• Korean Journal of Microbiology
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• v.31 no.4
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• pp.318-325
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• 1993

The optima] conditions for the formation, the regeneration. and the spheroplast fusion of Flavimonas aryz/habitans spheroplasts were investigated. Cells were transformed to spherop]asts effectively by treatment of 0.5% volume (v/v) of 0.] M EDTA and ]00 flg/ml lysozyme at $37^{\circ}C$ for 30 min without shaking. Magnesium chloride and calcium chloride were effective on the stabilization of spheroplasts. and 20 mM calcium chloride in the rich regeneration medium improve the yield of regenerants as much as 3.5-fo]d. Addition of 0.8% bovine serium albumine (BSA) in dilution buffer for spheroplast formation improved the stabilization of spheroplasts over extended periods (4-6 hr) at room temperature. and thus increased the yield of recombinants to 4.5-fold. The spheroplast formation frequency and regeneration frequency of F aryzihabitans strain was 90.10% and 3.800/." respectively. The first regenerated cell of F. aryzihabitans spheroplasts were appeared 6 hours after plating. By I I hours after plating, 80% of spheroplasts were regenerated on thc rich regeneration medium containing 0.5 M sucrose. The intraspeci11c spheroplast fusion of F urvz/habitans was carried out and the properties of obtained fusants were investigated. Formation of fusion products was effective when the Flav/munas spheroplast mixture was treated with 40%(w/v) PEG6000 and 20 mM CaCl, for 10 min at room temperature. and thc formation of frequency of recombinants were $2.0{\times}10^{-5}~3.6{\times}10^{-5}$. All tested recombinant clones were very stable on further propagation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.3
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• pp.150-155
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• 2001

The hull dehydration in dough stage did not serious affect the rice yield though grain appearance texture may decline by severe occurrence of the symptom. As to white head in heading stage of rice, the occurrence of hull dehydration in 1998 was directly affected by high temperature, low air humidity and sometimes of strong wind and sunshine in early September. At harvest stage, 1,000-grain weight of brown rice was not found to be significantly different between the hull dehydrated grains and normal ones. That reason can be considered that the hull dehydration occurred hill was not injured on the leaf and rachis branches therefore the function of assimilation and translation of rice plant was not affected. The ratio of imperfect rice kernel such as green, cracked and white belly increased. The increase of cracked rice by the hull dehydration may caused by concurrent dehydration of kernel, or by insufficient water supply into kernel due to breaking of vascular bundles in glume.

• Applied Chemistry for Engineering
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• v.10 no.2
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• pp.293-298
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• 1999

Reaction mechanism was elucidated and reaction condition were optimized for the catalytic reaction synthesizing 2-methyl-4-methoxy-diphenylamine (MMDPA) which is an intermediate of Fluoran heat-sensitive dyestuff. Reactants consisted of 2-methyl-4-methoxyaniline (MMA), 3-methyl-4-nitroanisole (MNA), and cyclohexanone, and 5 wt % Pd/C was used as a catalyst. Experiments were run in an open slurry reactor equipped with reflux condenser, and products were analyzed by means of GC/MS and NMR. MMDPA yield of 90 mole % could be obtained after reaction time of 8~10 hours under the optimal reaction conditions comprising the reaction mass composition of MMA : MNA : cyclohexanone = 1 : 2 : 150 based on MMA input of 0.01 gmoles in xylene solvent, reaction temperature of $160^{\circ}C$, and catalyst amount of 0.5 g. It was found that the rate-determining step of overall reaction was dehydrogenation of the intermediate product obtained from condensation of MMA and cyclohexanone. Overall reaction rate and MMDPA yield were enhanced owing to hydrogen transfer reaction by introducing MNA together with MMA in the reaction mass. Excess cyclohexanone in the reaction mass played an important role of promoting the condensation of MMA and cyclohexanone.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.187-196
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• 2001

Asparagus varieties popular in the foreign countries were collected and tested on their productivities and qualities for five years under rain shelter and open field conditions. Among the tested varieties, cultivars of UC309 and Excel showed superior productivity to the others in spear weight but the initial growth was not different among the tested varieties. However, the growth index was higher than the other varieties. According to the result from eight-year experiment, the best variety in productivity and quality were UC309 and Excel both for rain shelter and open field cultivations. To avoid the damage caused by stem blight, rain shelter and soil surface mulching treatments were tested with var. Excel. The spear sprouting and first harvesting date were a few days earlier in rain shelter cultivation than in open field, but there were no differences among the mulching materials. The number of spears and the spear weight per plant were increased in rain shelter cultivation, especially with rice straw and black P.E. mulching treatments. Marketable yield also increased by 253% in black P.E film mulching in rain shelter cultivation compared to non-mulching in open field. The stem blight examined in the autumn, 1997 was not observed under rain shelter treatment, but severe damage was observed in the open field regardless of the mulching materials. In the experiments, high asparagus yield could be achieved by black P.E. film mulching in rain shelter cultivation without the occurrence of stem blight.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.707-714
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• 1996

