Publications by authors named "Jin-Seog Kim"

24 Publications

  • Page 1 of 1

Gravimetric Standard Gas Mixtures for Global Monitoring of Atmospheric SF.

Anal Chem 2017 11 7;89(22):12068-12075. Epub 2017 Nov 7.

Global Monitoring Division, National Oceanic and Atmospheric Administration , 325 Broadway, Boulder, Colorado 80305, United States.

In this study, standard gas mixtures of SF in synthetic air were gravimetrically developed as a suite consisting of 6 mixtures with mole fractions of SF ranging from 5 to 15 pmol/mol. For precision in weighing the gas fills, an automatic weighing system coupled with a high sensitivity mass balance was used and a gravimetry precision of 3 mg (2σ) was achieved. Impurity profiles of the raw gases were determined by various analyzers. In particular, sub pmol/mol levels of SF in the matrix components (N, O, and Ar) were carefully measured, since the mole fraction of SF in the final step can be significantly biased by this trace amount of SF in the raw gases of the matrix components. Gravimetric dilution of SF by purity-assessed N was performed in 6 steps to achieve a mole fraction of 440 pmol/mol. In the final step, O and Ar were added to mimic the atmospheric composition. Gravimetric fractions of SF and the associated standard uncertainty in each step were computed according to the ISO 6142 and JCGM 100:2008, respectively, and validated experimentally. Eventually, the SF fraction uncertainty of the standard gas mixtures combined by uncertainties of gravimetric preparation and verification measurements were found to be nominally 0.08% at a 95% confidence interval. A comparison with independent calibration standards from NOAA shows agreement within 0.49%, satisfying the extended WMO compatibility goal, 0.05 ppt.
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http://dx.doi.org/10.1021/acs.analchem.7b02545DOI Listing
November 2017

Bioethanol Production from by Fed-Batch Fermentation Using KCTC7017.

J Microbiol Biotechnol 2017 Jun;27(6):1112-1119

Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea.

The aim of this study was to develop a potential process for bioethanol production from (HR), a filamentous freshwater alga, using (KCTC7017). From the sugar solutions prepared by the four different hydrolysis methods, bioethanol production ranged from 11.0 g/100 g dried material (acid hydrolysis) to 22.3 g/ 100 g dried material (enzymatic hydrolysis, EH). Bioethanol was fermented from a highly concentrated sugar solution obtained by a decompression-mediated (vacuum) enrichment method (VE). As the results, ethanol was more efficiently produced from HR when sugar solutions were concentrated by VE following EH (EH/VE). Using multiple feeding of the sugar solution prepared by EH/VE from HR, ethanol reached up to a concentration of 54.3 g/l, corresponding to 24.9 g/100 g dried material, which attained the economic level of product concentration (approximately 5%). The results indicate that by using HR, it is feasible to establish a bioethanol production process, which is effective for using microalgae as the raw material for ethanol production.
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http://dx.doi.org/10.4014/jmb.1607.07066DOI Listing
June 2017

Comparison of halocarbon measurements in an atmospheric dry whole air sample.

Elementa (Wash D C) 2015;3. Epub 2015 Nov 3.

Scripps Institution of Oceanography, La Jolla (SIO), University of California, San Diego, La Jolla, California, United States.

The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%.
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http://dx.doi.org/10.12952/journal.elementa.000075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4702251PMC
November 2015

Roles of chemical metrology in electronics industry and associated environment in Korea: a tutorial.

Talanta 2015 Mar 24;134:284-291. Epub 2014 Nov 24.

Center for Inorganic Analysis, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-Gu, Daejeon 305-340, Republic of Korea.

Chemical metrology is gaining importance in electronics industry that manufactures semiconductors, electronic displays, and microelectronics. Extensive and growing needs from this industry have raised the significance of accurate measurements of the amount of substances and material properties. For the first time, this paper presents information on how chemical metrology is being applied to meet a variety of needs in the aspects of quality control of electronics products and environmental regulations closely associated with electronics industry. For a better understanding of the roles of the chemical metrology within electronics industry, the recent research activities and results in chemical metrology are presented using typical examples in Korea where electronic industry is leading a national economy. Particular attention is paid to the applications of chemical metrology for advancing emerging electronics technology developments. Such examples are a novel technique for the accurate quantification of gas composition at nano-liter levels within a MEMS package, the surface chemical analysis of a semiconductor device. Typical metrological tools are also presented for the development of certified reference materials for fluorinated greenhouse gases and proficiency testing schemes for heavy metals and chlorinated toxic gas in order to cope properly with environmental issues within electronics industry. In addition, a recent technique is presented for the accurate measurement of the destruction and removal efficiency of a typical greenhouse gas scrubber.
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http://dx.doi.org/10.1016/j.talanta.2014.11.030DOI Listing
March 2015

Metabolic versatility of toluene-degrading, iron-reducing bacteria in tidal flat sediment, characterized by stable isotope probing-based metagenomic analysis.

