• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.437-443
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• 2013

The diversity of culturable non-actinobacterial (NA) bacteria associated with four species of South China Sea gorgonians was investigated using culture-dependent methods followed by analysis of the bacterial 16S rDNA sequence. A total of 76 bacterial isolates were recovered and identified, which belonged to 21 species of 7 genera, and Bacillus was the most diverse genus. Fifty-one percent of the 76 isolates displayed antibacterial activities, and most of them belonged to the Bacillus genus. From the culture broth of gorgonian-associated Bacillus methylotrophicus SCSGAB0092 isolated from gorgonian Melitodes squamata, 11 antimicrobial lipopeptides including seven surfactins and four iturins were obtained. These results imply that Bacillus strains associated with gorgonians play roles in coral defense mechanisms through producing antimicrobial substances. This study, for the first time, compares the diversity of culturable NA bacterial communities among four species of South China Sea gorgonians and investigates the secondary metabolites of gorgonian-associated B. methylotrophicus SCSGAB0092.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.1060-1077
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• 2021

Food additives are required to maintain the freshness and quality of foods, particularly meats. However, chemical additives may not be preferred by consumers, and natural materials with antimicrobial and antioxidant effects may be used as replacements for common chemical additives. Accordingly, in this study, we compared the antimicrobial and antioxidant activities of natural compounds extracted with ethanol and hot water, and emulsion sausage prepared with natural ethanol extracts was analyzed for pH, color, thiobarbituric acid reactive substances (TBARS), and Clostridium perfringens growth during storage. The antimicrobial activities of 49 natural extract candidates against Listeria monocytogenes, C. perfringens, Salmonella spp., and Escherichia coli were analyzed, and six natural materials with excellent antibacterial activities, i.e., Elaeagnus umbellata Thunb. f. nakaiana (Araki) H. Ohba, Punica granatum L., Ecklonia cava, Nelumbo nucifera Gaertner, and Schisandra chinensis (Turcz.) Baill., and Rubus coreanus Miq. were evaluated to determine their total polyphenol contents and DPPH radical scavenging activities. The total polyphenol contents of ethanol extracts were higher than those of hot water extracts, whereas DPPH radical scavenging activity was found to be higher in hot water extracts. The TBARS values of emulsion sausages were significantly increased as storage time increased, and the TBARS values of emulsion sausages prepared with natural extracts were lower than those of control sausages. Natural extract-treated emulsion sausages showed a 99% reduction in bacterial contents compared with untreated sausages on day 2, with greater than 99.9% reduction after day 3. Thus, these results demonstrated that natural extracts could have applications as natural preservatives in meat products.

• Microbiology and Biotechnology Letters
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• v.45 no.2
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• pp.133-142
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• 2017

Two hundred bacilli were isolated from rice straw, and 3 strains showing strong inhibitory activities against Bacillus cereus ATCC14579 were selected for further analyses. RSC15 was identified as B. licheniforms, and RSC26 and RSC42 were identified as B. amyloliquefaciens by molecular identification methods. The inhibitory activities were heat stable, and half of the activity was retained for 20 min at $100^{\circ}C$. SDS-PAGE analyses of the culture supernatant indicated that 2 different kinds of antibacterial substances were present with sizes below 3.5 kDa. Antibacterial substances produced by B. licheniformis RSC15 were partially purified by column chromatography, and the specific activity increased from 955.0 AU/mg to 6,400 AU/mg.

• Microbiology and Biotechnology Letters
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• v.36 no.3
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• pp.195-200
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• 2008

Saxifraga stolonifera (Saxifragaceae) is a perennial herbaceous plant growing in Korea, China, Japan and Russia. The aerial part has been used as herbal medicine for treatment of pneumonia, frostbite, inflammation and microbial infection. In this study, fresh juice and methanol extract were prepared from the aerial part of S. stolonifera, and their antimicrobial, antithrombin, and antioxidant activity were evaluated, respectively. The fresh juice showed weak antimicrobial activity against Proteus vulgaris, Escherichia coli O157:H7 and Candida albicans with ignorable DPPH scavenging activity. But, the methanol extract showed strong antioxidant activity ($IC_{50}$ of $37.5{\mu}g/mL$) with minor, broad-range antimicrobial activity. Antithrombin activities were not observed in fresh juice and extract, up to 1.5 mg/mL. Sequential organic solvent fractionation of methanol extract showed that $IC_{50}s$ of ethylacetate and the butanol fraction were 6.9 and $7.8{\mu}g/mL$, respectively, that is comparable with vitamin C or butylated hydroxytoluene. Analysis of component in extract and fractionates suggested that the antioxidants in fractions are diverse and the active substances have glycosylated phenolic structure. Our results suggest that the aerial part of S. stolonifera could be used as the natural source of potential antioxidant.

