• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.40-44
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• 2003

Soil-borne infectious disease including Pythium aphanidermatum and Rhizoctonia solani causes severe damage to plants, such as cucumber. This soil-borne infectious disease was not controlled effectively by chemical pesticide. Since these diseases spread through the soil, chemical agents are usually ineffective. Instead, biological control, including antagonistic microbe can be used as a preferred control method. An efficient method was developed to select an antagonistic strain to be used as a biological control agent strain. In this new method, surface tension reduction potential of an isolate was included in the ‘decision factor’ in addition to the other factors, such as growth rate, and pathogen inhibition rate. Considering these 3 decision factors by a statistical method, an isolate from soil was selected and was identified as Bacillus sp. GB16. In the pot test, this strain showed the best performance among the isolated strains. The lowest disease incidence rate and fastest seed growth was observed when Bacillus sp. GB16 was used. Therefore this strain was considered as plant growth promoting rhizobacteria (PGPR). The action of surface tension reducing component was deduced as the enhancement of wetting, spreading, and residing of antagonistic strain in the rhizosphere. This result showed that new selection method was significantly effective in selecting the best antagonistic strain for biological control of soil-borne infectious plant pathogen. The antifungal substances against P. aphanidermatum and R. solani were partially purified from the culture filtrates of Bacillus sp. GB16. In this study, lipopeptide possessing antifungal activity was isolated from Bacillus sp. GB16 cultures by various purification procedures and was identified as a surfactin-like lipopeptide based on the Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), high performance liquid chromatography mass spectroscopy (HPLC-MS), and quadrupole time-of-flight (Q-TOF) ESI-MS/MS data. The lipopeptide, named GB16-BS, completely inhibited the growth of Pythium aphanidermatum, Rhizoctonia solani, Penicillium sp., and Botrytis cineria at concentrations of 10 and 50 mg/L, respectively. A novel method to prevent the foaming and to provide oxygen was developed. During the production of surface active agent, such as lipopeptide (surfactin), large amount of foam was produced by aeration. This resulted in the carryover of cells to the outside of the fermentor, which leads to the significant loss of cells. Instead of using cell-toxic antifoaming agents, low amount of hydrogen peroxide was added. Catalase produced by cells converted hydrogen peroxide into oxygen and water. Also addition of corn oil as an oxygen vector as well as antifoaming agent was attempted. In addition, Ca-stearate, a metal soap, was added to enhance the antifoam activity of com oil. These methods could prevent the foaming significantly and maintained high dissolved oxygen in spite of lower aeration and agitation. Using these methods, high cell density, could be achieved with increased lipopeptide productivity. In conclusion to produce an effective biological control agent for soil-borne infectious disease, following strategies were attempted i) effective screening of antagonist by including surface tension as an important decision factor ii) identification of antifungal compound produced from the isolated strain iii) novel oxygenation by $H_2O_2-catalase$ with vegetable oil for antifungal lipopeptide production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1668-1675
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• 2004

The effect of pH on surface hydrophobicity, sulfhydryl group, infrared spectrum, SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) pattern and enthalpy was investigated in recovered protein from mackerel and frozen blackspotted croaker by alkaline processing. Hydrophobic residue in myofibrillar protein exposed to the surface of protein, and hydrophobic interaction were the highest around 6$0^{\circ}C$. The surface hydrophobicity was different between myofibrillar protein and myofibrillar protein including sarcoplasmic protein (recovered protein). The peak at 1636 c $m^{-l}$ was increased with pH, and the recovered protein was unfolded in alkali pH. Difference of surface and total sulfhydryl group at pH 7.0 and 10 was comparative high, and decrease of surface sulfhydryl group indicated formation of S-S bonds. Mackerel and frozen blackspotted croaker in alkaline pH showed bands of polymerized myosin heavy chain on SDS-PAGE pattern. The transition temperatures of recovered protein were 33.1, 44.3 and 65.5$^{\circ}C$. Gelation of recovered protein from alkali processing was estimated by increase of $\beta$-sheet structure by pH treatment, S-S bonds by oxidation of surface sulfhydryl group in heating, polymerization of myosin heavy chain in order.r.

