• Food Science and Preservation
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• v.12 no.6
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• pp.637-642
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• 2005

The antibacterial effect of methanol and water extracts from edible mushrooms on the growth of pathogenic bacteria (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Echerichia coli O-157, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhi) were investigated. The Lyophyllum cinerascens and Pleurotus ostreatus2 methanol extracts treated with 5.0 mg/disc showed the highest antimicrobial activity against 7 kinds of pathogenic bacteria. And methanol extracts of edible mushrooms showed higher antimicrobial activity against gram positive and gram negative microorganisms than water extracts. The methanol extracts of mushrooms revealed high inhibitive activites in cytotoxicity on human cancer HepG2 and HT-29 cells. The growth of cancer HepG2 and HT 29 cells which treated with 1 mg/mL of Cordyceps militaris and Sarcodon aspratus methanol extracts were strongly inhibited to $67\%$ and $81\%$ respectively. And most of the methanol extracts exhibited the stronger effects against these cells, at the same concentration, comparing with water extracts. Particularly, the methanol and water extracts of Cordyceps militaris, Agaricus blazei, Lyophyllum ulmarium, Ganoderma lucidum and Sarcodon aspratus have the strongest antitumoral effects on HepG2 and HT-29 cells. From these results, it is considered that wild mushrooms have stronger antimicrobial and in vitro cytotoxic effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.148-157
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• 2005

This study was investigated to determine antimicrobial activity of the water and ethanol extracts of Korean wild green tea, semi-fermented tea, and fermented tea. Antimicrobial activity was examined against 8 kinds of several microorganisms. The minimum inhibitory concentration (MIC) of the water and ethanol extracts of green tea showed the most active antimicrobial activity against B. subtilis 0.2 mg/mL in Gram positive bacteria and P. fluorescens 0.3∼0.5 mg/mL in Gram negative bacteria. But the extracts did not show antimicrobial activity against lactic acid bacteria and yeast at the level of less than 1 mg/mL. Antimicrobial activity got lower as tea got more fermented. Antimicrobial activity of ethanol extracts from green tea, semifermented tea, and fermented tea was stronger than that of water extracts. Antimicrobial activity of the water and ethanol extracts of green tea, semi-fermented tea, and fermented tea was not destroyed at 50∼121$^{\circ}C$, and pH 3∼11, which proved to be very stable when given over heat, acid & alkali treatment. The ethanol extract of green tea, semi-fermented tea, and fermented tea was fractionated in the order of hexane, diethyl ether, ethyl acetate and water fraction. The highest antimicrobial activity was found in the water fraction, but not found in hexane fraction, while antimicrobial activity of fermented tea was not found in ether fraction.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.308-315
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• 2011

The purpose of this work was to examine the antimicrobial activity derived from the lactic acid bacterium, UK-3 isolated from the vaginas of women of childbearing age. Various physiological and biochemical properties of this strain were characterized. Both the BIOLOG system and phylogenetic analysis using 16S rRNA sequencing were utilized for identification, and the strain was designated as Lactobacillus plantarum UK-3, and registered in GenBank as [JK266589]. Growth rate, production of organic acids (e.g., lactic acid and acetic acid), and pH during growth were monitored. The maximum concentrations of lactic acid and acetic acid were approximately 684.11 mM and 174.26 mM, respectively, and pH changed from 7.0 to 3.7 after 72 h of incubation. High performance liquid chromatography was used to confirm lactic acid and acetic acid production. Significant antimicrobial activity of the concentrated supernatant was demonstrated against various Gram-positive (e.g., Staphylococcus aureus, Staphylococcus epidermidis, Methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Neisseria species., Listeria monocytogenes), Gram-negative bacteria (e.g., Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis), and yeast (e.g., Candida albicans) by the plate diffusion method. As a result, the concentrated L. plantarum UK-3 cultures had lower acidity and inhibited the growth of all microorganisms tested, whereas the growth of L. acidophilus was not affected.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.721-726
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• 2012

Lactic acid bacteria (LAB) are able to secrete antimicrobial peptides called bacteriocins, which inhibit other bacteria such as pathogenic microorganisms. Therefore, bacteriocin-producing starters can be used as natural biopreservatives for various foods. The objective of this study was to screen and characterize bacteriocin-producing LAB from Kimchi and to investigate their applicability as a starter in Kimchi fermentation. To screen bacteriocin-producing LAB, gram-positive and gram-negative bacteria were used as indicators. To measure the antimicrobial activities of isolates, agar well diffusion assay method was used. According to the results, bacteriocin produced by $Lb.$ $sakei$ B16 showed antimicrobial activity against $Listeria$ $monocytogenes$ ATCC 19115, $Escherichia$ $coli$ KCTC 1467, and$Lactobacillus$ $plantarum$ KTCT 3104. Furthermore, bacteriocin was very stable after treatment with high temperature and high and low pH, but its effects were inhibited by treatment with proteolytic enzymes such as trypsin, proteinase K, and ${\alpha}$-chymotrypsin, revealing their bacteriocin-like protein- based structure. These results suggest that $Lb.$ $sakei$ B16 and its bacteriocin are good candidates as a functional probiotic and natural biopreservative, respectively, in fermented foods.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.255-262
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• 2010

