• Journal of the Korean GEO-environmental Society
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• v.17 no.1
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• pp.13-19
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• 2016

Soft ground stabilization is needed to construct large civil facilities on the soft clay ground. Pre-loading method, which is accelerating consolidation method, is generally used to stabilize the soft ground. However, pre-loading method is required long construction period and quantities of fill material. Therefore, electro-osmosis method is used to replace pre-loading method for stabilizing the soft ground. Electro-osmosis method is disadvantageous in constructive and economic aspects because it is needed a metallic electrode. So, in order to solve the those disadvantages, plastic electrode was developed to replace metallic electrode. Plastic electrode, which is made by using nano-technology on existing Plastic Drain Board (PDB), was used to supply the electric power. In this study, therefore, the model test was conducted to confirm the effect of improvement and electrical characteristics of soft ground by spacing of plastic electrode. The result shows that the effect of improvement of soft ground was decreased up to 45% by increasing electrode spacing and electrical characteristics on the soft ground were influenced by consolidation settlement with electrode spacing.

• The Korean Journal of Mycology
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• v.46 no.2
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• pp.145-160
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• 2018

Members of Chlorociboria are soft-rot ascomycetes that produce blue-green pigment. We investigated the growth characteristics of two Korean species of Chlorociboria, eight strains of Chlorociboria aeruginascens and Chlorociboria poutoensis, under various culture conditions (solid media, temperature, pH) and screened them for extracellular enzyme activity. Although the growth rate was slow, all tested strains of Chlorociboria spp. grew well on potato dextrose agar (PDA; 16.3~42.6 mm after 60 days) or Sabouraud dextrose agar (SDA), but not on malt extract agar (MEA). Compared with C. aeruginascens strains, C. poutoensis strains exhibited higher expression of blue-green pigments on both PDA and SDA media. The optimal temperature for mycelial growth was $20{\sim}25^{\circ}C$, and mycelial growth was lower at $30^{\circ}C$ than at $10^{\circ}C$. All strains tended to have increased mycelial growth as the incubation temperature increased in the range of 10 to $20^{\circ}C$. The optimal pH of potato dextrose broth (PDB) for mycelial growth varied according to the strain under static culture conditions. Maximum biomass production was obtained at pH 6.0 for NIFoS 579 ($114.3{\pm}5.1mg/60days$), but it maintained a stable pigment expression under a broad pH spectrum. The activities of both cellulase and laccase were observed in all tested strains of Chlorociboria spp. Enzyme activities of NIFoS 579 were remarkably higher than those of the other strains. From these results, we suggest that C. poutoensis NIFoS 579 is a potential candidate for use as a source of natural blue-green dye.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.333-344
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• 2018

Selection of the optimal culture medium and evaluation of the antimicrobial activity against various phytopathogens were performed for four entomopathogenic fungal isolates with excellent insecticidal and antimicrobial activity against the two-spotted spider mite (Tetranychus urticae), green peach aphid (Myzus persicae), and gray mold (Botrytis cinerea). The optimal medium was selected by measuring the amount of blastospore production and the antifungal activity of the culture medium. On the basis of these experiments, GY medium was selected for Beauveria bassiana 2R-3-3-1 and Metarhizium anisopliae 4-2, SD3, and PDB medium for B. bassiana SD15. The antimicrobial activity test against other phytopathogens indicated that all four isolates showed high antifungal activities against Colletotrichum acutatum and Sclerotinia sclerotiorum. However, for Phytophthora capsici and C. fructicola, only M. anisopliae SD3 showed a high antifungal activity against P. capsici, and the other three isolates had little activity. Antibacterial activity against Clavibacter michiganensis subsp. michiganensis was high in two isolates of M. anisopliae but not in two isolates of B. bassiana. Thus, it was confirmed that entomopathogenic fungi effective for pest control could be effectively used as a control agent for various plant diseases.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.17-23
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• 2002

