• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.193-196
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• 2001

IL-18. formerly known as IGIF(interferon -gamma inducing factor), is structurally IL-l related but functionally IL-12 related pro-inflammatory cytokine. The human IL -18(hIL-lS), like IL-$1{\beta}$, is synthesized as a biologically inactive precursor of 24kDa lacking a signal peptide, and then cleaved into an active mature form by cystein protease IL-$1{\beta}$ converting enzyme (ICE: caspase- 1), We tested if the mature hIL -18 can be expressed and secreted into culture medium by transforming the forming gene construct consisting of a mature hIL-18 gene fused to signal peptide of rice amylase lA. Secondly, we were tested if the pro- IL-18 could be processed into a biologically active form by caspase-l like protease in plant. Cell suspension culture was established from the leaf-derived calli of transgenic tobacco plant. Southern and Northern blot analysis indicated the expression of both pro-hIL-18 and mature hIL-18 plant cells. Western blot analysis introduced the protein products of pro- hIL -18 and mhIL -18 were observed in transigenic cell lines. In addition, the molecular size of recombinant pro-hILl-18 and mhIL-18 were estimated to be 24kDa and 18kDa, respectively. ELISA revealed that the amount of pro- hIL -18 was 1.3ug per gram of fresh weight calli. Moreover, the presence of mhIL-18 was detected in the culture medium and it appeared to be 25ug/L.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.5
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• pp.100-106
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• 2004

$NO^3$-N removal was examined from July 2002 to December 2002 of a surface-flow constructed treatment wetland cell, which was a part of a treatment wetland system composed of four wetland cells and one distribution pond. The system was established on rice paddy near the Kohung Estuarine Lake located at the southern part of the Korean Peninsula. The lake and the paddy were formed by a salt marsh reclamation project. Effluent from a secondary-level treatment plant was funneled into the system. The investigated cell was created in June 2002. Its dimensions were 87 m in length and 14 m in width. It had an open water zone at its center, which was equivalent to 10 percent of its total area. Reeds(Phragmites australis) were transplanted from natural wetlands into the cell and their stems were cut at about 40 cm height from their bottom ends. Average 25 $m^3$/day of effluent from the plant was funneled into the cell by gravity flow and average 24.2$m^3$/day of its treated effluent was discharged into the Sinyang Stream flowing into the lake. Its water depth was maintained about 0.2 m and its hydraulic detention time averaged 5.2 days. The average height of the reed stems was 45.2 cm in July 2002 and 80.5 cm in September 2002. The number of stems averaged 40.3 stems/$m^2$ in July 2002 and 74.5 stems/$m^2$ in September 2002. The reeds were established initially well. $NO_3$-N loading rate of influent and effluent averaged 173.7 and $93.5mg/m2{\cdot}day$, respectively. Removal of $NO_3$-N averaged $80.2mg/m2{\cdot}day$ and its removal rate by mass was about 50 %. Considering the initial operation of the cell and the inclusion of the cold months of November and December in the analysis period, the $NO_3$-N removal rate was good.

• Molecules and Cells
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• v.23 no.1
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• pp.108-114
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• 2007

The mitogen-activated protein kinase (MAPK) signaling cascade is critical for regulating plant defense systems against various kinds of pathogen and environmental stresses. One component of this cascade, the MAP kinase kinases (MAPKK), has not yet been shown to be induced in plants following biotic attacks, such as those by insects and fungi. We describe here a gene coding for a blast (Magnaporthe grisea)- and insect (Nilaparvata lugens)-responsive putative MAPK kinase, OmMKK1 (Oryza minuta MAPKK 1), which was identified in a library of O. minuta expressed sequence tags (ESTs). Two copies of OmMKK1 are present in the O. minuta genome. They encode a predicted protein with molecular mass 39 kDa and pI of 6.2. Transcript patterns following imbibition of plant hormones such as methyl jasmonic acid (MeJA), ethephone, salicylic acid (SA) and abscisic acid (ABA), as well as exposure to methyl viologen (MV), revealed that the expression of OmMKK1 is related to defense response signaling pathways. A comparative analysis of OmMKK1 and its O. sativa ortholog OsMKK1 showed that both were induced by stress-related hormones and biotic stresses, but that the kinetics of their responses differed despite their high amino acid sequence identity (96%).

