• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.138-139
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• 2003

To investigated the effect of liquid culture conditions and nutrient sources on the formation with bioactive substance of Paeilomyces japonica and Cordyceps militaris cultivated in the country, the result are as follow; The growth temperature of two mycelia is 25$^{\circ}C$ and the proper temperature for cordycepin growth is around 20$^{\circ}C$. The formation amount of bioactive substance by nutrient sources reached its peak with using 2% glucose and 1% galactose in case of carbon sources and 0.4% inorganic compound in case of nitrogen sources. Also, the ratio of C/N was optimal with 3% glucose 1% peptone. For a natural medium, most grains were sufficient but the soybean oil was superb. The formation amount of protein-binding polysaccharide that are used for anticancer substance was in proportion to the growth rate of mycelium, had lots of aeration and showed a trend of increasing when the acidity lower. and the content of structural protein showed a trend of increasing when the acidity lower. However, the content of the structural hexosamin did not get a great the effect of culture conditions and nutrient sources. The constitution of monosaccharide that organizes a protein-binding polysaccharide greatly changed in proportion to carbon sources. When Paecilomyces japonica cultured in a silkworm larvae for 30 days, the content of cordycepin was 204.5 mg/100mL as a dry weight in the fruiting body, 41.8 mg/100mL in mycelium and larva, and the content for each bottle was average 29.5 mg/100mL. In case of Cordyceps militaris for 45days, the fruiting body was 563.5 mg/100mL, the larva and the mycelium was 86.1 mg/100mL, and the content for each bottle was average 65.0 mg/100mL.

• Korean Journal of Environmental Biology
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• v.27 no.3
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• pp.279-284
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• 2009

In order to understand food sources-metabolism for the pacific oyster (Crassostrea gigas), the stable isotope ratios of carbon (${\delta}^{13}C$) and nitrogen (${\delta}^{15}N$) of its gut, gill, and muscle as well as potential food sources (particulate organic matter, sedimentary organic matter, benthic microalgae, seagrass detritus) were determined in Dongdae Bay. Average ${\delta}^{13}C$ and ${\delta}^{15}N$ values reflect that oysters primarily fed on sedimentary organic matter as opposed to suspended organic matter during summer and winter seasons. However, the relatively enriched $^{15}N$ values of particulate organic matter (>$250{\mu}m$) and sedimentary organic matter in the summer may be due to the photosynthetic incorporation of $^{15}N$-enriched nitrogen (DIN) or the spawning events of bivalves. Specific oyster tissues (gut, gill, and muscle) revealed different metabolic pathways, which were determined through analysis of ${\delta}^{13}C$ and ${\delta}^{15}N$ in each organ. The present results suggest the determination of carbon and nitrogen stable isotopes to be a useful approach in ecological research related to the food sources- metabolism of Crassostrea gigas.

• Mycobiology
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• v.38 no.4
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• pp.274-281
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• 2010

Cordyceps cardinalis was reported in Japan and the USA in 2004, and its fruiting bodies have recently been cultured in Korea. Herbarium specimens preserved at the Cordyceps Research Institute, Mushtech, Korea were revised and identified as C. cardinalis, based on morphological characters and conidial structures. Most of the C. cardinalis specimens were collected from Mt. Halla in Jeju-do. The effects of various nutritional sources and environmental conditions such as temperature and pH on mycelial growth of C. cardinalis were studied. Oatmeal agar, Martin's peptone dextrose agar, and Schizophyllum (mushroom) genetics complete medium plus yeast extract resulted in the best mycelial growth. Among carbon sources, cereals, and nitrogen sources, maltose, oatmeal, and peptone resulted in the best mycelial growth respectively. Mineral salts helped to increase growth rate but only resulted in thin mycelial density, similar to water agar. A temperature of $25^{\circ}C$ and a pH of 7 resulted in the highest mycelial growth. Based on these results, a Cordyceps cardinalis composite medium (CCM) was formulated with 1% maltose, 2% oatmeal, 1% peptone, and 2% agar. Use of the CCM resulted in slightly better mycelial growth than that of other commonly used agar media. Only organic nitrogen sources imparted a reddish pigmentation to the agar media, but this character diminished after several subcultures. A 7 day culture duration resulted in the best mycelial growth.

