• Development and Reproduction
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• v.20 no.1
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• pp.63-71
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• 2016

Human embryonic stem cells (hESCs) have been routinely cultured on mouse embryonic fibroblast feeder layers with a medium containing animal materials. For clinical application of hESCs, animal-derived products from the animal feeder cells, animal substrates such as gelatin or Matrigel and animal serum are strictly to be eliminated in the culture system. In this study, we performed that SNUhES32 and H1 were cultured on human amniotic fluid cells (hAFCs) with KO-SR XenoFree and a humanized substrate. All of hESCs were relatively well propagated on hAFCs feeders with xeno-free conditions and they expressed pluripotent stem cell markers, alkaline phosphatase, SSEA-4, TRA1-60, TRA1-81, Oct-4, and Nanog like hESCs cultured on STO or human foreskin fibroblast feeders. In addition, we observed the expression of nonhuman N-glycolylneuraminic acid (Neu5GC) molecules by flow cytometry, which was xenotransplantation components of contamination in hESCs cultured on animal feeder conditions, was not detected in this xeno-free condition. In conclusion, SNUhES32 and H1 could be maintained on hAFCs for humanized culture conditions, therefore, we suggested that new xeno-free conditions for clinical grade hESCs culture will be useful data in future clinical studies.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.228-234
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• 2006

The culture conditions were investigated to maximize the production of laccase from Fomitella fraxinea mycelia. Among the tested media, mushroom complete medium (MCM) showed the highest production of the enzyme. The optimum culture medium was 2% dextrose, 0.4% $(NH_4)_{2}HPO_4$, 0.05% $Na_{2}HPO_{4}{\cdot}7H_{2}O$, and 0.05% KCl as carbon, nitrogen, phosphorus, and inorganic salt sources respectively. SDS-PAGE followed by laccase activity staining using 2,6-djmethoxyphenol as the substrate was performed to identify the laccase activity under culture conditions studied. Zymogram analysis of the culture supernatant showed a laccase band with a molecular mass of 50 kDa. The enzyme production from F. fraxinea was reached to the highest level after the cultivation for 10 days at $25^{\circ}C$ and initial pH 8. The enzyme activity of the culture supernatant was most active at $50^{\circ}C$ and pH 5.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.114-121
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• 2010

Oxygen sensitivity and substrate requirement have been known as possible reasons for the intricate growth of Dehalococcoides spp. and limiting factors of for routinely applying bioaugmentation using anaerobic Dehalococcoides-containing microbes for remediating chlorinated organic compounds. To explore the effect of the short-term exposure of the short-term exposure of oxygen on Dehalococcoides capability, dechlorination performance, and hydrogen production fermentation from formate, an anaerobic reductive dechlorination mixed-culture (Evanite culture) including dehalococcoides spp. was in this study. In the results, once the mixed-culture were exposed to oxygen, trichloroethylene (TCE) degradation rate decreased and it was not fully recovered even addition of excess formate for 40 days. In contrast, hydrogen was continuously produced by hydrogen-fermentation process even under oxygen presence. The results indicate that although the oxygen-exposed cells cannot completely dechlorinate TCE to ethylene (ETH), hydrogen fermentation process was not affected by oxygen presence. These results suggest that dechlorinating microbes may more sensitive to oxygen than fermenting microbes, and monitoring dechlorinators activity may be critical to achieve an successful remediation of a TCE contaminated-aquifer through bioaugmentation using Dehalococcoides spp..

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.5
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• pp.269-274
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• 2002