Environ Microbiol 2014 Jan 10;16(1):189-204. Epub 2013 Oct 10.

Department of Microbiology, Chungbuk National University, Cheongju, 361-763, Korea.

DNA stable isotope probing and metagenomic sequencing were used to assess the metabolic potential of iron-reducing bacteria involved in anaerobic aromatic hydrocarbon degradation in oil spill-affected tidal flats. In a microcosm experiment, (13) C-toluene was degraded with the simultaneous reduction of Fe(III)-NTA, which was also verified by quasi-stoichiometric (13) C-CO2 release. The metabolic potential of the dominant member affiliated with the genus Desulfuromonas in the heavy DNA fraction was inferred using assembled scaffolds (designated TF genome, 4.40 Mbp with 58.8 GC mol%), which were obtained by Illumina sequencing. The gene clusters with peripheral pathways for toluene and benzoate conversion possessed the features of strict and facultative anaerobes. In addition to the class II-type benzoyl-CoA reductase (Bam) of strict anaerobes, the class I-type (Bcr) of facultative anaerobes was encoded. Genes related to the utilization of various anaerobic electron acceptors, including iron, nitrate (to ammonia), sulfur and fumarate, were identified. Furthermore, genes encoding terminal oxidases (caa3 , cbb3 and bd) and a diverse array of genes for oxidative stress responses were detected in the TF genome. This metabolic versatility may be an adaptation to the fluctuating availability of electron acceptors and donors in tidal flats.
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http://dx.doi.org/10.1111/1462-2920.12277DOI Listing
January 2014

Production of L- and D-lactic acid from waste Curcuma longa biomass through simultaneous saccharification and cofermentation.

Bioresour Technol 2013 Oct 15;146:35-43. Epub 2013 Jul 15.

Department of Green Chemistry and Environmental Biotechnology, University of Science and Technology, 217 Gajungro, Yuseong-gu, Daejeon 305-333, Republic of Korea; Research Center for Biobased Chemistry, Division of Convergence Chemistry, Korea Research Institute of Chemical Technology, Daejeon 305-600, Republic of Korea. Electronic address:

Simultaneous saccharification and cofermentation (SSCF) of Curcuma longa waste biomass obtained after turmeric extraction to L- and D-lactic acid by Lactobacillus coryniformis and Lactobacillus paracasei, respectively, was investigated. This is a rich, starchy, agro-industrial waste with potential for use in industrial applications. After optimizing the fermentation of the biomass by adjusting nitrogen sources, enzyme compositions, nitrogen concentrations, and raw material concentrations, the SSCF process was conducted in a 7-l jar fermentor at 140 g dried material/L. The maximum lactic acid concentration, average productivity, reducing sugar conversion and lactic acid yield were 97.13 g/L, 2.7 g/L/h, 95.99% and 69.38 g/100 g dried material for L-lactic acid production, respectively and 91.61 g/L, 2.08 g/L/h, 90.53% and 65.43 g/100 g dried material for D-lactic acid production, respectively. The simple and efficient process described in this study could be utilized by C. longa residue-based lactic acid industries without requiring the alteration of plant equipment.
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http://dx.doi.org/10.1016/j.biortech.2013.07.035DOI Listing
October 2013

New chemical constituents from Oryza sativa straw and their algicidal activities against blue-green algae.

J Agric Food Chem 2013 Aug 14;61(34):8039-48. Epub 2013 Aug 14.

Department of Applied BioScience, College of Life and Environmental Sciences, Konkuk University, Seoul 143-701, South Korea.

