• Korean Journal of Microbiology
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• v.30 no.6
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• pp.546-552
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• 1992

Ethanol-tolerant strain, S. eerevisiae BUI a26 ($alc^r thr^-$) and gJucoamylase-producing strain, S diastatieus AI5a6 (STA+ hom-) were prepared by means of genetic manipulation, Protoplast fusion was carried out to introduce STA gene from AI5a6 strain to BUla26 strain, Protoplast formation was shown at 0,8 M sorbitol and 200 Jig/ml to 400 Jig/ml zymolyase treatment for 2 hours incubation, Fusion frequency was $ 3.25 {\times} 10^{-3}$ to the regenerated protoplast number using PEG 6000 for 90 min incubation. The excellent fusants with genotype of STA- $alc^r thr^-$ hom+/STA+ ($alc^s thr^+$ hom- (2n), F7 and FIO, were selected by ethanol-tolerant, ethanol fermentation, and glucoamylase production tests, Glucoamylase production of AI5a6 showed 2,7 units, but 4.2 or 8.4 units for F7 or FIO fusant at $30^{\circ}C$, Ethanol fermentation from 32% glucose by BUla26 was 14,0%(v/v) in fermentaion medium for 5 days incubation, but 14.5% or 15,0% for F7 or FIO strain, respectively. Ethanol fermentation from 5% starch was 2,0% by F7, or 1.8% by FIO strain in fermentation medium for 5 days fermentation.

• Research in Plant Disease
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• v.12 no.3
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• pp.254-259
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• 2006

Bacillus spp. isolated from mushroom medium wastes were evaluated for their biocontrol potentials on control of Sclerotinia rot of lettuce. The Bacillus isolates were more effectively obtained from waste suspension when directly added into nutrient agar(NA) medium than plating on the agar medium. Totally 42 isolates obtained from the wastes B23 and B42 showed highest antifungal activity against eight fungal pathogens such as Sclerotinia sclerotiorum, Rhizoctonia solani, Pythium ultimum, Phytophthora capsici, Fusarium oxysporum, Colletotrichum gloeosporioides, Cladosporium cucumerinum, and Botrytis cinerea and B23 and B42 were finally selected for further studies. Optimal concentration of the isolates was $10ml(10^7cfu/ml)$ to suppress the Sclerotinia rot of lettuce. Supplements such as starch, glycerol, and egg-yolk successfully maintained the bacterial population for 30 days in vitro and increased bio-control potentials against the disease. The bacterial isolate B23 alone showed 72% control value, furthermore it presented 95% control value when supplemented with 0.2% of starch, glycerol, and egg-yolk. The promising Bacillus isolates B23 and B42 were identified as Brevibacillus brevis and Bacillus stearothermophillus, respectively, based on morphological and physiological characteristics according to API database.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.391-397
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• 1995

This study was carried out to investigate the characteristics of the seedling growth and nutrients uptake at 45 day seedlings in cytoplasmic genetic male sterile lines(HR7028A, IR54756A), their restore line (Yongmoonbyeo) and check variety (Changsungbyeo). Hybrid rices had longer and more roots, heavier dry weight and lower shoot /root ratio than their parents and inbred check variety, showing heterobeltiosis in absorbed amount of inorganic elements, content of total sugar, starch and chlorophyll in plant. Different magnitude of heterobeltiosis were shown between F$_1$ hybrid rices with the same restore line; HR7028A/Yongmoonbyeo had higher heterobeltiosis than IR54756A/Yongmoonbyeo did. Hybrid rices had more number and higher $\alpha$-naphthylamine oxidizing ability of newly-grown roots in 10 day sand culture in ground water with root-cut 45 day-seedling than parental lines and inbred variety. Nunber of the newly-grown roots were positively and significantly correlated with content of total sugar, starch and absorbed amount of inorganic elements in the shoot, and content of chlorophyll in the leaf.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1229-1235
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• 1998

