• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.339-346
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• 2007

The MJP1 bacterial strain, which possesses antifungal activity, was isolated from meju and identified as Bacillus subtilis based on its morphological and biochemical properties, as well as its 16S rRNA sequence. Antimicrobial activity was found against various species of Gram-positive bacteria, yeasts, and molds, including food-spoilage microorganisms. The antifungal activity was found to be stable after heat and proteolytic enzyme treatment, and in the pH range of $6.0{\sim}10.0$. The antibacterial activity was stable in the pH range of $6.0{\sim}10.0$, but about 50% of the activity was lost after 24 hr at $30^{\circ}C$. The antibacterial compound was also inactivated by proteolytic enzyme treatment, indicating its proteinaceous nature. The apparent molecular masses of the partially purified antifungal and antibacterial compounds, as indicated by using the direct detection method in Tricine-SDS-PAGE, were approximately 2.4 kDa and 4.5 kDa, respectively. These studies suggest that B. subtilis MJP1 produces two bacteriocin-like substances with antifungal and antibacterial activities.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.4 s.48
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• pp.503-507
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• 2004

The essential oil from Chamaecyparis obtusa was investigated for biological activities in anti-oxidative, anti-inflammation and antibacterial method, respectively. The Growth inhibitory effect of C. obtusa oil on the bacteria was evaluated with MIC (minimum inhibitory concentration), $IC_{50}\;(50\%$ inhibitory concentration), and paper disc method. Two kinds of gram positive strains and two kinds of gram negative strains were used in this study. Gram positive strains were B. subtilis and S. aureus. and Gram negative strains were E. coli and P. aeruginosa. Gram positive strains showed much more intensive effect than gram negative strains. Anti-oxidative effect was investigated with DPPH (1,1-diphenyl-2-picrylhidrazyl) in methanol based and $IC_{50}\;was\;0.78\%.$ Our results suggest that the essential oil from Chamaecyparis obtusa has effects on anti-bacterial, anti- oxidative and anti-inflammation in in vitro and in uiuo. Then this material could be expect synergic effect with other candidated extracts and oils.

• KSBB Journal
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• v.20 no.4
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• pp.285-290
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• 2005

Benzophenanthridine alkaloids - sanguinarine, chelirubine, macarpine, and chelerythrine are produced from Eschscholtzia californica (Californica Poppy, used as a sedative by Native Americans) and most of them are derived from dihydrosanguinarine. The properties of sanguinarine are the basis of its antimicrobial activity and its use in chemosurgery and skin cancer excision. For overproduction of sanguinarine from E. californica, yeast extract was used as elicitor and the elicited cell's metabolites were checked. Sanguinarine production was increased intracelluarly about 8 times in the cell and 5 times extracelluarly. We have peformed proteomic analysis of proteins sequentially extracted from E. califormica suspended cells which were cultured with elicitor, an increase of spot intensity was seen at 24 hours following elicitation. These proteins were separated by two-dimensional electrophoresis (2-DE). We found several spots that were expected to be related to benzophenanthridine alkaloids production by comparing the production profiles of metabolites such as sanguinarine. These results demonstrate the use of metabolite analysis as a tool for detecting target proteins related to metabolites production pathway.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.279-286
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• 2018

Citrus grandis Osbeck pericarp is used as tea, herbal medicine, etc., but is not commercialized in various ways. So, in this study, we identified potential for use of Citrus grandis Osbeck as health functional foods, cosmetics and food preservatives. Methanol extract of Citrus grandis Osbeck pericarp was fractionated with hexane, dichloromethane, ethyl acetate and butanol, to quantitatively analyze total phenol and flavonoid, and investigate antioxidative and enzyme inhibitory activities. Total phenol and flavonoid contents were highest in ethyl acetate fraction, FRAP and ORAC results also revealed highest activity in proportion to total phenol content. DPPH radical scavenging activity revealed that ethyl acetate, butanol and dichloromethane fraction manifested highest activity without significant difference. However, dichloromethane fraction revealed higher TEAC value and tyrosinase inhibitory activity than ethyl acetate fraction, and hexane fraction manifested best results with superoxide radical scavenging activity and ${\alpha}-glucosidase$ inhibitory activity. Antimicrobial activity also revealed best effect in dichloromethane and hexane fractions. So, based on the following results, use of dichloromethane fraction as material of natural functional cosmetics, ethyl acetate fraction for health functional foods, and hexane fractions for pharmaceuticals and food preservatives, would be most practical for product development.