• The Korean Journal of Mycology
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• v.22 no.4
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• pp.332-337
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• 1994

Under standard condition (Han, et al., 1990: glucose 1%-nitrate 0.1% minimal medium, 30 ml in 9 cm plate, $10^6$ cells of inoculum per plate), wild type of Aspergillus nidulans developed both sexual and asexual organs in ballance, while velA1 mutant developed asexual ones preferentially. Increase of glucose concentration did not significantly affect the asexual sporulation. However, development of sexual organs were largely affected. It was greatly enhanced when favorable nitrogen source, for example, casein hydrolysate was added, which is contrary to the case of Neurospora or Saccharomyces where limitation of N source induces sexual development. On most of moderate C sources asexual development in $velA^+$ strain was largely inhibited except acetate on which only asexual spores were produced, while that in velA1 mutant strain was not affected. Lactose promoted the sexual development even in velA1 mutant indicating that lactose itself or its metabolic intermediate may induce sexual development independent of allelic state of velA gene. On other moderate favorable C sources, glycerol, galactose and ethanol, asexual development was largely inhibited in $velA^+$ strain but not in velA1 mutant strain. Sexual organs were, however, never produced on acetate. These results suggested that asexual development of wild type is largely dependent on C sources and the velA gene is involved in the repression of asexual development in not-enough-grown (non-competent) thalli resulting in preferential progression of sexual development.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.273-284
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• 2020

Calocybe indica is an edible mushroom commercially cultivated in India and other tropical countries. In this study, the culture characteristics and optimal conditions of milky mushroom strains were determined. The growth temperature and pH range of milky mushrooms was extensively investigated between 15-35 ℃ and pH 3-11. For efficient cultivation, 20 types of nutrient sources were selected that consisted of one of 21 types of carbon sources, 6 organic nitrogen sources, 6 inorganic nitrogen sources, 13 amino acids, 6 organic acids and 12 inorganic salts. The impact of each of the selected nutrition sources and their concentration on growth was investigated. The optimum pH and temperature were determined to be pH 6.0 and 15 ℃, respectively. The optimum concentration of medium elements for the mycelial growth of C. indica was determined to be as follows: carbon source, 2% maltose; organic nitrogen source, 1% yeast extract; inorganic nitrogen source, 0.1% NaNO₃; amino acid, 0.7% asparagine; organic acid, 0.07% acetic acid; inorganic salt, 0.07 mM MnSO₄.

• International Journal of Control, Automation, and Systems
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• v.6 no.4
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• pp.613-619
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• 2008

A method to produce a desired current pattern in a multiple-source EIT system using voltage sources is presented. Application of current patterns to a body is known to be superior to the application of voltage patterns in terms of high spatial frequency noise suppression, resulting in high accuracy in conductivity and permittivity images. Since current sources are difficult and expensive to build, the use of voltage sources to apply the current pattern is desirable. An iterative algorithm presented in this paper generates the necessary voltage pattern that will produce the desired current pattern. The convergence of the algorithm is shown under the condition that the estimation error of the linear mapping matrix from voltage to current is small. Simulation results are presented to illustrate the convergence of the output current.

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.73-79
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• 2011

ORC(organic Rankine cycle) has potential of reducing consumption of fossil fuels and has many favorable characteristics to exploit low-temperature heat sources. This work analyzes performance of ORC with superheating using low-temperature energy sources in the form of sensible energy. Maximum mass flow rate of a working fluid relative to that of a source fluid is considerd to extract maximum power from the sources. Working fluids of R134a, $iC_4H_{10}$ and $C_6C_6$, and source temperatures of $120^{\circ}C$, $200^{\circ}C$ and $300^{\circ}C$ are considered in this work. Results show that for a fixed source temperature thermal efficiency increases with evaporating temperaure, however net work per unit mass of source fluid has a maximum with respect to the evaporating temperature in the range of low source temperature. Results also show that the maximum power extraction is possible with R134a for the source temperature of $120^{\circ}C$, with $iC_4H_{10}$ for $200^{\circ}C$, and with $C_6C_6$ for $300^{\circ}C$.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.266-271
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• 2018