In order to investigate effects if loess on the mycellial pellet formation a phosphate-solubilizing fungus. Aspergillus sp. PS-104 was cultured in potato dextrose broth containing loess. The strain formed an amorphous pellet or loose aggregates agitated at a low speed (50 rpm) while spherical and regular pellets at a high speed (150 rpm) The higher concentration of loess was added, the smaller size of a pellet was formed during the submerged culture of the strain. As shown in results, being cultured in the PDB medium supplemented with 1.0% loess the pellet size was maximally reduced to a fourth compared to the control. Evaluating the addition effect of several components of loess such as $SiO_2$, $Fe_2O_3$, $Al_2O_3$, $CaCO_3$, $CaSO_4$ and $MgCO_3$ on the reduction of mycellial pellet size the higher concentration was supplied, the smaller size of pellet was formed except $Al_2O_3$. And the smallest pellet size was recorded at the concentration of 1.0% (W/V) magnesium carbonate.

• KSBB Journal
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• v.27 no.5
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• pp.301-307
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• 2012

The hyphal growth, production of color pigments and monacolin K by Monascus strains were investigated in liquid medium. Thirty five different strains were collected and cultured in potato dextrose yeast extract broth (PDYB), potato dextrose broth (PDB) and malt extract broth (MEB) medea at $25^{\circ}C$ for 7 days. The growth rates of most of strains were highest in PDYB medium. Growth rate as well as pigment production were influenced by suspension conditions of mycelia during liquid cultivation. Most of strains producing monacolin K corresponded to strains producing red pigment highly and showing more pH changes of liquid media. Monacolin K produced from strains was detected in culture broth as well as mycelia. Any citrinin was not detected in monacolin K producing strains. These results imply that the selection of the strains producing red pigment highly and showing more pH changes in liquid cultivation could be applied for primary screening of Monascus strains for preparation of red mold rice.

• Journal of Applied Biological Chemistry
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• v.53 no.4
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• pp.225-231
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• 2010

To understand the inhibitory activity with changing hydroxyl substituents ($R_l-R_9$) of polyhydroxy substituted 2-phenyl-l,4-benzopyrone analogues (1-25) against tyrosinase (PDB ID: oxy-form; 1WX2), molecular docking and the three dimensional quantitative structure-activity relationships (3D-QSARs: Comparative molecular field analysis (CoMFA) & Comparative molecular similarity indices analysis (CoMSIA)) were studied quantitatively. The statistically best models were CoMFA 1 and CoMSIA 1 model from the results. The optimized CoMSIA 1 model with the sensitivity of the perturbation and the prediction produced ($dq^2'/dr_{yy'}^2$=1.009 & $q^2$=0.51l) by a progressive scrambling analysis were not dependent on chance correlation. The inhibitory activities with optimized CoMSIA 1 model were dependent upon electrostatic factor (51.4%) of substrate molecules. Contour mapping the 3D-QSAR models to the active site of tyrosinase provides new insight into the interaction between tyrosinase as receptor and 2-phenyl-l,4-benzopyrone analogues as inhibitor. Therefore, the results will he able to apply to the optimization of a new potent tyrosinase inhibitors.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.437-443
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• 2016

In this study Streptomyces strains were isolated from soils and their antifungal activities and involved mechanisms were investigated. Among over 400 isolates of actinomycetes, Streptomyces costaricanus HR391 was selected as a potential antagonist to control several plant-pathogenic fungi. S. costaricanus HR391 inhibited mycelial growth of Fusarium oxysporum f. sp. raphani, F. oxysporum f. sp. niveum, F. oxysporum f. sp. lycopersici, and Rhizoctonia solani by 26.5, 26.2, 21.2, and 23.8%, respectively compared to those of uninoculated control after 7-day incubation on PDB medium. S. costaricanus HR391 produced $89{\mu}M$ of siderphore, and showed fungal cell wall-degrading activity including $0.46{\mu}mol/min/mg$ of chitinase and $0.83{\mu}mol/min/mg$ of ${\beta}$-1,3 glucanase. S. costaricanus HR391 secreted 87.49 mg/L of rhamnolipid, and produced 9.49 mg/L and 4.3 mM of lipopeptide, iturin A and surfactin, respectively, all they are membrane-disrupting biosurfactants. It also produced antimicrobial peptide and antibiotics phenazine. In addition to antifungal substances, S. costaricanus HR391 secreted plant growth-promoting phytohormones, zeatin, gibberellins and IAA. These results suggest that S. costaricanus HR391 may be utilized as an environment-friendly biocontrol agent against some important pathogenic fungi.