Five new constituents, 5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-β-D-xylopyranosyl-(2a→1b)-2a-O-β-D-xylopyranosyl-(2b→1c)-2b-O-β-D-xylopyranosyl-2c-octadecanoate (1), 5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-2d-octadecanoate (2), kaempferol-3-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-2d-hexadecanoate (3), methyl salicylate-2-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-(2d→1e)-2d-O-α-D-xylopyranosyl-(2e→1f)-2e-O-α-D-xylopyranosyl-(2f→1g)-2f-O-α-D-xylopyranosyl-(2g→1h)-2g-O-α-D-xylopyranosyl-2h-geranilan-8',10'-dioic acid-1'-oate (4), and oleioyl-β-D-arabinoside (5), along with eight known compounds, were isolated from a methanol extract of Oryza sativa straw. The structures of the new compounds were elucidated using one- and two-dimensional NMR spectroscopies in combination with IR, ESI/MS, and HR-ESI/FTMS. In bioassays with blue-green algae, the efficacies of the algicidal activities of the five new compounds (1-5) were evaluated at concentrations of 1, 10, and 100 mg/L. Compound 5 had the highest growth inhibition (92.6 ± 0.3%) for Microcystis aeruginosa UTEX 2388 at a concentration of 100 ppm (mg/L). Compound 5 has high potential for the ecofriendly control of weeds and algae harmful to water-logged rice.
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http://dx.doi.org/10.1021/jf402145uDOI Listing
August 2013

D-lactic acid production from dry biomass of Hydrodictyon reticulatum by simultaneous saccharification and co-fermentation using Lactobacillus coryniformis subsp. torquens.

Biotechnol Lett 2012 Dec 30;34(12):2235-40. Epub 2012 Aug 30.

University of Science and Technology, Research Center for Biobased Chemistry, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea.

D-lactic acid production from dry biomass of the microalga, Hydrodictyon reticulatum, was carried out in a 5-l jar fermentor (initial pH 6, 34 °C using CaCO(3) as a neutralizing agent) through simultaneous saccharification and co-fermentation using the Lactobacillus coryniformis subsp. torquens. After 36 h, 36.6 g lactic acid/l was produced from 80 g H. reticulatum/l in the medium containing 3 g yeast extract/l and 3 g peptone/l in the absence of mineral salts. The maximum productivity, average productivity and yield were 2.38 g/l h, 1.02 g/l h and 45.8 %, respectively. The optical purity of D-Lactic acid ranged from 95.8-99.6 %. H. reticulatum is thus a promising biomass material for the production of D-Lactic acid.
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http://dx.doi.org/10.1007/s10529-012-1023-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3486992PMC
December 2012

Cultivation of a highly enriched ammonia-oxidizing archaeon of thaumarchaeotal group I.1b from an agricultural soil.

Environ Microbiol 2012 Jun 20;14(6):1528-43. Epub 2012 Apr 20.

Department of Microbiology, Chungbuk National University, 12 Gaeshin-dong, Heungduk-gu, Cheongju, Korea.

Nitrification of excess ammonia in soil causes eutrophication of water resources and emission of atmospheric N(2) O gas. The first step of nitrification, ammonia oxidation, is mediated by Archaea as well as Bacteria. The physiological reactions mediated by ammonia-oxidizing archaea (AOA) and their contribution to soil nitrification are still unclear. Results of non-culture-based studies have shown the thaumarchaeotal group I.1b lineage of AOA to be dominant over both AOA of group I.1a and ammonia-oxidizing bacteria in various soils. We obtained from an agricultural soil a highly enriched ammonia-oxidizing culture dominated by a single archaeal population [c. 90% of total cells, as determined microscopically (by fluorescence in situ hybridization) and by quantitative PCR of its 16S rRNA gene]. The archaeon (termed 'strain JG1') fell within thaumarchaeotal group I.1b and was related to the moderately thermophilic archaeon, Candidatus Nitrososphaera gargensis, and the mesophilic archaeon, Ca. Nitrososphaera viennensis with 97.0% and 99.1% 16S rRNA gene sequence similarity respectively. Strain JG1 was neutrophilic (growth range pH 6.0-8.0) and mesophilic (growth range temperature 25-40°C). The optimum temperature of strain JG1 (35-40°C) is > 10°C higher than that of ammonia-oxidizing bacteria (AOB). Membrane analysis showed that strain JG1 contained a glycerol dialkyl glycerol tetraether, GDGT-4, and its regioisomer as major core lipids; this crenarchaeol regioisomer was previously detected in similar abundance in the thermophile, Ca. N. gargensis and has been frequently observed in tropical soils. Substrate uptake assays showed that the affinity of strain JG1 for ammonia and oxygen was much higher than those of AOB. These traits may give a competitive advantage to AOA related to strain JG1 in oligotrophic environments. (13) C-bicarbonate incorporation into archaeal lipids of strain JG1 established its ability to grow autotrophically. Strain JG1 produced a significant amount of N(2) O gas - implicating AOA as a possible source of N(2) O emission from soils. Sequences of archaeal amoA and 16S rRNA genes closely related to those of strain JG1 have been retrieved from various terrestrial environments in which lineage of strain JG1 is likely engaged in autotrophic nitrification.
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http://dx.doi.org/10.1111/j.1462-2920.2012.02740.xDOI Listing
June 2012

Production of l-lactic acid from a green microalga, Hydrodictyon reticulum, by Lactobacillus paracasei LA104 isolated from the traditional Korean food, makgeolli.

