• Korean Journal of Microbiology
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• v.54 no.1
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• pp.79-80
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• 2018

Citrobacter freundii is a facultative anaerobic and a Gram-negative bacterium of Enterobacteriaceae family, and is an opportunistic pathogen. Bacteriophages infecting C. freundii can be an effective treatment for C. freundii infections. Here, the complete genomic sequence is announced for a lytic bacteriophage CF1 infecting C. freundii isolates.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.175-181
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• 2011

Effective Agrobacterium-mediated transformation of Trichoderma harzianum could be achieved using the $Al_2O_3$ particles-abraded mycelia pellets. Transformation efficiency, as percents for the number of hygromcin-resistant mycelia pellets out of total pellets tested, was about 20 in average for $Al_2O_3$ experiment. No transformed mycelium was obtained from the intact mycelia pellets. After second round of antibiotics selection, DNA integration of hygromycin resistant gene and the expression of target gene could be confirmed by PCR and RT PCR, respectively. This is the first report of Agrobacterium-mediated T. harzianum transformation.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.79-86
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• 2017

Microbes in forest are very important due to not only to enhance soil fertility but also maintain a healthy ecosystem by supplying the energy available to living organisms by producing various kinds of enzymes related to degradation of lignocellulosic biomass. In order to isolate a lignocellulosic biomass degrading bacterial strain from the Jurassic park located in Gyeongnam National University of Science and Technology, We used the Luria-Bertani-Carboxymethyl cellulose (CMC) agar trypan blue method containing 0.4 % carboxymethyl cellulose and 0.01 % trypan blue. As a result, we isolated a bacterial strain showing both activity on the CMC and xylan. To identify the isolated strain, 16S rRNA sequencing and API kit analysis were used. The isolated strain turned out to belong to Bacillus species and then named Bacillus sp. GJY. In the CMC zymogram analysis, it showed that one active band of about 28kDa in size is present. Xylan zymogram analysis also showed to have one active band of about 25kDa in size. The optimal growth temperature of Bacillus sp. GJY was $37^{\circ}C$. The maximal activities of CMCase and xylanase were 12 hour after incubation. The optimal pH and temperature for CMCase were 5.0 and $40^{\circ}C$, respectively, whereas the optimal pH and temperature for xylanase was 4.0 and $40^{\circ}C$. Both activities for CMCase and xylanase showed to be thermally stable at 40and $50^{\circ}C$, while both activities rapidly decreased at over $60^{\circ}C$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.575-580
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• 2017

This study analyzed the effects of RGG box of hnRNP A1 on its subcellular localization and stabilization of hnRNP A1 over a three year period from October 2014. First, a 6R/K mutation in RGG box was generated, and pcDNA1-HA-hnRNP A1(6R/K) was constructed. The subcellular localization of hnRNP A1(6R/K) from the HeLa cells transfected with this plasmid DNA was analyzed by immunofluorescence microscopy. HA-hnRNP A1(6R/K) was found to exhibit nuclear and cytoplasmic fluorescence. The stability of hnRNP A1(6R/K) was checked by Western blot analysis using the expressed protein from the HeLa cells transfected with the pcDNA1-HA-hnRNP A1(6R/K). The results show that HA-hnRNP A1(6R/K) has a smaller size. These confirm that HA-hnRNP A1(6R/K) is localized both in the nuclear and cytoplasm, not because 6R/K mutation affects the nuclear localization of hnRNP A1, but because 6R/K mutation causes hnRNP A1(6R/K) to cleave at the mutation or near the mutation site. The cleaved protein fragment, which lacks the M9 domain (i.e. nuclear localization signal of hnRNP A1), did not exhibit nuclear fluorescence. This suggests that the arginines of RGG box in hnRNP A1 play an important role in stabilizing hnRNP A1. An analysis of the RNA-binding ability of hnRNP A1(6R/K) expressed and purified from bacteria will be a subsequent research project.

• Journal of the Korean Dietetic Association
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• v.25 no.3
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• pp.217-228
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• 2019

There have been no published studies concerning the anti-inflammatory effects of corn silk on colon cancer cells. Thus, this study was conducted to investigate the effect of corn silk extract containing high levels of maysin on inflammation and its mechanism of action in colon cancer cells. SW 480 human colon cancer cells were treated with $1{\mu}g/mL$ of lipopolysaccharide (LPS) to induce inflammation, and next they were treated with different concentrations of corn silk extract (0, 5, 10 and $15{\mu}g/mL$). The concentrations of nitric oxide (NO) were determined. The mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor ${\alpha}$ ($TNF-{\alpha}$), interleukin-1beta ($IL-1{\beta}$) and interleukin-6 (IL-6), were determined. Western blot analysis was performed to determine the protein expressions of nuclear factor-kappa B ($NF-{\kappa}B$) and mitogen-activated protein kinases, and the latter consists of extracellular signal-related kinase (ERK), c-jun NH2-terminal kinase (JNK) and p38 MAP kinase (p38). The concentration of NO and the mRNA expression of iNOS were significantly and dose-dependently decreased in the corn silk-treated groups (P<0.05). The mRNA expression of $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6 were significantly increased in the LPS-treated group (P<0.05), but these expressions were significantly and dose-dependently decreased in the corn silk treated groups (P<0.05). The protein expressions of $NF-{\kappa}B$ (in a dose-dependent fashion), ERK (at 10 and $15{\mu}g/mL$), JNK (at $15{\mu}g/mL$) and p38 (at 10 and $15{\mu}g/mL$) were significantly decreased with corn silk treatments (P<0.05). In conclusion, corn silk extract containing high levels of maysin seems to inhibit the LPS-induced inflammatory responses in SW480 colon cancer cells via the $NF-{\kappa}B$ pathway.

