi were investigated. The powder of fruit-body of each mushroom was extracted with petroleum ether, 80% ethanol and distilled water. The water extracts of four mushrooms including Amanita virosa showed antifungal activities on Alternaria alternata, Colletotrichum graminicola, Fusarium solani, Idriella bolleyie. The 80% ethanol extracts of seven mushrooms including Boletus auripes showed antibiotic activities against A. alternata, C. gramincola, Cylindrocarpon destructans, F. solani, F. oxysporum cucumerinum, and I. bolleyie. The petroleum ether extracts of six mushrooms including Amanita citrina showed antibiotic activities against A. alternata, C. destructans, and C. graminicola. The 102 extracts of 34 mushrooms including Agaricus arvensis didn't show antibiotic activities.