Bioresour Technol 2012 Apr 26;110:552-9. Epub 2012 Jan 26.

University of Science and Technology, Chemical Biotechnology Research Center, Korea Research Institute of Chemical Technology, Daejeon 305-600, Republic of Korea.

The freshwater microalga, Hydrodictyon reticulum, that contained 47.5% reducing sugars including 35% glucose was used as substrate for the production of l-lactic acid (LA) by LA-producing bacteria. Lactobacillus paracasei LA104 was selected for fermentation in a 5-l fermentor since it was able to grow at pH 3, 60g LA/l, 200g glucose/l, 125g NaCl/l, and 45°C and produced over 97.3% optically pure l-lactic acid with glucose as a substrate. Simultaneous saccharification and cofermentation from H. reticulum to l-LA using LA104 was investigated in a jar fermentor. The yield reached 46g/100g H. reticulum dry material, with a final concentration of 37.11g/l and a productivity of 1.03g/l/h. This is the first report of the production of l-LA from a microalga, and H. reticulum could be a potential feedstock for large-scale production of l-LA by LA104.
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http://dx.doi.org/10.1016/j.biortech.2012.01.079DOI Listing
April 2012

Enrichment and characterization of an autotrophic ammonia-oxidizing archaeon of mesophilic crenarchaeal group I.1a from an agricultural soil.

Appl Environ Microbiol 2011 Dec 14;77(24):8635-47. Epub 2011 Oct 14.

Department of Microbiology, Chungbuk National University, 12 Gaeshin-dong, Heungduk-gu, Cheongju 361-763, South Korea.

Soil nitrification is an important process for agricultural productivity and environmental pollution. Though one cultivated representative of ammonia-oxidizing Archaea from soil has been described, additional representatives warrant characterization. We describe an ammonia-oxidizing archaeon (strain MY1) in a highly enriched culture derived from agricultural soil. Fluorescence in situ hybridization microscopy showed that, after 2 years of enrichment, the culture was composed of >90% archaeal cells. Clone libraries of both 16S rRNA and archaeal amoA genes featured a single sequence each. No bacterial amoA genes could be detected by PCR. A [¹³C]bicarbonate assimilation assay showed stoichiometric incorporation of ¹³C into Archaea-specific glycerol dialkyl glycerol tetraethers. Strain MY1 falls phylogenetically within crenarchaeal group I.1a; sequence comparisons to "Candidatus Nitrosopumilus maritimus" revealed 96.9% 16S rRNA and 89.2% amoA gene similarities. Completed growth assays showed strain MY1 to be chemoautotrophic, mesophilic (optimum at 25°C), neutrophilic (optimum at pH 6.5 to 7.0), and nonhalophilic (optimum at 0.2 to 0.4% salinity). Kinetic respirometry assays showed that strain MY1's affinities for ammonia and oxygen were much higher than those of ammonia-oxidizing bacteria (AOB). The yield of the greenhouse gas N₂O in the strain MY1 culture was lower but comparable to that of soil AOB. We propose that this new soil ammonia-oxidizing archaeon be designated "Candidatus Nitrosoarchaeum koreensis."
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http://dx.doi.org/10.1128/AEM.05787-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3233086PMC
December 2011

Development of antibiotic marker-free creeping bentgrass resistance against herbicides.

Acta Biochim Biophys Sin (Shanghai) 2011 Jan;43(1):13-8

Grassland and Forages Division, National Institute of Animal Science, Cheonan, South Korea.