• Journal of Animal Science and Technology
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• v.52 no.1
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• pp.65-70
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• 2010

A bacterium producing acidic cellulase was isolated from pig feces. The isolate, ATC6 strain, was found to be Gram-positive, non-motile, catalase-positive, and spore-forming stain. Under an electron microscope, the cells were observed to be rod-shaped. The isolate was identified as Bacillus amyloliquefaciens ATC6 on the basis of morphological and biochemical properties as well as 16S rRNA gene sequences. Optimum pH and temperature for the cellulase activity of the culture supernatant of B. amyloliquefaciens ATC6 were found to be pH 4.5 and $55^{\circ}C$, respectively. More than 80% of its maximum activity was maintained at pH 4.0. The cellulase activity was maintained at temperatures ranging from 35 to $55^{\circ}C$ after 2 h incubation at pH 4.5, whereas it's activity decreased rapidly at $65^{\circ}C$.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.325-330
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• 2007

RNase E is an essential Escherichia coli endoribonuclease that plays a major role in the decay and processing of a large fraction of RNAs in the cell and expression of N-terminal domain consisted of 1-498 amino acids (N-Rne) is sufficient to support normal cellular growth. By utilizing these properties of RNase E, we developed a genetic system to screen for amino acid substitutions in the catalytic domain of the protein (N-Rne) that lead to various phenotypes. Using this system, we identified three kinds of mutants. A mutant N-Rne containing amino acid substitution in the S1 domain (I6T) of the protein was not able to support survival of E. coli cells, and another mutant N-Rne with amino acid substitution at the position 488 (R488C) in the small domain enabled N-Rne to have an elevated ribonucleolytic activity, while amino acid substitution in the DNase I domain (N305D) only enabled N-Rne to support survival of E. roli cells when the mutant N-Rne was over-expressed. Analysis of copy number of ColEl-type plasmid revealed that effects of amino acid substitution on the ability of N-Rne to support cellular growth stemmed from their differential effects on the ribonucleolytic activity of N-Rne in the cell. These results imply that the genetic system developed in this study can be used to isolate mutant RNase E with various phenotypes, which would help to unveil a functional role of each subdomain of the protein in the regulation of RNA stability in E. coli.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.270-277
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• 2010

In order to manufacture Bacillus cereus-free fermented soybean products, an antimicrobial agentproducing isolate against B. cereus was obtained from 150 traditionally fermented soybean products. The morphological and biochemical tests and the phylogenetic relationship among 16S rRNA gene sequences indicated that the isolate named as the strain SCK 121057 was most closely related to Bacillus licheniformis. The B. licheniformis isolate began to produce the antimicrobial agent after 48 h of incubation. The agent was nonproteinaceous and insensitive to heat, long term storage and protease K. Electron microscopic observation indicated that the agent attacked the membrane of B. cereus, leaving the ghost cell. The isolate inhibited growth of B. subtilis, Lactobacillus brevis and various types of pathogenic strains including Escherichia coli, E. faecalis, Micrococcus luteus, Staphylococcus aureus, Aspergillus flavus, A. ochraceus, and A. parasiticus as well as B. cereus. After coinoculation of B. licheniformis SCK 121057 and B. cereus in the ratio (as the basis of CFU/g sample) of 10 to 1 on the surface of cooked soybeans, cell numbers of B. cereus had been dramatically reduced after 31 days of incubation compared to those of single inoculation of B. cereus.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.225-230
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• 1989

Infectious Pancreatic Necrosis Virus (IPNV) is one of the most important pathogens for inland fish farming and had been first reported in Korea from returning adult chum salmon (Oncorhynchus keta) at hatcheries on the east coast. During the past years, several viruses identified as IPNV were isolated not only from chum salmon, but also from gold fish (Carassius auratus), eel(Anguilla japonica), and rainbow trout (Salmo gairdneri). An isolate, coded DRT, from fingerlings of pan-cultured rainbow trout in Daechung Dam showed different serotype from three known reference serogroups of IPNV such as VR-299, Sp, and Ab. Antisera to three of these serotypes, however, partially neutralized the infectivity of this isolate. Anti-Sp type was rather effective than either anti-VR-299 or anti-Ab, implying DRT could be more closely related to Sp. DRT has been purified and its RNA genome segments were compated showing that the isolate does not belong to any of known serogroups even with some common antigenicity.

• Research in Plant Disease
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• v.21 no.4
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• pp.321-325
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• 2015

A rapid and simple RT-PCR diagnosis method for detection of Rice stripe virus (RSV), one of major virus infecting rice, was developed using porous ceramic cubes in this study. The porous ceramic cube can rapidly absorb biological molecules such as small-sized proteins and nucleic acid fragments into its pores. We examined whether this ability of porous ceramic cubes could be applied for isolating viral nucleic acids or particles from the RSV- infected plant tissues. In this study, we found that the porous ceramic cube was capable of absorbing a detection level of viruses from the rice tissues infected with RSV and established RT-PCR-based RNA diagnosis method using porous ceramic cubes.