Strain BCNU 2001 was isolated from soil samples collected from Tea-baek Mountain area. The biochemical characteristics and 16S ribosomal RNA gene sequences of the isolate revealed that the strain belonged to the Pseudomonas aeruginosa. The supernatants had an antimicrobial effect on various kind of bacteria and fungi. Especially BCNU 2001 was able to greatly inhibit the growth of Micrococcus luteus, Proteus mirabilis, Proteus vulgaris, and Aspergillus niger, and its inhibition zone was measured as 18.5 mm against Micrococcus luteus, 19.0mm against Proteus mirabilis, 17.0mm against Proteus vulgaris, and 13.5 mm against Aspergillus niger, respectively. Hexane and dichloromethane extracts of BCNU 2001 exhibited significant activity against bacteria, and dichloromethane and ethylacetate extracts showed significant activity against fungi. Pseudomonas strain BCNU 2001 was also determined to have antimicrobial peptide against various microorganisms including Gram positive bacteria, Gram negative bacteria and fungi. The obtained results may provide preliminary support for the usefulness of Pseudomonas strain BCNU 2001.

• Journal of Life Science
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• v.29 no.2
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• pp.223-230
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• 2019

Ozone is a gaseous molecule able to kill microorganisms, such as yeast, fungi, bacteria, and protozoa. However, ozone gas is unstable and cannot be used easily. In order to utilize ozone properly and efficiently, plant oil can be employed. Ozone reacts with C-C double bonds of fatty acids, converting to ozonized oil. In this reaction, ozonide is produced within fatty acids and the resulting ozonized oil has various biological functions. In this study, we showed that ozonized oil has antimicrobial activity against fungi and bacteria. To test the antimicrobial activity of ozonized oil, we produced ozonized olive oil. Ozonized olive oil was applied to Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. Antimicrobial activity was assayed using the disk diffusion method following the National Committee for Clinical Laboratory Standards. Minimal inhibitory concentrations (MIC) were 0.25 mg for S. aureus, 0.5 mg for S. epidermidis, 3.0 mg for P. aeruginosa, and 1.0 mg for E. coli. Gram positive bacteria were more susceptible than Gram negative bacteria. We compared growth inhibition zones against S. aureus and MRSA, showing that the ozonized olive oil was more effective on MRSA than S. aureus. Furthermore, the ozonized olive oil killed C. albicans within an hour. These data suggested that ozonized olive oil could be an alternative drug for MRSA infection and could be utilized as a potent antimicrobial and antifungal substance.

• Korean journal of applied entomology
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• v.19 no.3 s.44
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• pp.163-168
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• 1980

The antibiotic bacterium JS7901, one of the eighty three antibiotic microorganisms which have been is elated in the surburbs of CheongJu-city, showed the most effective antimicrobial activities against test organisms, both bacteria and fungi. Among the different culture media Soytone Sugar medium was the most effective for growth and activity of the JS7901 antibiotic bacterium a against both Escherichia coli and Staphyllococcus aureus by the cylinder plate method. The higher the sugar content, was, the greater the antibiotic amount of substances of JS7901 were produced in the soytone sugar media. The antibiotic bacterium, JS7901 appeared to have a broad activity spectrum showing inhibition in Vitro against gram positive and negative bacteria and plant disease fungi. In general, the active substances were not transferred into organic solvents. Only a small portion of the activity was transferred into ethyl ether and was also adsorbed to active carbon when the cultured broth was also adsorbed to active carbon when the cultured broth was at $pH\;2.0\~4.0$. On adjusting at pH 8.0, the activity disappeared. The crude active substances could be obtained by means of vacuum drying method and still shelved strong activity. The dried active rake was solved by solvents and crystallized into various shapes. The active substances were developed on the silica gel plate in the solvent system of n-butanol-acetic acid-water(3 : 1 : 1) and gave 5 pinkish colored spots when sprayed with $0.2\%$ ninhydrine in ethanol. The upper 5th spot, which was the result of using disc plate method with Escherichia coli was the strongest of these spots.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.4
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• pp.420-429
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• 2000