• Journal of agriculture & life science
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• v.46 no.4
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• pp.9-20
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• 2012

Eugenol is a volatile compound synthesized by eugenol synthase in various plants and belongs to phenylpropene compounds. However, characteristics of eugenol synthase in tomato has not been known. Therefore, we cloned a full length cDNA of a putative eugenol synthase from tomato 'Micro-Tom' using rapid amplification of cDNA ends (RACE) technique and named a clone SlEGS. Open reading frame of SlEGS was 921bp long and its deduced amino acid sequence was 307bp. The BLAST analysis indicated that SlEGS shared high similarity with PhEGS1 (67.1%) and CbEGS2 (69.4%). Amino acid composition of SlEGS was determined by CLC genomics workbench tool and 3D structure of SlEGS was constructed by homology modeling using Swiss-PDB viewer and validated using PROCHECK and ProSA-web tool. In addition, the physiochemical properties of SlEGS was evaluated using ExPASy's ProtParam tool. Molecular weight was 33.93kDa and isoelectric point was 5.85 showing acidic nature. Other properties such as extinction coefficient, instability index, aliphatic index, and grand average hydropathy was also analyzed.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.48-54
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• 2008

A putative ${\omega}$-aminotransferase gene, cc3143 (aptA), from Caulobacter crescentus was screened by bioinformatical tools and overexpressed in E. coli, and the substrate specificity of the ${\omega}$-aminotransferase was investigated. AptA showed high activity for short-chain ${\beta}$-amino acids. It showed the highest activity for 3-amino-n-butyric acid. It showed higher activity toward aromatic amines than aliphatic amines. The 3D model of the ${\omega}$-aminotransferase was constructed by homology modeling using a dialkylglycine decarboxylase (PDB ID: 1DGE) as a template. Then, the ${\omega}$-aminotransferase was rationally redesigned to increase the activity for 3-amino-3-phenylpropionic acid. The mutants N285A and V227G increased the relative activity for 3-amino-3-phenylpropionic acid to 3-amino-n-butyric acid by 11-fold and 3-fold, respectively, over that of wild type.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.1
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• pp.25-33
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• 2005

Recently a cDNA clone of apoLp-III from Hyphantria cunea was isolated and subjected to computational analysis to compare with other available sequences. Multiple sequence alignments were carried out using the amino acid sequences of apoLp-III from six insects. It was found that the H. cunea apoLp-III has relatively high sequence identities to Spodoptera litura ($69.5\%$), Manduca sexta ($66.8\%$), Galleria mellonella ($65.1\%$), Bombyx mori N4 ($54.3\%$) but less identity to Locusta migratoria ($18.3\%$). The amino acid composition was compared with other insects using EXPASY tools; it shows that alanine (Ala), glutamine (Gln), leucine (Leu) and lysine (Lys) are the major amino acid components of apoLp-III in H. cunea as well as other lepidopterans. Homology modeling performed using PSI-BLAST (PDB template M. sexta) reveals that the apoLp-III molecules consist of five, long amphipathic alpha helical bundles with short loops connecting the helices and shows homology with other insects. Phylogenetic analysis shows that the orthopteran apoLp-III represented by locust was most distantly related to the lepidopteran insects.