• The Plant Pathology Journal
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• v.33 no.5
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• pp.458-466
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• 2017

Xanthomonas oryzae pv. oryzae (Xoo), the causative agent of bacterial blight, is a major threat to rice productivity. Here, we performed RNA-Seq based transcriptomic analysis of Xoo transcripts isolated under in planta growth (on both susceptible and resistant hosts) and in vitro culture conditions. Our in planta extraction method resulted in successful enrichment of Xoo cells and provided RNA samples of high quality. A total of 4,619 differentially expressed genes were identified between in planta and in vitro growth conditions. The majority of the differentially expressed genes identified under in planta growth conditions were related to the nutrient transport, protease activity, stress tolerance, and pathogenicity. Among them, over 1,300 differentially expressed genes were determined to be secretory, including 184 putative type III effectors that may be involved in Xoo pathogenicity. Expression pattern of some of these identified genes were further validated by semi-quantitative RT-PCR. Taken together, these results provide a transcriptome overview of Xoo under in planta and in vitro growth conditions with a focus on its pathogenic processes, deepening our understanding of the behavior and pathogenicity of Xoo.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.72-78
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• 1985

A total of 220 tadpoles was captured in 6 areas and total 117 frogs, Rana nigromacuzata, were collected in 11 areas in Korea. They were examined for their infection status by the metacercariae of Fibricola seoulensis by peptic digestion technique and by histological observation with hematoBylineosin staining. This study was carried out from August, 1983 to September, 1984. Followings are the results. 1. The tadpoles of R. nigromaculata were positive for the metacercariae from 3.3% to 100% by area. The number of metacercariae per infected tadpole ranged from 1 to 584, and the mean number Per tadpole ranged from 7.6 to 221 by area. 2. The metacercariae from 16 tadpoles were counted by the body portion. A great majority of the metacercariae was collected from abdominal cavity, 98.3% of 484 counted larvae. And 6(1.2%) larvae were from proximal tail and 2(0.4%) from trunk. 3. Histological sections of tadpoles showed many metacercariae in abdominal cavity but none in other parts. The larvae were free in the spaces among intestinal loops or around primitive liver. A few larvae were in duct-like tissues near trunk wall. There was little infiltration of inaammatory cells. 4. The metacercarial infection rates of frogs ranged from 0% to 100% by area. The larval burden was 1 to 470 by infected frogs, and mean number ranged from 1 to 175.6 by area. By above results, it is suggested that the cercariae of F. seoulensis may infect R. nigromaculata already in the stage of tadpole. Almost all of the metacercariae were concentrated in abdominal cavity of tadpoles. According to the infection status of frogs, this nuke is prevalent almost nationwidely in rice paddies in Korea.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.324-332
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• 2016

A bacterial strain capable of hydrolyzing xylan was isolated from fermented soybean paste obtained from a domestic Buddhist temple, using enrichment culture with rice straw as a carbon source. The isolate, named YB-1301, was identified as Bacillus safensis on the basis of its DNA gyrase subunit B gene (gyrB) sequence. The xylanase productivity of strain YB-1301 was drastically increased when it was grown in the presence of wheat bran or various xylans. In particular, the maximum xylanase productivity reached above 340 U/ml in the culture filtrate from LB broth supplemented with only birchwood xylan at shake-flask level. The xylanase production was significantly induced by xylans at the stationary growth phase in LB medium containing xylan, whereas only a small amount of xylanase was constitutively produced from cells grown in LB medium with no addition of xylan. Furthermore, xylanase biosynthesis was induced more rapidly by the enzymatically hydrolyzed products of xylan than by the non-hydrolyzed xylan. In addition, the xylanase in the culture filtrate of B. safensis YB-1301 was found to have optimal activity at 55℃ and pH 6.5–7.0.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1557-1567
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• 2012

Glutathione reductase (GR, E.C. 1.6.4.2) is an important enzyme that reduces glutathione disulfide (GSSG) to a sulfydryl form (GSH) in the presence of an NADPH-dependent system. This is a critical antioxidant mechanism. Owing to the significance of GR, this enzyme has been examined in a number of animals, plants, and microbes. We performed a study to evaluate the molecular properties of GR (OsGR) from rice (Oryza sativa). To determine whether heterologous expression of OsGR can reduce the deleterious effects of unfavorable abiotic conditions, we constructed a transgenic Saccharomyces cerevisiae strain expressing the GR gene cloned into the yeast expression vector p426GPD. OsGR expression was confirmed by a semiquantitative reverse transcriptase polymerase chain reaction (semiquantitative RT-PCR) assay, Western-blotting, and a test for enzyme activity. OsGR expression increased the ability of the yeast cells to adapt and recover from $H_2O_2$-induced oxidative stress and various stimuli including heat shock and exposure to menadione, heavy metals (iron, zinc, copper, and cadmium), sodium dodecyl sulfate (SDS), ethanol, and sulfuric acid. However, augmented OsGR expression did not affect the yeast fermentation capacity owing to reduction of OsGR by multiple factors produced during the fermentation process. These results suggest that ectopic OsGR expression conferred acquired tolerance by improving cellular homeostasis and resistance against different stresses in the genetically modified yeast strain, but did not affect fermentation ability.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.1
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• pp.60-68
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• 2010