Herbicide-resistant creeping bentgrass plants (Agrostis stolonifera L.) without antibiotic-resistant markers were produced by Agrobacterium-mediated transformation. Embryogenic callus tissues were infected with Agrobacterium tumefaciens EHA105, harboring the bar and the CP4-EPSPS genes for bialaphos and glyphosate resistance. Phosphinothricin-resistant calli and plants were selected. Soil-grown plants were obtained at 14-16 weeks after transformation. Genetic transformation of the selected, regenerated plants was validated by PCR. Southern blot analysis revealed that at least one copy of the transgene was integrated into the genome of the transgenic plants. Transgene expression was confirmed by Northern blot. CP4-EPSPS protein was detected by ELISA. Transgenic plants remained green and healthy when sprayed with Basta, containing 0.5% glufosinate ammonium or glyphosate. The optimized Agrobacterium-mediated transformation method resulted in an average of 9.4% transgenic plants. The results of the present study suggest that the optimized marker-free technique could be used as an effective and reliable method for routine transformation, which may facilitate the development of varieties of new antibiotic-free grass species.
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http://dx.doi.org/10.1093/abbs/gmq106DOI Listing
January 2011

Selective inhibitory potential of silver nanoparticles on the harmful cyanobacterium Microcystis aeruginosa.

Biotechnol Lett 2010 Mar 7;32(3):423-8. Epub 2009 Nov 7.

Department of Environmental Science, Konkuk University, Seoul, 143-701, Korea.

Silver nanoparticles (SNPs) at 1 mg/l inhibited the growth of the toxic cyanobacterium, Microcystis aeruginosa, by 87%. Similar results were obtained in field experiments. M. aeruginosa was more sensitive to SNPs than were green algae. SNPs may be a useful selective biocidal agent for the control of M. aeruginosa.
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http://dx.doi.org/10.1007/s10529-009-0161-8DOI Listing
March 2010

Effect of variation in argon content of calibration gases on determination of atmospheric carbon dioxide.

Talanta 2009 Dec 19;80(2):422-7. Epub 2009 Mar 19.

Center for Gas Analysis, Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, Yuseong-Gu, Daejeon, Republic of Korea.

Carbon dioxide (CO(2)) is a greenhouse gas that makes by far the largest contribution to the global warming of the Earth's atmosphere. For the measurements of atmospheric CO(2) a non-dispersive infrared analyzer (NDIR) and gas chromatography are conventionally being used. We explored whether and to what degree argon content can influence the determination of atmospheric CO(2) using the comparison of CO(2) concentrations between the sample gas mixtures with varying Ar amounts at 0 and 18.6 mmol mol(-1) and the calibration gas mixtures with Ar at 8.4, 9.1, and 9.3 mmol mol(-1). We newly discovered that variation of Ar content in calibration gas mixtures could undermine accuracy for precise and accurate determination of atmospheric CO(2) in background air. The differences in CO(2) concentration due to the variation of Ar content in the calibration gas mixtures were negligible (<+/-0.03 micromol mol(-1)) for NDIR systems whereas they noticeably increased (<+/-1.09 micromol mol(-1)) especially for the modified GC systems to enhance instrumental sensitivity. We found that the thermal mass flow controller is the main source of the differences although such differences appeared only in the presence of a flow restrictor in GC systems. For reliable monitoring of real atmospheric CO(2) samples, one should use calibration gas mixtures that contain Ar content close to the level (9.332 mmol mol(-1)) in the ambient air as possible. Practical guidelines were highlighted relating to selection of appropriate analytical approaches for the accurate and precise measurements of atmospheric CO(2). In addition, theoretical implications from the findings were addressed.
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http://dx.doi.org/10.1016/j.talanta.2009.03.019DOI Listing
December 2009

Production of porphyrin intermediates in Escherichia coli carrying soil metagenomic genes.

FEMS Microbiol Lett 2009 Jun;295(1):42-9

Sustainable Chemical Technologies Division, Korea Research Institute of Chemical Technology, Daejeon, Korea.

Tetrapyrrole pigments are important components of many biological processes, and many of them are produced primarily by microorganisms. We constructed a soil metagenomic library using rice paddy soil consisting of 107 000 fosmid clones with an average DNA insert size of 35 kb. We isolated a clone carrying genes in the porphyrin biosynthetic pathway based on function-driven screening of the library. Through subcloning and mutagenesis analysis, we showed that two genes from soil metagenome, gtrA and hemC, were responsible for pigmentation in Escherichia coli. HPLC and LC-MS analysis of the purified pigments from E. coli carrying pSY143 identified coproporphyrin III without metal as a major compound as well as some other minor porphyrin intermediates. As gtrA and hemC encode glutamyl-tRNA reductase and porphobilinogen deaminase, respectively, which are enzymes involved in the C5 biosynthetic pathway for porphyrin intermediates, our results suggest that hemL, hemB, hemD, and hemE should be provided by the E. coli chromosome to generate a hybrid biosynthetic pathway for production of porphyrin intermediates using E. coli and metagenomic genes.
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http://dx.doi.org/10.1111/j.1574-6968.2009.01577.xDOI Listing
June 2009

Different elution modes and field programming in gravitational field-flow fractionation. Effect of channel angle.