• The Journal of Korean Medicine
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• v.33 no.1
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• pp.42-51
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• 2012

Objectives: We measured the density of smoke and harmful gases emitted from burning adhesive indirect moxa. Through the test we aimed to find out if there was an excessive amount of smoke emitted and if it included harmful gases. Methods: 9 types of adhesive indirect moxa were chosen. The buffer layers which do not burn during treatment were removed and 10g of each moxa were made into powder and put into a holder. A smoke density chamber (Smoke Density Chamber FTT. U.K) and Fourier transform infrared spectroscopy (FT-IR I 4001. MIDAC U.S.A.) were used to measure the density of smoke and harmful gases emitted from burning moxa by ISO 5659-2 test. Results: The result of measuring maximum smoke density showed that the regular indirect adhesive moxa (A-F) emitted high density smoke of 172.1-291.4Ds. The smokeless moxas, Seoam moxas, emitted the least amount of 3.4-5.5Ds. Concentrations of 7 typical harmful gases (CO, HCl, HCN, HBr, HF, SO2, NOx) were measured and all of the moxas emitted CO due to incomplete combustion. 4 types of moxa emitted NOx and all smokless moxas emitted NOx. HBr, HCN, HCl, HF, SO2 were not found in any of the moxas. Conclusions: The amount of harmful gases emitted from burning moxa was much lower than short-term exposure standards of chemical and physical factors (Ministry of Labor 2010-44). Further experiments measuring gases from moxa combustion should be done in larger environments similar to normal medical clinics.

• Journal of Broadcast Engineering
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• v.21 no.6
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• pp.957-964
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• 2016

Acquisition of reliable depth maps is a critical requirement in many applications such as 3D videos and free-viewpoint TV. Depth information can be obtained from the object directly using physical sensors, such as infrared ray (IR) sensors. Recently, Time-of-Flight (ToF) range camera including KINECT depth camera became popular alternatives for dense depth sensing. Although ToF cameras can capture depth information for object in real time, but are noisy and subject to low resolutions. Recently, filter-based depth up-sampling algorithms such as joint bilateral upsampling (JBU) and noise-aware filter for depth up-sampling (NAFDU) have been proposed to get high quality depth information. However, these methods often lead to texture copying in the upsampled depth map. To overcome this limitation, we formulate a convex optimization problem using higher order regularization for depth map upsampling. We decrease the texture copying problem of the upsampled depth map by using edge weighting term that chosen by the edge information. Experimental results have shown that our scheme produced more reliable depth maps compared with previous methods.

• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.242-247
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• 1998

Hydrogenated amorphous carbon nitride[a-C:H(N)] films were deposited on p-type Si(100) at room temperature with bias voltage of 200 V by DC saddle-field plasma-enhanced chemical vapor deposition. Effects of the ratio of $N_2$ to $CH_4$($N_2/CH_4$), in the range of 0 and 4 on such properties as optical properties, microstucture, relative fraction of nitrogen and carbon, etc. of the films have been investigated. The thickness of the a-C:H(N) film was abruptly decreased with the addition of nitrogen, but at $N_2/CH_4$>0.5, the thickness of the film gradually decreased with the increase of the $N_2/CH_4$. The ratio of N to C(N/C) of the films was saturated at 0.25 with the increase of $N_2CH_4$. N-H, C≡N bonds of the films increased but C-H bond decreased with the increase of $N_2CH_4$.Optical band gap energy of the film decreased from 2.53 eV at the ratio of $N_2CH_4$=4.