A large number of factors such as osteotropic hormones, cytokines, or growth factors are related to the bone remodeling which is characterized by the coupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation. Recent investigations have indicated that cytokines such as $interleukin-1{\beta}\;(IL-1{\beta})$ and tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ play a potential role in the bone resorption associated with a variety of pathological conditions such as inflammatory osteolytic disease. Collagen is the most abundant protein of the extracellular matrix of bone, and the participation of collagenase in bone resorption has been widely investigated. In this study, effects of $IL-1{\beta}$ and $TNF-{\alpha}$ on the release of collagenase from osteoblastic cells were measured. The gelatinase activity was also measured by gel substrate analysis (zymography) after electrophoresis of conditioned media of osteoblastic cell culture. $IL-1{\beta}$ increased the collagenase activity in ROS17/2.8 and HOS cell culture. $TNF-{\alpha}$ also increased the collagenase activity of osteoblastic cells. When two kinds of cytokines were treated simultaneously in the culture of osteoblastic cells, synergistic increase of collagenase activity was seen in ROS17/2.8 cells. $IL-1{\beta}$ and $TNF-{\alpha}$ significantly increased the collagenase activity after 6 hour treatment in the osteoblastic cell culture, and there was no additional increase according to the culture period. Osteoblastic cells released the gelatinase and molecular weight of this enzyme was measured about 70 KDa as assessed by zymogram. $IL-1{\beta}$ and $TNF-{\alpha}$ showed increase of the gelatinase activity produced by ROS17/2.8 and HOS cells. Taken together, this study suggested that $IL-1{\beta}$ and $TNF-{\alpha}$ can modulate bone metabolism, at least in part, by increased release of collagenase and gelatinase from osteoblasts.

• Journal of agriculture & life science
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• v.44 no.5
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• pp.9-13
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• 2010

This study was conducted to identify the possibility of utilization of coconut substrates for nutrition culture of cut-chrysanthemum. The materials of substrate were composed of dust, fiber, and chip from coco-nut fruit. Dust was used in dust (100%), and dust+chip and +fiber were used in the ratio of 7:3 (v:v), respectively, as coconut mixture substrate. Perlite was used as control in this experiment. Water content in the perlite medium was lower than in dust substrate. The pH of all coconut substrates ranged from 6.5 to 5.8, whereas perlite substrate ranged from 7.3 to 6.7. While, EC of dust substrates shown to be highest but perlite substrate was lowest. The growth of chrysanthemum such as stem length, leaf area, and dry matter showed better results in coconut substrates than that of perlite and dust. However, there was no differences days to in flowering among treatments.

• Journal of Mushroom
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• v.16 no.4
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• pp.257-262
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• 2018

The aim of this study was to re-use spent mushroom substrate (SMS) with increased total nitrogen (T-N) and amino acid content and reduce the amount of cottonseed meal used as nutrient supplement in Pleurotus ostreatus cultivation. Bacteria used for improvement of the T-N content were GM20-4(Bacillus sp.) and Rhodobacter sphaeroides (RS). GM20-4 was isolated from the SMS of P. ostreatus and RS was obtained from Gwangjusi agricultural technology center. SMS in T1, T2, and T3 was reused as substrate after drying and the T-N content of dried SMS (D-SMS) was increased by 0.34% by treatment with the bacteria. T1 with 8% D-SMS and T2 with 18% D-SMS had higher rates of primordia formation compared with T3 and the control. The biological efficiency of the control and of treatment with 8%, 18%, and 26% D-SMS was 110%, 114%, 112%, and 79%, respectively. Considering the economic cost, yield, and biological efficiency, T2 with 18% D-SMS as the culture substrate for P. ostreatus was shown to be the most effective for cultivation.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.130-135
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• 2010

To select the viable alternative substrates among the variable organic substrates for productivity enhancement and production cost-reduction of oyster mushroom in bottle culture, this study was carried out at mushroom research institute of GGRDA in 2007. In bottle culture of oyster mushroom (Plerutus ostreatus), the seedcakes of rape (RS), soybean (SS), coconut (CCS), and kapok (KS) were examined as substitute of cotton seedcake which was primary nutritive material of mushroom growing substrate. The chemical properties of substrate mixed with kapok seedcake is similar to the mixture with cotton seedcake in T-C, T-N, C/N ratio, and other nutrients. Mixed growing substrate containing cotton seedcake and kapok seedcake was superior to other mixtures 99.2% and 99.5%, respectively in spawning ratio and was faster mycellium growth in column test than that of soybeen seedcake, cotton + soybeen seedcake, and coconut seedcake. The period required in first pin-heading was 1-2 days longer in rape and soybeen seedcake mixture. Also there wad no primodia and fruitbody formation at soybeen seedcake mixture which had highest T-N content among the other mixed substrates. Yield per bottle and biological efficiency were highest of 144.6 g and 75.4%, respectively at kapok seedcake mixture. As a result, this study found that cotton seedcake can be replaced with kapok seedcake in bottle culture of oyster mushroom.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.1-14
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• 1997