J Chromatogr A 2008 Oct 10;1209(1-2):206-11. Epub 2008 Sep 10.

Department of Chemistry, Hannam University, Daejeon 305-811, South Korea.

Gravitational field-flow fractionation (GrFFF) has been shown to be useful for separation and characterization of various types of micrometer-sized particles. It has been recognized however that GrFFF is less versatile than other members of FFF because the external field (Earth's gravity) in GrFFF is relatively weak and is not tunable (constant), which makes the force acting on the particles constant. A few approaches have been suggested to control the force acting on particles in GrFFF. They include (1) changing the angle between the Earth's gravitational field and the longitudinal axis of the channel, and (2) the use of carrier liquid having different densities. In the hyperlayer mode of GrFFF, the hydrodynamic lift force (HLF) also act on particles. The existence of HLF allows other means of changing the force acting on the particles in GrFFF. They include (1) the flow rate programming, or (2) the use of channels having non-constant cross-section. In this study, with polystyrene latex beads used as model particles, the channel angle was varied to study its effect on elution parameters (such as selectivity, band broadening and resolution) in the steric or in the hyperlayer mode of GrFFF. In addition, the effects of the channel thickness and the flow rate on the elution parameters were also investigated. It was found that, in the steric mode, the resolution decreases as the flow rate increases due to increased zone broadening despite of the increase in the selectivity. At a constant volumetric flow rate, both the zone broadening and the selectivity increase as the channel thickness increases, resulting in the net increase in the resolution. It was also found that the retention time decreases as the channel angle increases in both up- and down-flow positions. The zone broadening tends to increase almost linearly with the channel angle, while no particular trends were found in selectivity. As a result, the resolution decreases as the channel angle increases.
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http://dx.doi.org/10.1016/j.chroma.2008.09.014DOI Listing
October 2008

Enhanced tolerance of transgenic potato plants overexpressing nucleoside diphosphate kinase 2 against multiple environmental stresses.

Transgenic Res 2008 Aug 20;17(4):705-15. Epub 2007 Nov 20.

Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, 52 Eoeun-dong, Yuseong-gu, Daejeon, Korea.

In plants, nucleoside diphosphate kinase 2 (NDPK2) is known to regulate the expression of antioxidant genes. In this study, we developed transgenic potato plants (Solanum tuberosum L. cv. Atlantic) expressing Arabidopsis NDPK2 (AtNDPK2) gene in cytosols under the control of an oxidative stress-inducible SWPA2 promoter (referred to as SN plants) or enhanced CaMV 35S promoter (EN plants) and evaluated their tolerance to various environmental stress, including methyl viologen (MV)-mediated oxidative stress, high temperature, and salt stress. When 250 muM MV was sprayed to whole plants, plants expressing NDPK2 showed significantly an enhanced tolerance compared to non-transgenic (NT) plants. SN plants and EN plants showed 51% and 32% less visible damage than NT plants, respectively. Transcript level of AtNDPK2 gene and NDPK2 activity in SN plants following MV treatment well reflected the plant phenotype. Ascorbate peroxidase (APX) activity was also increased in MV-treated SN plants. In addition, SN plants showed enhanced tolerance to high temperature at 42 degrees C. The photosynthetic activity of SN plants after treatment of high temperature was decreased by about 10% compared to the plants grown at 25 degrees C, whereas that of NT plants declined by 30%. When treated with 80 mM NaCl onto the plantlets, both SN plants and EN plants also showed a significant reduced damage in root growth. These results indicate that overexpression of NDPK2 under the stress-inducible SWPA2 promoter might efficiently regulate the oxidative stress derived from various environmental stresses.
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http://dx.doi.org/10.1007/s11248-007-9155-2DOI Listing
August 2008

Steroidal constituents of rice (Rryza sativa) hulls with algicidal and herbicidal activity against blue-green algae and duckweed.

Phytochem Anal 2007 Mar-Apr;18(2):133-45

Department of Applied Life Science, Konkuk University, Seoul 143-701, South Korea.