• Journal of Pharmaceutical Investigation
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• v.26 no.2
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• pp.71-82
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• 1996

This study has been undertaken to evaluate hydrophobic cyclodextrin(CD) derivatives as a sustained release carrier of azidothymidine(AZT), AZT, which has potent activity against AIDS and AIDS-related complex as thymidine analogue, has been reported that it has significant toxicity and short half life. Therefore, it is necessary to design sustained release oral dosage form to avoid undesirable side effects attributable to an excessive plasma concentration and to reduce the frequency of administration of AZT. Inclusion complexes of AZT with $acetyl-{\beta}-cyclodextrin\;(AC{\beta}CD)$ and $triacetyl-{\beta}-cyclodextrin(TA{\beta}CD)$ were prepared by solvent evaporation method. Interactions of AZT with CD were investigated by Differential Scanning Calorimetry(DSC) and Infrared Spectrophotometry(IR). The decreasing order of water solubilities of AZT and AZT-CD inclusion complexes were as follows; $AZT\;(27.873{\pm}0.015,mg/ml)\;>\;AZT-AC{\beta}CD\;(3.377{\pm}0.003)\;>\;AZT-TA{\beta}CD\;(2.528{\pm}0.001)$. Partition coefficients of $AZT-AC{\beta}CD\;and;\AZT-TA{\beta}CD$ inclusion complexes were increased by 1.27-fold, 1.54-fold in pH 1.2 and 1.32-fold, 1.47-fold in pH 6.8 in comparison with that of AZT. The mean dissolution time (MDT, min) which represents the rapidity of dissolution rate of AZT, $AZT-AC{\beta}CD,\;AZT-TA{\beta}CD$ were 5.12, 14.02 and 19.38 min in pH 1.2 and 2.52, 15.19 and 18.19 min in pH 6.8. AZT was very rapidly and completely dissolved in pH 1.2 and pH 6.8 within 5 minutes. But AZT-CD inclusion complexes showed the sustained release pattern in comparison with AZT alone. The simultaneous in situ nasal and jejunal recirculation study to compare the intrinsic absorptivity and the property of absorption sites revealed that the absorption of $AZT-TA{\beta}CD\;(N:35.35{\pm}1.08%,\;J:27.47{\pm}1.18%)$ was more than that of $AZT\;(N:16.89{\pm}2.25%,\;J:15.86{\pm}2.33%)$. The above results suggest that $TA{\beta}CD$ which is a hydrophobic cyclodextrin may serve as sustained release carrier with absorption enhancing effect.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.1-6
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• 2011

${\gamma}$-PGA(poly-${\gamma}$-glutamic acid) is an unusual anionic polypeptide that is made of D- and L-glutamic acid units connected by amide linkages between ${\alpha}$-amino and ${\gamma}$-carboxylic acid groups. ${\gamma}$-PGA has been isolated from many kinds of organisms. Many Bacillus strains produce ${\gamma}$-PGA as a capsular material of an extracellular viscous material. It is safe for eating as a viscosity element of fermented soybean products such as Chungkookjang and Natto. It is biodegradable, edible and nontoxic toward humans and the environment and its molecular weight varies from ten thousand to several hundred thousand depending on the kinds of strains used. Therefore, potential applications of ${\gamma}$-PGA and its derivatives have been of interest in the past few years in a broad range of industrial fields such as food, cosmetics, medicine, water-treatment, etc. In this study, a bacterium, Bacillus subtilis GS-2 isolated from the Korean traditional seasoning food, Chungkookjang could produce a large amount of ${\gamma}$-PGA with high productivity and had a simple nutrient requirement. Based on carbon utilization pattern and partial 16S rRNA sequence analysis, the GS-2 strain was identified as B. subtilis. The determination of purified ${\gamma}$-PGA was confirmed with thin layer chromatography (TLC), high performance liquid chromatography (HPLC), fourier transform infrared (FT-IR) spectra, and $^1H$-nuclear magnetic resonance ($^1H$-NMR) spectroscopy.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.63-66
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• 2011