To see the correlation between the rate of in vitro starch hydrolysis and the glycemic index, an in vitro digestion was carried out by incubating the cereal samples for 2 hours with ${\alpha}-amylase$ in dialysis tubing. Also the levels of blood glucose were measured over 2 hours after feeding healthy volunteers with 50 g carbohydrate portions. Hydrolysis area, hydrolysis index (HI) and the dialysate content of carbohydrate throughout the digestion time for barley was significantly below those for other cereals (p<0.05), and unpolished glutinous rice was significantly above (p<0.05). The GI-glucose of barley $(57%{\pm}7)$ to glucose as standard was significantly (p<0.05) lower than those of other cereals whereas the GI-glucose of glutinous rice $(110%{\pm}8)$ was significantly higher (p<0.05) than other cereals. The GI-rice values to rice as standard were $122%{\pm}4$ for glutinous sorghum, $116%{\pm}13$ for job's tear, $115%{\pm}13$ for glutinous millet, $106%{\pm}6$ for unpolished glutinous rice, $102%{\pm}7$ for glutinous rice, $100%{\pm}0$ for rice, $90%{\pm}12$ for unpolished rice, $85%{\pm}6$ for foxtail millet, $79%{\pm}5$ for buckwheat and $63%{\pm}6$ for barley. The GI-rice was significantly correlated to hydrolysis area and HI (r=0.75, p<0.01). It suggests that the in vitro starch hydrolysis offers good potential to predict the in vivo glycemic response of starch foods.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.296-304
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• 2018

The objective of this study was to analyze the impact of climate change on rice yield and quality. Experiments were conducted using SPAR(Soil-Plant-Atmosphere-Research) chambers, which was designed to create virtual future climate conditions, in the National Institute of Crop Science, Jeonju, Korea, in 2016. In the future climate conditions($+2.8^{\circ}C$ temp, 580 ppm $CO_2$) of year 2051~2060 according to RCP 8.5 scenario, elevated temperature and $CO_2$ accelerated the heading date by about five days than the present climate conditions, resulted in a high temperature environment during grain filling stage. Rice yield decreased sharply in the future climate conditions due to the high temperature induced poor ripening. And the spikelet numbers, ripening ratio, and 1000-grain weight of brown rice were significantly decreased compared to control. The rice grain quality was also decreased sharply, especially due to the increased immature grains. In the future climate conditions, expression of starch biosynthesis-related genes such as granule-bound starch synthase(GBSSI, GBSSII, SSIIa, SSIIb, SSIIIa), starch branching enzyme(BEIIb) and ADP-glucose pyrophosphorylase(AGPS1, AGPS2, AGPL2) were repressed in developing seeds, whereas starch degradation related genes such as ${\alpha}-amylase$(Amy1C, Amy3D, Amy3E) were induced. These results suggest that the reduction in yield and quality of rice in the future climate conditions is likely caused mainly by the poor grain filling by high temperature. Therefore, it is suggested to develop tolerant cultivars to high temperature during grain filling period and a new cropping system in order to ensure a high quality of rice in the future climate conditions.

• Korean Journal of Microbiology
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• v.28 no.2
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• pp.120-127
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• 1990

Intraspecific fusion frequency between Filobasidium capsuligenum CBS6122-2 ade and met trp or met strains was $2.9\times 10^{-3}$ and $8.5\times 10^{-3}$, respectively. And intergeneric fusion frequency between Folobadidium capsuligenum CBS 4318 (cys his) and Saccharomyces cerevisiae 262-12-1 (hom3 thr1) or X2180-1A (ade thr) was $8.8\times 10^{-6}$ and $9.5\times 10^{-4}$, respectively. Nuclear fusion appears to occru in fusants between intraspecies and intergenera as strongly suggested by DNA content, nuclear staining, comparison of survival rate to UV light and mitotic segregation analysis. It was also found that $\alpha$-amylase and glucoamylase activity from intraspecific hybrids was 1.6-2.1 fold increased when compared with that from thier parents.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.93-97
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• 1991

The enzymatic properties of purified CGTase from alkalophilic Bacillus sp. YC-335 have been examined. Apparent Vmax values of the enzyme in transferring glycosyl residues ${\alpha}-,\;{\beta}-and\;{\gamma}-cyclodextrin(CD)$ to sucrose were $16.13,\;21.8\;and\;9.8{\mu}moles/min/mg\;protein$, respectively and Km values of the corresponding CD were 1.68, 0.33 and 0.37 mM, respectively. A number of saccharides, specially starch hydrolyzates such as glucose and maltose, could activate the dextrinizing activity of the enzym. However, the dextrinizing activity was inhibited by ${\beta}-CD$. It was found from Lineweaver-Burk plot that the inhibition of CGTase by ${\beta}-CD$ was noncompetitive. High performance liquid chromatographic analysis showed that the enzyme has three kinds of activity ; transglycosylation and disproportionation as well as cyclization.