Two new compounds, 14-methyl stigmast-9(11)-en-3alpha-ol-3beta-D-glucopyranoside (1) and cholest-11-en-3beta, 6beta, 7alpha, 22beta-tetraol-24-one-3beta-palmitoleate (2), along with the known compound beta-sitosteryl-3beta-D-glucopyranosyl-6'-linoleiate (3), were isolated from the methanolic extract of rice (Oryza sativa) hulls. The structures of the two new compounds were elucidated using one- and two-dimensional NMR in combination with IR, EI/MS, FAB/MS, HR-EI/MS and HR-FAB/MS. In bioassays with blue-green algae, Microcystis aeruginosa UTEX 2388 and duckweed, Lemna paucicostata Hegelm 381, the efficacy of bioactivity of the two new compounds linearly increased as the concentration increased from 0.3 to 300 IgM. Compared with momilactone A, compounds 1 and 2 showed similar and higher inhibitory activities against the growth of M. aeruginosa at a concentration of 300 microM. However, compound 2 was similar to momilactone A in inhibiting L. paucicostata growth at a concentration of 300 microM. As a result, compound 2 appears to have a strong potential for the environmentally friendly control of weed and algae that are harmful to water-logged rice.
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http://dx.doi.org/10.1002/pca.961DOI Listing
May 2007

RETRACTED: Production of transgenic orchardgrass via Agrobacterium-mediated transformation of seed-derived callus tissues.

Plant Sci 2006 Sep 30;171(3):408-14. Epub 2006 May 30.

Major of Dairy Science, Division of Applied Life Science (BK21), Gyeongsang National University, Jinju 660-701, Republic of Korea.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Authors. The editors would like to confirm the retraction of this paper, at the request of the authors, for an unintentional duplication of Figure 2B that was used in a previous publication without attribution, and which did not show the data it claimed to show: S.-H. Lee, D.-G. Lee, H.-S. Woo and B.-H. Lee, Development of transgenic tall fescue plants from mature seed-derived callus via Agrobacterium-mediated transformation. Asian-Austral. J. Anim. Sci., 17 (2004) 1390-1394.
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http://dx.doi.org/10.1016/j.plantsci.2006.05.006DOI Listing
September 2006

Enhanced tolerance of transgenic potato plants expressing both superoxide dismutase and ascorbate peroxidase in chloroplasts against oxidative stress and high temperature.

Plant Cell Rep 2006 Dec 14;25(12):1380-6. Epub 2006 Jul 14.

Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong, Daejeon, 305-806, Korea.

Oxidative stress is a major damaging factor for plants exposed to environmental stresses. In order to develop transgenic potato plants with enhanced tolerance to environmental stress, the genes of both Cu/Zn superoxide dismutase and ascorbate peroxidase were expressed in chloroplasts under the control of an oxidative stress-inducible SWPA2 promoter (referred to as SSA plants). SSA plants showed enhanced tolerance to 250 microM methyl viologen, and visible damage in SSA plants was one-fourth that of non-transgenic (NT) plants that were almost destroyed. In addition, when SSA plants were treated with a high temperature of 42 degrees C for 20 h, the photosynthetic activity of SSA plants decreased by only 6%, whereas that of NT plants decreased by 29%. These results suggest that the manipulation of the antioxidative mechanism of the chloroplasts may be applied in the development of industrial transgenic crop plants with increased tolerance to multiple environmental stresses.
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http://dx.doi.org/10.1007/s00299-006-0199-1DOI Listing
December 2006

Chemical constituents of rice (Oryza sativa) hulls and their herbicidal activity against duckweed (Lemna paucicostata Hegelm 381).

Phytochem Anal 2006 Jan-Feb;17(1):36-45

Department of Applied Life Science, Konkuk University, Seoul 143-701, South Korea.

Four new compounds, stigmastanol-3beta-p-glyceroxydihydrocoumaroate (1), stigmastanol-3beta-p-butanoxydihydrocoumaroate (2), lanast-7,9(11)-dien-3alpha,15alpha-diol-3alpha-D-glucofuranoside (3) and 1-phenyl-2-hydroxy-3,7-dimethyl-11-aldehydic-tetradecane-2-beta-D-glucopyranoside (4), along with several known compounds were isolated from the methanol extract of hulls of Oryza sativa. The new structures were established by one- and two-dimensional NMR and in combination with IR, EI/MS, FAB/MS and HR-FAB/ MS. Compound (3) strongly inhibited the growth of duckweed (Lemna paucicostata Hegelm 381), whilst compounds (2) and (4) exhibited weak inhibition.
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http://dx.doi.org/10.1002/pca.879DOI Listing
March 2006

Complete sequence and organization of the cucumber (Cucumis sativus L. cv. Baekmibaekdadagi) chloroplast genome.