• Food Science and Preservation
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• v.23 no.2
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• pp.233-238
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• 2016

A effect of extraction methods, including stirrer extraction method (SE), ultrasonification extraction method (USE), reflux extraction method (RE), autoclave extraction (AE) and low temperature high pressure extraction (LE) method on the antioxidative and antimicrobial activities of ethanol extracts of Oenothera biennis was investigated. The extraction yield (46.33%), total polyphenol (463.05 mg GAE/g) and flavonoid (71.71 mg RHE/g) content of Oenothera biennis extract obtained by RE were higher than those from other extraction methods. The antimicrobial activity of Oenothera biennis extract was only observed against Bacillus cereus among other tested organisms (Bacillus cereus, Staphylococcus aureus, Escherichia coli and Salmonella Typhimurium). Oenothera biennis obtained by RE showed the best DPPH radical scavenging ability (74.40%), ABTS radical scavenging ability (65.29%), reducing power (1.370 ($OD_{700}$)) and ferrous ion chelating ability (90.14%) compared with other tested extraction methods tested. The RE method was the most efficient method for extracting crude antioxidant and antimicrobial substances from Oenothera biennis. These results suggested that Oenothera biennis obtained by RE could be used as a bioactive and functional material in the food industry.

• 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.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.367-372
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• 2015

This study was aimed at determining the antioxidant and antimicrobial effects of solvent extracts from Asparagus cochinchinensis. The Asparagus cochinchinensis was extracted with water, methanol, ethanol, n-hexane, dichloromethane, ethyl acetate, and ether. The antimicrobial activity of these extracts was determined by modified well diffusion methods against 4 species of respiratory disease bacteria (Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis, and Pseudomonas aeruginosa). In addition, the amount of total polyphenol and flavonoid content, and antioxidant activity was evaluated. Ethyl acetate extract of A. cochinchinensis exhibited higher antimicrobial activity against tested microorganisms than water, methanol, ethanol, n-hexane, dichloromethane, and ether extracts. For antioxidant activity, the ethyl acetate extract of A. cochinchinensis exhibited a notable effect on the scavenging of superoxide against DPPH ($IC_{50}=3.81mg/ml$). Finally, the total polyphenol and flavonoid contents were $14{\pm}0.7mg/g$, and $0.50{\pm}0.13mg/g$, respectively. These results can be regarded as basic research into A. cochinchinensis for the prevention of respiratory diseases. The results indicate that A. cochinchinensis may be utilized as a nutraceutical for respiratory diseases when the physiologically active substances of A. cochinchinensis are increased by further study.

• Food Engineering Progress
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• v.14 no.1
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• pp.65-74
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• 2010

Culture conditions of L. plantarum TJ-LP-002, the garlic resistant strain isolated from pakimchi (green onion kimchi), were investigated for the use of feed additives. Acetic acid, citric acid, lactic acid, and tartaric acid were detected in the culture supernatant, and especially the concentrations of lactic acid and acetic acid significantly increased during cultivation. The antimicrobial activity of L. plantarum TJ-LP-002 was not affected by proteases, calatase or cellulase, which showed that the antimicrobial activity might be due to the production of acids rather than proteinaceous antimicrobial substances. L. plantarum TJ-LP-002 was resistant to neomycin sulfate, spectinomycin dihydrochloride, and lincomycin hydrochloride, sensitive to streptomycin sulfate, and intermediate resistant to ampicillin trihydrate, chloramphenicol, erythromycin, tetracycline hydrochloride, and kanamycin sulfate. The optimum initial pH of medium, fermentation temperature and time for the cell growth and antibacterial activity were pH 7.0, 30${^{\circ}C}$ and 24hr, respectively. The optimal composition of culture medium for the cell growth and antimicrobial activity was 3%(w/v) glucose as a carbon source, 3%(w/v) yeast extract as a nitrogen source, and manganese sulfate and ammonium citrate as inorganic salts. The combinatorial supplementation of these inorganic salts, rather than sole addition as an inorganic salt, resulted in better antibacterial activity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.963-966
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• 2008

Twenty four bacterial strains were isolated and identified from human oral cavities. These strains were identified as genus 8 Moraxella, 1 Neisseria, 1 Proteus, 6 Bacillus, 4 Staphylococcus, 3 Branhamella and 1 Enterobacter. Two genuses are Gram-positive and four genuses are Gram-negative. In order to search for antimicrobial substances from natural plants, twenty one plant materials being made of perilla leaf as well as spices including garlic and ginger were used. The effects of these plant juices on the growth of oral bacterial strains were investigated. Only garlic juice inhibited the growth of seventeen bacterial strains belonging to 6 kinds of genus.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.63-65
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• 2008

The functional non-woven fabrics have been applied in various industry fields, such as clothing, hygiene, environment, medical and so forth. The functional non-woven fabrics were manufactured by meltblown and finishing processes. These functional non-woven fabrics were made of 2,000ppm nano-silver resin composite and polypropylene resin. Silver is one of the most universal antimicrobial substances. Nano-technology enables us to expand the surface area of silver particles markedly. Nano-silver particles were successfully produced less than 10nm in size. The functional non-woven fabrics including nano-silver particles showed excellent antibacterial activities against Staphylococcus aureus(ATCC 6538) and Klebsieila pneumoniae (ATCC 4352). From the results, nano-silver particels probably will be available as a good and safe antibiotic alternative.