• Journal of Dairy Science and Biotechnology
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• v.38 no.2
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• pp.70-88
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• 2020

Lactic acid bacteria (LAB) form an essential part of the intestinal microbiota of the human body and possess the ability to stabilize the intestinal microbiota, strengthen immunity, and promote digestion as well as intestinal synthesis of vitamins, amino acids, and proteins. Hence, LAB are currently widely used in various products. However, due to the indiscriminate overuse of antibiotics in humans and livestock, bacterial resistance to antibiotics has been increasing rapidly, which has led to serious problems in the treatment of bacterial infections. Additionally, several reports have revealed that antibiotic-resistant LAB may infect people whose immune systems are not fully developed or whose immune systems are temporarily weakened. Therefore, it is imperative to consider the possibility of antibiotic-resistant LAB causing diseases in humans and animals, investigate the mechanism of action between antibiotics and LAB, and determine the relevant regulations for the safe use of LAB.

• KSBB Journal
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• v.19 no.3
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• pp.215-220
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• 2004

A variety of solid bases such as inorganic bases, basic anion exchange resins, and resin-bound bases were tested as a catalyst for racemization of (S)-naproxen 2,2,2-trifluoroethyl thioester in isooctane at 45$^{\circ}C$. Among the various bases, DIAIOM WA30, which is a weakly basic anion exchange resin with a tertiary amine based on a highly porous type styrene-divinylbenzene copolymer, showed the highest catalytic activity. The second-order interconversion constant of DIAION WA30 was 8.6${\times}$10$\^$-4/ mM$\^$-1/h$\^$-1/ and about 3 times higher than that of trioctylamine under the same conditions. The rate of DIAION WA30-catalyzed racemization decreased with increasing an amount of water added to the reaction medium. Lipase-catalyzed kinetic resolution of racemic naproxen 2,2,2-trifluoroethyl thioester was successfully carried out under in situ racemization of substrate with DIAION WA30 in isooctane at 45$^{\circ}C$. More than 60% conversion and 99% enantiomeric excess for the desired (S)-naproxen product were obtained. Furthermore, such a solid base catalyst could be easily separated and reused in contrast to trioctylamine.

• 한국유가공학회:학술대회논문집
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• 2005.06a
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• pp.37-61
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• 2005

Microcapsules consisting of natural, biodegradable polymers for controlled and/or sustained core release applications are needed. Physicochemical properties of whey proteins suggest that they may be suitable wall materials in developing such microcapsules. The objectives of the research were to develop water-insoluble, whey protein-based microcapsules containing a model water-soluble drug using a chemical cross-linking agent, glutaraldehyde, and to investigate core release from these capsules at simulated physiological conditions. A model water soluble drug, theophylline, was suspended in whey protein isolate (WPI) solution. The suspension was dispersed in a mixture of dichloromethane and hexane containing 1% biomedical polyurethane. Protein matrices were cross-linked with 7.5-30 ml of glutaraldehyde-saturated toluene (GAST) for 1-3 hr. Microcapsules were harvested, washed, dried and analyzed for core retention, microstructure, and core release in enzyme-free simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) at 37$^{\circ}C$, A method consisting of double emulsification and heat gelation was also developed to prepare water-insoluble, whey protein-based microcapsules containing anhydrous milkfat (AMF) as a model apolar core. AMF was emulsified into WPI solution (15-30%, pH 4.5-7.2) at a proportion of 25-50% (w/w, on dry basis). The oil-in-water emulsion was then added and dispersed into corn oil (50 $^{\circ}C$)to form an O/W/O double emulsion and then heated at 85$^{\circ}C$ for 20 min for gelation of whey protein wall matrix. Effects of emulsion composition and pH on core retention, microstructure, and water-solubility of microcapsules were determined. Overall results suggest that whey proteins can be used in developing microcapsules for controlled and sustained core release applications.