Extraction behaviour of Np with DEHPA(di-(2-ethyhexyl)Phosphoric acid) from the low nitric acid solution(below 1M $HNO_3$) containing $H_2O_2$ as a reducing agent was studied at a batch system in order to establish the conditions of extraction and stripping and to enhance the extraction rate. As results, it was confirmed that the Np was mainly the pentavalent oxidation state in the low nitric acid solution. The extraction yield of Np was increased with increasing the concentration of DEHPA and $H_2O_2$ and decreased more rapidly with the increase of $HNO_3$ concentration. It was also found that the Np could be extracted into DEHPA even without the addiction any redox agents, although the extraction yield is rather low as about 70%. The extraction rate was proportional to the 0.516 power of $H_2O_2$ concentration and inversely proportional to 0.483 power of $HNO_3$ concentration as follows. $d[Np(V)]/dt=-1.391{\times}10^{-2}[H_2O_2]^{0.516}[HNO_3]^{-0.483}[Np(V)]$ Regardless of the $H_2O_2$, the Np extracted in the organic phase was effectively stripped to the aqueous phase with $H_2C_2O_4$. The Np could be stripped more than 92 % with 0.5M $H_2C_2O_4$.

• Journal of the Korean Society of Food Culture
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• v.19 no.5
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• pp.499-505
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• 2004

The present study was conducted to investigate extraction characteristics and antioxidative activity of Cassia tora L. extracts. Cassia tora L. was extracted by reflux extraction under different extraction conditions including solvent. The solid yield, turbidity, color value, titratable acidity, free sugar contents, electron donating ability and superoxide dismutase-like ability of Cassia tora L. extracts were determined. The highest solid yield value was obtained with water of 10 fold. No significant difference in turbidity and color value were found among the extracts prepared with various extraction solvents, 75% ethanol, 50% ethanol and water. The highest titratable acidity was obtained with 50% ethanol of Cassia tora L.. The free sugar contents of Cassia tora L. extracted with water showed the highest value. Cassia tora L. extracts with water included higher contents of free sugar compared with then of the other solvent extracts, 50% ethanol and 75% ethanol extracts. The total polyphenol compound content of Cassia tora L. extracted with 50% ethanol showed the highest value. Cassia tora L. extracts with 50% ethanol included higher contents of total polyphenol compound compared with those of the other solvent extracts, water and 75% ethanol extracts.

• Journal of the Korean Society of Food Culture
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• v.19 no.5
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• pp.484-490
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• 2004

The present study was conducted to investigate extraction characteristics and antioxidative activity of Schiznadra chinensis extracts. Schiznadra chinensis was extracted by reflux extraction(RE) under different extraction conditions including solvent. The solid yield, turbidity, color value, titratable acidity, free sugar contents, electron donating ability(EDA) and superoxide dismutase(SOD)-like ability of Schiznadra chinensis extracts were determined. The highest solid yield value was obtained with water of 10 fold. No significant difference in turbidity and color value were found among the extracts prepared with various extraction solvents, 75% ethanol, 50% ethanol and water. The highest titratable acidity was obtained with water extracts of Schiznadra chinensis. The free sugar contents of Schiznadra chinensis extracted with water showed the highest value. Schiznadra chinensis extracts with water included higher contents of free sugar compared with those of the other solvent extracts,50% ethanol and 75% ethanol extracts. The total polyphenol compound content of Schiznadra chinensis extracted with 50% ethanol showed the highest value. Schiznadra chinensis extracts with 50% ethanol included higher contents of total polyphenol compound compared with those of the other solvent extracts, water and 75% ethanol extracts. The electron donating ability of extracts were 60.87% in water, 57.24% in 50% ethanol, and 55.61% in 75% ethanol.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.211-215
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• 2015

The hydrolysis of defatted rice bran using near-critical water was performed, and the feasibility of consequent hydrolyzate as a growth medium was investigated by the cultivation of Saccharomyces cerevisiae. The near-critical water hydrolysis was carried out through a series of batch experiments, and the contents of total carbohydrates, disaccharides, and monosaccharides, total organic carbon (TOC), total nitrogen (TN), pH of products were measured. The growth rate of Saccharomyces cerevisiae was measured with optical density. The yield of total carbohydrates, TOC, and TN increased with temperature below $240^{\circ}C$, however, decreased above $240^{\circ}C$. The decrease of yields above $240^{\circ}C$ was caused by the formation of organic acids, and it agreed with the change of pH of products. The yield of glucose was a maximum at $200^{\circ}C$ and it decreased dramatically at higher temperature. The growth rate of Saccharomyces cerevisiae cultivated in the hydrolyzate was similar with that in the commercial medium under certain conditions. The growth rate was correlated with the content of glucose in hydrolyzate.