This study was conducted to evaluate the effects of lotus leaf powder on the qualitative characteristics of Jeung-Pyun (traditional Korean fermented rice cake). To achieve the highest volume and specific volume, 4% lotus leaf powder was required. However the moisture content dropped as the lotus leaf powder was added to the mixture. In addition, pH of Jeung-Pyun decreased the longer it was allowed to ferment, but the pH increased after steaming. We also evalusted the transparency of Jeung-Pyun as lotus leaf powder was added. As the lotus leaf powder was added, the L-value decreased and the a-value and b-value increased. Additionally, the hardness, chewiness and brittleness of Jeung-Pyun increased as more lotus leaf powder was added (p<0.05), but the springiness and cohesiveness did not change. The Jeung-Pyun also became darker and the cells became less uniform as the level of lotus powder increased. A control group of Jeung-Pyun without lotus leaf powder produced the strongest takju flavor, while the sourness decreased as more lotus leaf powder was added. The addition of 2% and 4% lotus leaf powder resulted in the chewiest and most flexible Jeung-Pyun. The results of this evaluation showed that Jeung-Pyun with 4% lotus leaf powder had the best appearance, flavor, texture, and taste, and was generally the most preferred Jeung-Pyun. Finally, SEM evaluation of the Jeung-Pyun, revealed that, higher levels of lotus leaf powder resulted in larger and less consistent pores and bubbles.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.576-581
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• 2005

Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals, and reduces the phosphorus pollution of animal waste. We have engineered the cell surface of the yeast. Saccharomyces cerevisiae, by anchoring active fungal phytase on its cell wall, in order to apply it as a dietary supplement containing bioconversional functions in animal foods and a whole cell bio-catalyst for the treatment of waste. The phytase gene (phyA) of Aspergillus niger with a signal peptide of rice amylase 1A (Ramy1A) was fused with the gene encoding the C-terminal half (320 amino acid residues from the C-terminus) of yeast ${\alpha}-agglutinin$, a protein which is involved in mating and is covalently anchored to the cell wall. The resulting fusion construct was introduced into S. cerevisiae and expressed under the control of the constitutive glyceraldehydes-3-phosphate dehydrogenase (GPD) promoter. Phytase plate assay revealed that the surface-engineered cell exhibited a catalytically active opaque zone which was restricted to the margin of the colony. Additionally, the phytase activity was detected in the cell fraction, but was not detected in the culture medium when it was grown in liquid. These results indicate that the phytase was successfully anchored to the cell surface of yeast and was displayed as its active form. The amount of recombinant phytase on the surface of yeast cells was estimated to be 16,000 molecules per cell.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.469-472
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• 2002

Solid state fermentation was performed for the production of entomopathogenic fungus Metarhizium anisopliae HY-2 using wheat bran media containing rice bran. Fungal growth in a solid state fermentation system was estimated by viable cell count, spore count, and mycelial biomass. It was used chemical method measuring N-acetyl-glucosamine (chitin) content for estimating of mycelial biomass. In static flask culture, viable cell reached 2.40 ${\times}$ $10^8$ cfu/g at 23 days of culture at $27^{\circ}C$ and then mycelial biomass was 41.59 mg/g. Specific growth rate(${\mu}$ max) was 0.0418 $h^{-1}$ between 3 and 9 days when estimated by viable cell count and was 0.00976 $h^{-1}$ between 9 and 17 days when N-acetylglucosamine content was measured. Viable cells reached 1.12 ${\times}$ $10^8$ cfu/g in polypropylene-bag at 28 days of culture at $27^{\circ}C$. Formulated microbial pesticide containing M. anisopliae HY-2 were tested their bio-activity against Chestnut Brown Chafer (Adoretus tenuimaculatus). The protection rate of the liquid culture showed 13 ${\sim}$ 26 % with 1st to 3rd instar, and spore suspension of M. anisopliae HY-2 showed 56 ${\sim}$ 64%. Conidia produced by large scale solid-state fermentation showed 20 ${\sim}$ 27 % activity 60 ${\sim}$ 64 % with M. anisopliae HY-2.