• Journal of Life Science
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• v.29 no.12
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• pp.1408-1414
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• 2019

Enzymes are widely used in industrial applications such as detergents, food, feed production, pharmaceuticals and medical applications and major contributors to clean industrial products and processes. To screen, identify, and characterize the enzymes the zymography techniques are routinely used. The zymography technique is a simple, sensitive, and quantifiable technique that is widely used to detect functional enzymes following electrophoretic separation in sodium dodecyl sulfate (SDS)-polyacrylamide gels. The method is a versatile two-stage technique involving protein separation by electrophoresis followed by the detection of enzyme activity in polyacrylamide gels under non-reducing conditions. It is based on SDS-polyacrylamide gel (PAG) copolymerization with substrates, which are degraded by the hydrolytic enzymes restored in enzyme reaction buffer after the electrophoretic separation. Any kind of biological sample can be applied and analyzed on zymography, including culture supernatants of microbes, plants extracts, blood, tissue culture fluids, enzymes in foods extracts and metaproteome. The advantage of zymography is that it is possible to directly detect the protein with activity on the electrophoretic gel as well as confirm the activity at the nanogram level. Thus, this zymography technology can be applied in various fields. However, these advantages are rather disadvantageous and can often lead to experimental errors. In this review, the advantages, disadvantages, and problem solving of zymography technique are described.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.115-123
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• 2013

Food safety management should be based on scientific evidences. FAO and WHO presented risk analysis as one of four principles in food safety management. WTO also admits the self safety regulation only when it is made on the basis of risk assessment. Without scientific analysis, tracing and eliminating the cause of food poisoning is impossible. Research and development plays a key role to produce scientific evidences. The Korean government ran over 40 programs in 11 agencies from 2008 to 2010. However, there is no statistics on food safety R&D at present. In this research, food safety projects conducted from 2008 to 2010 are listed up by means of analysing National Science and Technology Information Service (NTIS). The analytical criteria are the name of programs, national standard classification of science and technology, and keywords. As result, Korea Food and Drug Administration, Ministry for Food, Agriculture, Forestry and Fisheries, and Rural Development Administration play major role in the food safety R&D. The portion of more than one year projects should rise up in order to achieve the data for risk assessment, which is strongly required to improve. Besides, the research should be deeper so as to publish more SCI papers. The R&D portfolio should be changed in direction to raise up the portion of biological hazards such as norovirus. In order to do so, a large number of food safety programs should be emerged. The categories of food safety management and the hygiene/quality management of the agricultural and livestock products in the national standard classification of science and technology should be emerged because they are set up reflecting agencies' interests in spite of few differences between them.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.527-547
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• 2020

Fish pathogens cause not only economic damages to fish farming but also infectious pathogens known as a zoonotic agent. Since the continued use of antibiotics to control fish pathogens entails side effects, materials of natural origin need to be developed. The purpose of this study is to discover coniferous essential oils with excellent antibacterial effects in order to develop antibiotic alternatives. We have extracted essential oils using hydro-distillation from the leaves of Abies holophylla, Pinus thunbergii, Pinus parviflora, Tsuga sieboldii, and Pinus rigitaeda, which are all Pinaceae family. And, we have evaluated antibacterial activity with the extracted essential oils against Edwardsiella tarda, Photobacterium damselae, Streptococcus parauberis, and Lactococcus garvieae, which are fish pathogens. As a result, the essential oils from A. holophylla and P. thunbergii showed the selectively strong antibacterial activity against E. tarda and P. damselae, which are gram-negative bacteria. From GC-MS analysis, it was identified that main component of A. holophylla essential oils are (-)-bornyl acetate (29.45%), D-limonene (20.47%), and camphene (11.73%), and that of P. thunbergii essential oils is α-pinene (59.81%). In addition, we found three compounds: neryl acetate, (-)-borneol, and (-)-carveol, which are oxygenated monoterpenes. These exist in a very small amount but exhibit the same efficacy as essential oil. Therefore, we expect that A. holophylla and P. thunbergii essential oils having excellent growth inhibitory effect against gram-negative fish pathogens can be used as biological products such as feed additives and fishery products.