Plant Cell Rep 2006 Apr 9;25(4):334-40. Epub 2005 Dec 9.

Biological Function Research Team, Korea Research Institute of Chemical Technology, P.O Box 107, Yuseong, Daejeon 305-600, Korea.

The nucleotide sequence of the cucumber (Cucumis sativus L. cv. Baekmibaekdadagi) chloroplast genome was completed. The circular double-stranded DNA, consisting of 155,527 bp, contained a pair of inverted repeat regions (IRa and IRb) of 25,187 bp each, which were separated by small and large single copy regions of 86,879 and 18,274 bp, respectively. The presence and relative positions of 113 genes (76 peptide-encoding genes, 30 tRNA genes, four rRNA genes, and three conserved open reading frames) were identified. The major portion (55.76%) of the C. sativus chloroplast genome consisted of gene-coding regions (49.13% protein coding and 6.63% RNA regions; 27.81% LSC, 9.46% SSC and 18.49% IR regions), while intergenic spacers (including 20 introns) made up 44.24%. The overall G-C content of C. sativus chloroplast genome was 36.95%. Sixteen genes contained one intron, while two genes had two introns. The expansion/contraction manner of IR at IRb/LSC and IR/SSC border in Cucumis was similar to that of Lotus and Arabidopsis, and the manner at IRa/LSC was similar to Lotus and Nicotiana. In total, 56 simple sequence repeats (more than 10 bases) were identified in the C. sativus chloroplast genome.
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http://dx.doi.org/10.1007/s00299-005-0097-yDOI Listing
April 2006

EK-2612, a new cyclohexane-1,3-dione possessing selectivity between rice (Oryza sativa) and barnyardgrass (Echinochloa crus-galli).

Pest Manag Sci 2004 Sep;60(9):909-13

Bio-Function Research Team, Korea Research Institute of Chemical Technology, PO Box 107, Taejon 305-606, Korea.

A newly synthesized experimental compound, EK-2612 is one of the class of cyclohexane-1,3-diones which are commonly known to be grasskillers. A greenhouse study was conducted to evaluate the herbicidal performances of EK-2612 on several grass species in comparison with tralkoxydim, a commercialized cyclohexanedione derivative. Like tralkoxydim, the compound EK-2612 showed excellent control efficacy on most grass weeds tested through foliar application rates between 250 and 63 g AI ha(-1). Unlike tralkoxydim, however, EK-2612 showed a good rice safety, and there was no rice damage observed at the level below 125 g AI ha(-1), while rice injury developed at the same application rates of tralkoxydim. With this rice safety, EK-2612 controlled barnyardgrass effectively up to the two-leaf stage under both submerged and dried paddy conditions. An in vitro ACCase assay indicated that EK-2612 is a strong ACCase inhibitor; however, the dose-response was not substantially different in rice and barnryardgrass, showing I50 values of 0.1 and 0.12 microM, respectively. These results suggest that the compound EK-2612 is targeting plant ACCase, but the whole-plant rice safety is not attributable to a different inhibition of the target site in rice from that in barnyardgrass.
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http://dx.doi.org/10.1002/ps.868DOI Listing
September 2004

Screening extracts of Achyranthes japonica and Rumex crispus for activity against various plant pathogenic fungi and control of powdery mildew.

Pest Manag Sci 2004 Aug;60(8):803-8

Biological Function Research Team, Korea Research Institute of Chemical Technology, Yusong-Gu, Taejon, Korea.

Methanol extracts of fresh materials of 183 plants were screened for in vivo antifungal activity against Magnaporthe grisea, Corticium sasaki, Botrytis cinerea, Phytophthora infestans, Puccinia recondita and Erysiphe graminis f sp hordei. Among them, 33 plant extracts showed disease-control efficacy of more than 90% against at least one of six plant diseases. The methanol extracts of Achyranthes japonica (whole plant) and Rumex crispus (roots) at concentrations greater than 11 g fresh weight of plant tissue per litre of aqueous Tween 20 solution effectively controlled the development of barley powdery mildew caused by E graminis f sp hordei in an in vivo assay using plant seedlings. At a concentration of 300 g fresh weight of plant tissue per litre of Tween 20 solution, the two extracts were as efficient as the fungicide fenarimol (30 mg litre(-1)) and more active than the fungicide polyoxin B (100 and 33 mg litre(-1)) against Sphaerotheca fuliginea on cucumber plants in glasshouse trials.
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http://dx.doi.org/10.1002/ps.811DOI Listing
August 2004