Effect of plasmid curing of Acinetobacter sp. B-W on the production of siderophore from glutamic acid as both carbon and nitrogen sole sources was investigated. Plasmid cured mutant of strain B-W lost the ability to produce siderophore from glutamic acid at $28^{\circ}C$. Transformant E. coli $DH5{\alpha}$ harboring 20 kb plasmid, that was isolated from wild type of strain B-W produced siderophore from glutamic acid as both carbon and nitrogen sole sources at $28^{\circ}C$, but, not at $36^{\circ}C$. Production of siderophore from glutamic acid by transformant E. coli $DH5{\alpha}$ was completely inhibited by $10{\mu}M\;FeCl_3$. In previous report, catechol nature of siderophore produced from glutamic acid by strain B-W was detected by Arnow test. The siderophore produced from glutamic acid by transformant E. coli $DH5{\alpha}$ was also catechol type. Rf value of siderophore produced from transformant E. coli $DH5{\alpha}$ grown in medium glutamic acid as both carbon and nitrogen sole sources at $28^{\circ}C$ was 0.32 in butanol-acetic acid-water (12:3:5) as developing solvent. Rf value of the siderophore was the same with that of wild type of strain B-W. Thus a single plasmid of 20 kb seemed to be involved in the production of siderophore from glutamic acid.

• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.30-36
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• 1997

The effects of carbon and nitrogen sources on the mycelial growth and sporulation of microconidia and chlamydospores of five isolates of Cylindrocarpon destructans (Zinssm.) Scholten causing root rot of Panax ginseng were studied. For the carbon sources, fructose, glucose, maltose, and sucrose in Czapek-Dox broth showed good mycelial growth of 178∼201 mg in dry weight compared with 64 mg of the control. The best carbon sources tested for conidial formation were sucrose and maltose with 2.75 and 3.03 log conidia/ml, respectively. For the nitrogen sources, aspartic acid, NaNO3, KNO3, arginine, threonine, and leucine increased mycelial growth of the fungi to 208∼231 mg in dry weight without significant difference (p=0.05) among them. Meanwhile the growth with cystine was poor (26.3 mg dry weight), and no conidium and chlamydospore were formed. Maximum microconidial formation was observed in the media with NaNO3 and KNO3 as 3.37 and 3.35 log conidia/ml, and for the chlamydospore formation the (NH4)2SO4-containing medium and the nitrogen-absent medium were the best as 3.40 and 3.57 log chlamydospores/ml, respectively. No conidium was found in the medium without nitrogen sources, in which chlamydospore formation increased 6 times more than in the nitrogen-amended medium. However, deletion of carbon source in the medium did not affect on the formation of conidia and chlamydospores of C. destructans.

• Journal of the Korean Ceramic Society
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• v.30 no.1
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• pp.46-54
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• 1993

$\beta$-SiC was chemically vapor deposited by pyrolysis of MTS＋H2 gas mixture. The experiments were conducted in the temperature range of 1100~150$0^{\circ}C$ with a r.f. induction furnace under atmospheric pressure. The IR, XRD, EDS and AES analysis revealed that the free Si was always codeposited with SiC below 140$0^{\circ}C$, regardless of the total flow rate and MTS concentration, whereas $\beta$-SiC single phase was deposited at 150$0^{\circ}C$. C3H8 or CH2Cl2 as an excess C sources, was supplied with MTS in order to obtain stoichiometric SiC at low temperature. With the addition of C3H8 or CH2Cl2, the deposition rate was increased and $\beta$-SiC single phase could be deposited even at temperature as low as 110$0^{\circ}C$. In the absence of C3H8 or CH2Cl2, the microhardness of the layer was quite low (