The bark of Machilus thunbergii was extracted with 80% aqueous methanol (MeOH), and the concentrated extract was partitioned using ethyl acetate (EtOAc), butanol (n-BuOH), and $H_2O$, successively. From the EtOAc fraction, five lignans were isolated through the repeated silica gel, octadecyl silica gel (ODS) and, Sephadex LH-20 column chromatography. Based on nuclear magnetic resonance (NMR), mass spectroscopy (MS), and infrared spectroscopy (IR) spectroscopic data, the chemical structures of the compounds were determined to be machilin A (1), machilin F (2), licarin A (3), nectandrin A (4), and nectandrin B, (5). This study presents comparative account of five lignans from M. thunbergii bark contributing inhibition of low density lipoprotein (LDL), ACAT-1, and ACAT-2. Compounds 2-5 showed varied degree of antioxidant activity on LDL with $IC_{50}$ values of 2.1, 11.8, 15.3, and $4.1{\mu}M$. Compounds 1, 2, and 3 showed inhibition activity on ACAT-1 with values $63.4{\pm}6.9%$ ($IC_{50}=66.8{\mu}M$), $53.7{\pm}0.9%$ ($IC_{50}=109.2{\mu}M$), and $78.7{\pm}0.2%$ ($IC_{50}=40.6{\mu}M$), respectively, at a concentration of 50 mg/mL, and on ACAT-2 with values $47.3{\pm}1.5%$ ($IC_{50}=149.7{\mu}M$), $39.2{\pm}0.2%$ ($IC_{50}=165.2{\mu}M$), and $52.1{\pm}1.0%$ ($IC_{50}=131.0{\mu}M$, respectively, at a concentration of 50 mg/mL.

• Microbiology and Biotechnology Letters
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• v.46 no.2
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• pp.120-126
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• 2018

As a basic study for environment-friendly production of bacterial cellulose (BC) dressing with antimicrobial activity, we isolated and identified acetic acid bacteria which are resistant to silver ions and can biosynthesize silver nanoparticles. Furthermore, conditions of BC production by selected strain were also investigated. Strain G7 isolated from decayed grape skin was able to grow in the presence of 0.1 mM $AgNO_3$ which was identified as Acetobacter intermedius based on 16S rRNA gene analysis. BC production was the highest in a medium containing 2% glucose as a carbon source, 2% yeast extract as a nitrogen source, and 0.115% acetic acid as a cosubstrate. Structural properties of BC produced in optimal medium were studied using Fourier-transform infrared spectroscopy and X-ray diffractometer, and it was found that BC produced was cellulose type I that was the same as a typical native cellulose. When strain G7 was cultured in an optimal medium containing 0.1 mM $AgNO_3$, the color of the culture broth turned into reddish brown, indicating that silver nanoparticles were formed. As a result of UV-Vis spectral analysis of the culture, it was found that a unique absorption spectrum of silver nanoparticles at 425 nm was also observed. Scanning electron microscopic observations showed that silver nanoparticles were formed on the surface and pores of BC membrane.

• Journal of the Mineralogical Society of Korea
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• v.20 no.3
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• pp.223-229
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• 2007

The mechanism of hydrothermally synthesizing Na-A zeolite from siliceous mudstone at a $Na_2O/SiO_2$ ratio of 0.6, a $SiO_2/Al_2O_3$ 2.0 and a $H_2O/Na_2O$ 119 has been observed by IR, DTA, XRD and SEM. This mudstone is a tertiary periodic sedimentary rock and widely spreads around the Pohang area. In the early hydrothermal synthesis at $80^{\circ}C$ in an autoclave, sodium silicate and sodium aluminate were found to be preferentially reacted to generate Na-A type zeolite. Gibbsite and bayerite were also formed due to the presence of extra aluminum oxide in the feedstock. As reaction time in-creased up to 50 h, residual sodium aluminatewas reacted with siliceous mudstone, causing the Na-A zeolite crystal to grow and the hydroxylsodalite to generate. Therefore, in the $14{\sim}50\;h$ synthetic time, Na-A zeolite and hydroxylsodalite were formed. Also, if reaction time passed over 50 h, a part of the Na-A zeolite was finally redissolved and reacted with hydroxylsodalite to synthesize Na-P zeolite, generating porous surface of Na-A zeolite and disappearing hydroxylsodalite.