• Korean Journal of Acupuncture
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• v.18 no.1
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• pp.165-170
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• 2001

A rapid increasing in cultivation area due to favorable price temporarily and decreasing in consumer's demands caused by economic depressions recently, lead the price of Cynanchum wilfordii Hemsley to decline sharply. Thus, it may give rises to weakening of cultivation bases in Cynanchum wilfordii Hemsley. To investigate optimal mechanical peeling conditions of Cynanchum wilfordii Hemsley, protruded rubber, plastic pad, diamond shape's steel and palstic brush were introduced as blades and artificial stone, sand and small pebble were done as abrasives. The main results obtained were summarized as follows; 1. It took 2 minutes per 1kg in mechanical peeling of Cynanchum wilfordii Hemsley's raw root whereas 36 minutes in manual peeling and values of lightness showed more higher in manual peeling than in mechanical peeling. 2. Yield in combination of diamond shape's steel blade and sand abrasive showed the lowest at 89.9% among treatments and peeling rates in combination of diamond shape's steel blade and small pebble showed the highest at 71.3% in mechanical peeling. 3. Lightness, one of the most important factors in determining quality of Cynanchum wilfordii Hemsley, showed the highest in combination of diamond shape's steel blade and small pebble brasive at 61.90 in mechanical peeling. 4. As the speed of rotation gets faster, yields tend to lower in mechanical peeling. Peeling rates and lightness showed the highest at 66.8%, 57.96 respectively among treatments at 30 r.p.m. in mechanical peeling.

• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.37-37
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• 2015

dsRNA was found in malformed cultures of Lentinula edodes strain FMRI0339, one of the three most popular sawdust cultivated commercial strains of shiitake, and was also found in healthy-looking fruiting bodies and actively growing mycelia. Cloning of the partial genome of the dsRNA revealed the presence of the RdRp sequence of a novel L. edodes mycovirus (LeV), and sequence comparison of the cloned amplicon showed an identical sequence to known RdRp genes of LeV found in strain HKA. The meiotic stability of dsRNA was examined by measuring the ratio of the presence of dsRNA among sexual monokaryotic progeny. More than 40% of the monokaryotic progeny still contained the dsRNA, indicating the persistence of dsRNA during sexual reproduction. Comparing the mycelia growth of monokaryotic progeny suggested that, although variations in the growth rate existed among progeny and virus infection was observed in highly actively growing progeny, there appeared to be a tendency toward a lower frequency of virus incidence in actively growing progeny. This study attempted to cure the edible mushroom L. edodes strain FMRI0339 of the L. edodes mycovirus (LeV) in order to obtain an isogenic virus-free fungal strain as well as a virus-infected strain for comparison. Mycelial fragmentation, followed by being spread on a plate with serial dilutions resulted in a virus-free colony. Viral absence was confirmed with gel electrophoresis after dsRNA-specific virus purification, Northern blot analysis, and PCR using reverse transcriptase (RT-PCR). Once cured, all of fungal cultures remained virus-free over the next two years. Interestingly, the viral titer of LeV varied depending on the culture condition. The titer from the plate culture showed at least a 20-fold higher concentration than that grown in the liquid culture. However, the reduced virus titer in the liquid culture was recovered by transferring the mycelia to a plate containing the same medium. In addition, oxygen-depleted culture conditions resulted in a significant decrease of viral concentration, but not to the extent seen in the submerged liquid culture. Although no $discernable phenotypic changes in colony morphology were observed, virus-cured strains showed significantly higher growth rates and mycelial mass than virus-infected strains. We were also explored effects of LeV on fruiting body formation and mushroom yield. The fruiting body formation yield of virus-free L. edodes was larger than virus-infected L. edodes. These results indicate that LeV infection has a deleterious effect on mycelial growth and fruiting body formation. In addition, we have been investigated host-parasite interaction between L. edodes and its mycovirus interaction to study viral mechanism by establishment of proteomics.