This experiment was conducted to find out the compositions of nutrient solution for closed system in substrate culture of cucumber. Cucumber(Cucumis sativus L. cv. Eunsung baekdadagi) plants were grown in the substrates supplied with the nutrient solutions whose strengths were 1/2, 1, and 3/2 of the original concentration developed by National Horticultural Research Station in Japan. By increasing the nutrient concentrations, plant height decreased but leaf length, leaf width, and leaf number showed little differences. A number of marketable fruit and marketable yield were the highest in the concentration of 1 strength. The nutrient compositions of solution developed for closed system in cucumber substrate culture were N 11.4, P 3.3, K 6.0, Ca 4.5, and Mg 3.5 me.$\ell$$^{-1}$ during the vegetative growth period and N 10.4, P 3.3, K 5.0, Ca 4.5, and Mg 3,5 me.$\ell$$^{-1}$ during the reproductive growth period. To examine the suitability of nutrient solution developed in the above experiment, cucumber plants were grown in the substrates supplied with different solutions and concentrations - Yamasaki's nutrient solution(Yamasaki) of 1 S, nutrient solution of Research Station for Greenhouse Vegetable and Floriculture on the Netherlands(PTG) of 1 S, nutrient solution developed in the above experiment(SCU) of 1/2, 1, and 3/2 S. EC and pH in root zone changed little in the all treatments during growing period. As cucumber plants grew, the concentrations of N, P, and K in root zone decreased but Ca concentration increased. Net $CO_2$ assimilation rate of cucumber leaves was high in SCU of 1 and 3/2 S, and Yamasaki of 1 S. Growth of cucumber plants was the lowest in SCU of 1/2 S.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.31-34
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• 1979

In this study, enzymatic hydrolysis of the substrate of the waste wood of Cortinellus edodes was investigated using crude cellulase preparation of Trichoderma viride Pers. ex. Fr. SANK 16374. The crude cellulase was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate. Reducing sugar was determined by the dinitrosalisylic acid (DNS) method. 1. The chemical composition of the waste wood was crude protein 2.26%, c. fat 2.57%, c. fibre 44.60%, c. ash 5.58% and lignin 13.62%. In amino acid composition, no cystine and methionine was showed, but trace amount of Vitamin A, $B_1$, and $B_2$, niacine and chloride were detected. (Table 1) 2. As heat treatment of the substrate was found to produce the highest reducing sugar yield being reacted for 48hr. with T.v cellulase, the substrate was heated to $190{\pm}5^{\circ}C$. for 45 min. either before or immediately after milling. 3. The substrate heated and ball milled at $190{\pm}5^{\circ}C$. for 45 min. the reducing sugar yield reached to 11.5%. 4. The substrate without any treatment was found to produce the highest reducing sugar yield being reacted 72hr. with T. v cellulase, the reducing sugar yield reached to 10.1%. 5. The rate of reducing sugar per each treated substrate was decreased by the order of the substrated, heated and then ball milled at $190{\pm}5^{\circ}C$. for 45 min. (11.5%)> without any treatment (10.1)> ball milled and heated at $190{\pm}5^{\circ}C$. for 45 min. (6.9%). 6. Saccharification of waste wood has been shown to be possible by heat treated and milling the substrate in contact with cellulase. And it is likely to be recommended that the waste wood may be valuable for raw materials of saccharification.

• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.86-91
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• 1996

Thermostable $\beta$-mannanase from Bacillus sp. YA-14 was purified by acetone precipitation, CM-cellulose, Sephadex G-100 and hydroxyapatite column chromatography from culture supernatant. The final enzyme preparation appeared to be homogeneous on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). $\beta$-Mannanase appeared to be a monomeric protein with a molecular weight of 67, 000 daltons. The optimal pH and temperature of the enzyme reaction were pH 6.0 and $75^{\circ}C$ , respectively. The enzyme was stable at a pH range of 6.0 to 9.0 and at temperatures between 45 and $85^{\circ}C$. The kinetic constants of $\beta$-mannanase as determined with a galactomannan (locust bean) as substrate were a Vmax of 25 unit/ml and a Km of 1.1 mg/ml. The enzyme had only limited activity on galactomannan substrate. It was suggested that mg $\beta$-mannanase activity is limited by the number of branched $\alpha$-galactose residues.