• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.511-518
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• 1992

We subcloned a 58 KD chitinase gene of Serratia marcescens into Escherichia coli and investigated the expression and secretion of the chitinase. Chitinase was produced in E. coli by using its own promoter but the levels of enzyme were very low, less than 5 mU/m$\ell$. However, by the combined action of the chitinase and lac promoters, the chitinase activity increased up to about 80 mU/m$\ell$. The most of the chitinase produced in E. coli was localized in periplasm and the small amounts were observed in cytosol and culture medium. Intracellular chitinase activities increased in proportion to the growth of E. coli up to the early stationary phase but rapidly decreased thereafter, which was assumed to be degradation of the chitinase by E. coli proteolytic enzymes.

• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.237-251
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• 2020

Lactic acid bacteria prevent the contamination of food products by inhibiting proliferation of pathogenic bacteria. This is done mainly by the production of lactic acid and antimicrobial peptides (AMP_S) known as bacteriocins. The interest in these molecules resides in both their antimicrobial spectrum and safety for human health. The application of bacteriocins or producer strains has been considered to avoid the development of pathogenic bacteria, as most bacteriocins have significant inhibitory activity against food pathogens, such as Listeria monocytogenes. This article describes the classification, structure, mode of action, biosynthesis, and main applications of bacteriocins in different fields: agri-food, aquaculture, and medicine.

• The Research Journal of the Costume Culture
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• v.10 no.3
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• pp.213-235
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• 2002

The purpose of this study was to recognize the meanings of plastic language by analyzing the sign of the Graffiti depicted in western modern costumes. And the scope of this study was focused on analysing the costumes from 1980's when the Graffiti was recognized as one of the plastic arts. Graffiti was an unprofessional and covert desire of self-expression, having a close relation with our lives. It was used in diverse ways with repeating creation, development, and extinction, from expressing liveliness in Old Stone Age through describing symbolic meaning in the modern art. Graffiti means rude, humorous, or political writing and pictures on the walls of buildings. It's different from the delicate letters or pictures to inscript on the tree or rocks. Being introduced as part of Post-modernism in the 1970s, Graffiti was acknowledged as a new artistic action with the culture of hip-hop. In addition the Graffiti, the expression of sign was reflected artist's internal consciousness with boundless sign. The sign is something to transmit message from the nonverbal point of view, the oldest sign was the sign for petition or the expression of something as a primitive form. Sign can be defined as a framework of life inherited as a practice from the primitive age long past. Graffiti was cited as a concrete example of sign, theme of this paper, and general understanding on sign expression was pursued through free work which all artists present with essential and positive ways using signs, their own languages, and life style. The result of this study was summarized as follows: Since the end of the 20th century, a lot of fashion designers have represented symbolic images, such as letter and signs, as purely personal ways of expression through the western costumes. It was found that fashion designers of the Graffiti whose free work style from inherent inner consciousness might provide a basic framework to search for complex signs of modem costumes naturally understood life itself as plastic art, and sublimated human inherent desire and their inner world through their works.

• Biomedical Science Letters
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• v.14 no.3
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• pp.131-137
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• 2008

Adipogenesis is a complex sequence of events that culminates in the differentiation of fibroblast-like preadipocytes into specialized lipid-filled adipocytes and also involves a cascade of expression of many transcription factors such as peroxisome proliferator-activated receptor ${\gamma}(PPAR{\gamma})$ and CCAAT/enhancer-binding proteins (C/EBPs). $PPAR{\gamma}$ and C/EBPs transcriptionally transactivate adipocyte specific genes, including fatty acid transport protein (FAT/CD36) and leptin. To determine whether $17{\beta}$-estradiol modulates $C/EBP{\alpha}$ actions on adipogenesis in high fat diet-fed female ovariectomized (OVX) C57BL/6 mice, mice were treated with $17{\beta}$-estradiol for 7 days and the effects of $17{\beta}$-estradiol on adipose tissue mass and expression of adipocyte specific gene as well as $C/EBP{\alpha}$ were measured. Compared to vehicle-treated OVX control mice, OVX mice treated with $17{\beta}$-estradiol for 7 days had lower adipose tissue weights that were similar to weights in high fat diet-fed sham-operated (Sham) mice. OVX mice showed the increased expression of $C/EBP{\alpha}$ mRNA compared with Sham mice. However, $17{\beta}$-estradiol treatment in OVX mice inhibited OVX induced-$C/EBP{\alpha}$ activation, indicating that $17{\beta}$-estradiol may act as an inhibitor of $C/EBP{\alpha}$ action. Moreover, $17{\beta}$-estradiol decreased mRNA levels of adipocyte marker genes, such as lipoprotein lipase, FAT/CD36 and leptin, to levels in Sham mice. These results suggest that down-regulation of adipogenesis by $17{\beta}$-estradiol may be due to reduced adipose $C/EBP{\alpha}$ activities in female OVX C57BL/6 mice.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.87-91
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• 1996

The optimum temperature and pH for the enzyme activity were 45$^{\circ}C$ and 10.0, respectively. The enzyme was stable in a pH range of 5 to 10, and 62% of its activity was lost on heat treatment of 60$^{\circ}C$ for 20 min. The activity of the purified enzyme was inhibited by $Fe^{2+},\;Zn^{2+}\;and\;Pb^{2+}$, and slightly activated by $Mn^{2+}\;and\;Ca^{2+}$. ${\gamma}$-Chloromercuribenzoic acid, 2,4-dinitrophenol and $H_{2}O_{2}$ did not show inhibitroy effect on the lipolytic activity of the alkaline lipase but ethylenediaminetetraacetic acid inhibited the enzyem activity. This suggested that the enzyme have metal group in its active site. Sodium salts of bile acids stimulated the enzyme activity. Analysis of hydrolyzates of olive oil after the reaction revealed that Serratia liquefaciens AL-11 produced non-specific lipolytic enzyme.

• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.259-264
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• 1988

Two forms of extracellular inulinase, designated as PI and PII were detected in the crude enzyme preparation from n species of Pseudomonas isolated from soil. PI and PII were purified to homogeneity by ammonium sulfate fractionation, DEAE Sephadex A-50 chromatography, Sephadex G-100 and Sephadex G-200 gel filteration. Both isoenzymes catalyzed specifically and endowise the cleavage of the $\beta$-2,1-fructofranoside linkage of inulin, and displayed no action upon sucrose, raffinose and levan. The optimal pH values for the PI and PII enzyme were pH 5.5 and 6.0, respectively and the highest activity of the two enzymes was observed at 55$^{\circ}C$. The Km values of PI and PII were calculated to be 2$\times$10$^{-3}$M and 5$\times$10$^{-3}$M, respectively.

• Biomedical Science Letters
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• v.26 no.2
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• pp.66-74
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• 2020

This study was carried out to investigate the protective effect of crude saponin from Platycodon grandiflorum on Clinical chemical parameters in male rats acutely exposed to 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD). Crude saponin was prepared from Korean Platycodon grandiflorum with Diaion HP-20 adsorption chromatography after extraction of 80% ethanol at 75℃. The crude saponin was confirmed by thin layer chrmatography. When compared with ginseng saponins, the crude saponin had both a few number of saponins and a broad distribution. Forty male rats (200±20 g) were divided into 4 groups. Normal control (NC) group received vehicle and saline; TCDD-treated (TT) group received TCDD (40 ㎍/kg, single dose) intraperitoneally; Platycodon grandiflorum saponin (PG5 and PG10) groups received crude saponin 5 mg/kg and 10 mg/kg (p.o), respectively, for 2 weeks before 1 week of TCDD-exposure. Increase of body weight was retarded greatly by TCDD-exposure. Body weight of animals in TT group was significantly decrease after 2 days of TCDD-exposure. However, body weights of animals in PG groups increased through the experimental perimental period, although the increasing rate was slower than that of NC group. Increases in contents of blood glucose, total cholesterol and triglyceride (TG) and activities of amylase, lipase, AST, ALT and LDH by toxic action of TCDD were significantly attenuated by crude saponin from Platycodon grandiflorum (P<0.05). In conclusion, these results suggest that crude saponin prepared from Korean Platycodon grandiflorum might be a member of useful protective agents against TCDD, which is one of the environmental hormones.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.339-344
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• 1985

Cephalosporin C(CPC) inhibited the growth of Cephalosporium acremonium M-113, a potent CPC producer derived from C acremonium ATCC 20339. Similar inhibitory effects of CPC were also observed in growth of C. acremonium ATCC 20339 and ATCC 14553. Minimum inhibitory concentrations (MIC) of CPC on the growth of conidia and hyphae of C. acremonium M-113 were 200-500 and 3000-4000$\mu\textrm{g}$/$m\ell$ respectively in synthetic medium. MIC values were increased in complex media. The inhibitory effect of CPC was due to CPC-exerted inhibition of amino acids uptake by the cells. 3'-Group of CPC might be important in its inhibitory action. In audition, CPC itself could be utilized by the cells as a nitrogen source under nitrogen limited condition.

• Biomedical Science Letters
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• v.28 no.4
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• pp.334-339
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• 2022

African swine fever virus (ASFV) is a highly contagious and lethal pathogen that poses a threat to the global pork industry. The World Organization for Animal Health (WOAH) has placed strict surveillance measures for ASFV. The possibility of long-term survival of ASFV in raw meat or undercooked pork has been reported. Accordingly, the problem of secondary infection in food waste from households or waste disposal facilities has emerged, raising the need for ASFV monitoring of food waste. However, most of the previously reported ASFV gene detection methods are focused on clinical monitoring of pigs. There are very few cases in which their application in waste has been verified. Since ASFV diagnosis requires rapid monitoring and immediate action, loop-mediated isothermal amplification (LAMP) may be suitable, but this requires conformity assessment for LAMP to be used as a diagnostic technique. In this study, six LAMP methods were evaluated, and two methods (kit and manual) were recommended for use in diagnosing ASFV in food waste.

• Microbiology and Biotechnology Letters
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• v.20 no.3
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• pp.295-301
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• 1992

An alkaline protease producing microorganism was isolated from soil and identified as Streptomyces griseus HC-1141. The optimum pH and temperature for the purified enzyme activity were 8.0 and $60^{\circ}C$, respectively. The enzyme was relatively stable in the pH range of 7.0-9.0 and at the temperature below $60^{\circ}C$. The activity of purified enzyme was inhibited by $Hg^{2+}$, $Cu^{2+}$, $Zn^{2+}$, $Ba^{2+}$ and $Fe^{2+}$, whereas activated by $Mn^{2+}$ and $Ca^{2+}$. $\varepsilon$-Amino caproic acid, 2,4-dinitrophenol and iodine did not show inhibitory effect on the activity of alkaline protease, but p-chloromercuribenzoic acid, ethylendiaminetetraacetic acid showed inhibitory effect on the enzyme activity. These result suggested that the protease was metalloenzyme, and require a reactive SH group for the activity. The reaction of this enzyme follows typical Michaelis-Menten kinetics with the $K_m$ value of $2.229{\times}10^{-4}$M and the $V_{max}$ of $46.08 {\mu}$g/min for casein. The activation energy for the alkaline protease calculated by Arrhenius equation was 3.643 kcal/mol. This enzyme hydrolyzed casein more rapidly than the hemoglobin and egg albumin.