• Journal of Plant Biology
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• v.17 no.4
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• pp.143-156
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• 1974

The purpose of this experiment was to study one side of germination physiology based on that protein profiles and protease relating to protein metabolism, that peroxidase, catalase, $\alpha$-amylase, $\beta$-amylase, and malate dehydrogenase involved in the carbohydrate metabolism of seed germination. All these experiments were divided into the two groups with and without acetone treatment, and were carried out. The protein bands of each germinating stage between the groups treated with and without acetone showed certain basic pattern in polyacrylamide gel disc electrophoresis. However, there was a little difference in the number of protein band, optical density, and migration velocity between two groups. The isozyme bands of peroxidase, and catalase between two groups in polyacrylamide gel disc electrophoresis did not show the numeral difference, but the optical density of certain germinating stage treated with acetone was higher than the group untreated with it and it showed their enzyme activity. The $\alpha$-amylase and $\beta$-amylase activities which involved in starch metabolism of seed germination were higher in the treated group than the other. On one hand, the protease activity of hydrolase occurred in the seeds for germination was also higher, more or less in the treated group than in the other. The isozyme band pattern of malate dehydrogenase in TCA cycle of energy metabolism pathway was very different between two groups growing for 72 hours with and without acetone treatment in cellulose acetate electrophoresis. It indicated that two isozyme bands of malate dehydrogenase was high. Consequently these experimental results mentioned above indicated that acetone treatment before sowing had an effect on dissolving certain complexed lipid substance involved in the seed coats, the activity of carbohydrate hydrolase increased with water absorption which was most comfortable in its germination, dissolved glycerin and fatty acid became certain energy source, and they stimulated the acceleration of respiration metabolism.

• KSBB Journal
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• v.14 no.6
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• pp.713-717
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• 1999

We have isolated a dextranase and amylase constitutive and hyper-producing mutant, Lipomyces starkeyi JLC26, from Lipomyces starkeyi ATCC74054 after mutation using UV irradiation. After partial purification of dextranase and amylase (together DXAMase;both activities were always co-purified) by ammonium sulfate precipitation, CM-Sepharose column chromatography, the specific activities of amylase and dextranase were 5367 and 3045 unit/mg, respectively. The pH effects for activity and stabiligy of both enzymes were similar to each other: Optimum pH and temperature for activity sere at 5.5 and 37$^{\circ}C$ and optimum ranges for stability were at pH 2.5-5.5 and 4-55$^{\circ}C$, respectively. The reaction end products of dextranase and amylase activities were found to the typical for those of endo-dextranase and endo-amylase. When the carbohydrase and maltotriose were reacted, glucose, maltose, isomaltose, maltotriose, panose and ${\alpha}(1{\rightarrow}6)$glucosylmaltotriose were produced by disproportionation reaction.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.408-413
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• 2006

We assessed the ability of a Pseudonocardia sp. from soil samples to bioconvert vitamin $D_3$. The optimal culture conditions for the bioconversion of vitamin $D_3$ to active $1{\alpha}$,25-dihydroxyvitamin $D_3$ were investigated by varying the carbon and nitrogen sources, the metal salt concentrations, the initial pH, and the temperature. Microbial transformations were carried out with the addition of vitamin $D_3$ dissolved in ethanol. They were sampled by extraction with methanol-dichloromethane and the samples were examined by HPLC. Optimum culture conditions were found to be 0.4% yeast extract, 1% glucose, 3% starch, 1% fish meal, 0.2% NaCl, 0.01% $K_2HPO_4$, 0.2% $CaCO_3$, 0.01% NaF, and pH 7.0 at $28^{\circ}C$. The optimal timing of the addition of vitamin $D_3$ for the production of calcitriol by Pseudonocardia autotrophica ID9302 was concurrent with the inoculation of seed culture broth. Maximum calcitriol productivity and the yield of bioconversion reached a value of 10.4mg/L and 10.4% respectively on the 7th day in a 75L fementer jar under the above conditions.