Oral & maxillofacial infections are most commonly odontogenic in origin. Although such infections are usually self-limiting, they may occasionally spread deeply into fascial spaces or planes far from the initial site of involvement. If early diagnosis and appropriate therapy is delayed, complications such as mediastinal extension, retropharyngeal spread and airway obstruction could happen to the patients. For the study of the microbiology, we have retrospectively analysed the oral & maxillofacial infected patients in the Dept. of Oral & Maxillofacial Surgery. In-Ha University Hospital from 1997 September to 2000 April. The results were as follows 1. The male patients were more common than female, with male 61.9% and female 38.1%. 2. Dental originated infections were most common cause with the incidence of 62%. 3. Most common fascial space involved was buccal space 42cases(37.2%) followed by submandibular space 13cases(11.5%), infraorbital space 13cases(11.5%), masseteric space 11cases(9.7%), periapical abscess 11cases(9.7%). 4. The causative organisms isolated from the pus culture were Gram Positive Bacterial species, which were 46cases(31.9%) of Streptococcus viridans, 16cases(8.6%) of ${\alpha}$ and ${\beta}-hemolytic$ streptococcus, 4cases(3.1%) of Strep.-group D non enterococci, 7cases(5.1%) of Staphylococcus Coa. neg., 5cases(3.9%) of Staphylococcus aureus, 3cases(2.3%) of Enterococcus faecalis, 1case(0.8%) of Bacillus species, 1case(0.8%) of Peptostreptococcus, 1case(0.8%) of Clostridium and Gram negative bacterial species, which were 4cases(3.1%) of Acinetobacter baumannii, 2cases(1.6%) of Pseudomonas aeruginosa, 2cases(1.6%) of Burkholderia cepacia, 1case(0.8%) of Neisseria species, 1case(0.8%) of Klebsiella pneumoniae, 1case(0.8%) of Klebsiella oxytoca, 1case(0.8%) of Escherichia coli. 5. In drug sensitivity test, high resistant tendency was found in Penicillin system(Penicillin G 83.3%, Ampicillin 60%) and Aminoglycosides (Gentamycin 50%, Tobramycin 45.5%), but tertiary Cephalosporin system(Cefoperazone 9.1%, Ceftazidime 18.2%), and glycopeptides system (Teicoplanin 0%, Vancomycin 0%) showed lower resistancy.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.69-74
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• 2016

The main constituent of tea catechins, EGCG [(-)-Epigallocatechin-3-gallate], could inhibit the growth of various microorganisms and differently affect gram-positive and gram-negative bacteria. Antimicrobial activity of EGCG, a compound from green tea (Camellia sinensis) extract, against Cronobacter spp. and Salmonella spp. was studied to evaluate the possibility of using EGCG as a natural food additive in various dairy products. In pure TSB culture, the growth of Cronobacter spp. was suppressed below the detection limit (1 log CFU/mL) depending on EGCG concentration ($600{\sim}800{\mu}g/mL$), after 5~16 days at $4^{\circ}C$. Similarly, the growth of Salmonella spp. was suppressed below the detection limit (1 log CFU/mL) depending on EGCG concentration ($400{\sim}800{\mu}g/mL$), after 5~16 days at $4^{\circ}C$. Therefore, these results suggest that EGCG could be used as an effective additive to inhibit the growth of Cronobacter spp. and Salmonella spp. in various dairy products, such as yoghurt, cheese, dried infant powder, and so on.

• Food Science and Preservation
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• v.10 no.4
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• pp.569-573
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• 2003

To determine the antimicrobial activity of methanol extracts form 'Formosa' plum against 4 kinds of pathogenic bacteria, the fermosa were got at different growth stages and were extracted using methanol, respectively. The Formosa methanol extracts treated with 5.0 mg/disc showed the highest antimicrobial activity against 4 kinds of pathogenic bacteria and those of Formosa 1-4(immature fruit), which thin out 10∼25 days before foal harvest, showed higher antimicrobial activity against gram positive and gram negative microorganisms than Formosa 5-6(mature fruit). Especially, the methanol extracts of Formosa 1 and 2 were exhibited the strongest growth inhibiting activities to these bacteria. The minimal inhibitory concentrations(MIC) of immature Fomosa methanol extracts was 320 $\mu\textrm{g}$/mL against Escherichia coli 0157:H7 and 160 $\mu\textrm{g}$/mL against Staphylococcus aureus respectively. The MIC of immature Formosa methanol extracts to Salmonella typhimurium and Listeria monocytogenes were 640 $\mu\textrm{g}$/mL. These results suggest that methanol extracs of immature formosa can be used as an effective natural antimicrobial agent in food.