• KSBB Journal
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• v.14 no.5
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• pp.578-584
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• 1999

The lectin was purified through 0.15 M NaCl extraction, ammonium sulfate precipitation, sepharose 4B affinity chromatography and gel filtration using sephadex G-150 from the leaves of Visum album collected in Mt. Duk Yu. The final gel filtration step resulted in 11.64 folds purification with 0.14% of recovery yield. We also performed biochemical characterization of the purified Visum album lectin. HPLC analysis of lectin purified by gel filtration revealed a singel peak. The analysis of the purified lectin by SDS-PAGE showed a tetramer composed of two identical subunits with molecular weights of 32 and 30 kDa. The lectin was a glycoprotein containing 14.4% carbohydrate, which consist of glucose, fructose, arabinose and xylose, and the amino acids such as phenylalanine, lysine and tyrosine. The purified lectin agglutinated human red blood cell types with similar potency, but when tested against red blood cells from mouse, bovine, rabbit, chicken and porcine, significant difference in potency were observed. Hemaggluting activity was inhibited by D-galactose, D-mannose, D-lactose and D-raffinose, but not by D-glucose, D-glucosamine, D-mannosamine, L-fructose, D-xylose, D-arabinose, D-galacturonic acid, D-fructose, L-rhamnose and N-acetyl-D-galactosamine. The optimal pH and thermal stability of the purified lectin were pH 4.0-7.0 and 20-5$0^{\circ}C$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.11
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• pp.1465-1471
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• 2007

Response surface methodology (RSM) was employed to optimize extraction conditions in order to find the maximal functional properties of fluid Cheonggukjang. Based on central composite design, a study plan was established with variations of microwave power, ethanol concentration, and extraction time. Regression analysis was applied to obtain a mathematical model. The maximum inhibitory of tyrosinase activity was found as 26.75% at the conditions of 30.56W microwave power, 2.40 g/mL of ratio of solvent to sample content and 10.00 min extraction time, respectively. The maximum superoxide dismutase (SOD)-like activity was 53.23% under the extraction conditions of 108.42 W, 4.38 g/mL and 7.84 min. Based on superimposition of three dimensional RSM with respect to extraction yield, inhibitory of tyrosinase activity and SOD-like activity obtained under the various extraction conditions, the optimum ranges of extraction conditions were found to be microwave power of $55{\sim}75$ W, ratio of solvent to sample content of $2{\sim}5$ g/mL and extraction time of $3.5{\sim}15$ min, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.817-823
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• 2009

This study was conducted to determine the optimal extraction conditions for maca by comparing the yields, total polyphenol contents, superoxide dismutase (SOD)-like activity and the nitrite scavenging ability. The proximate composition analysis showed 6.57% moisture, 12.83% crude protein, 1.05% crude fat, 4.80% ash and 74.75% carbohydrate. Maca was extracted with 7 different solvents (water, methanol, ethanol, acetone, ethyl acetate, chloroform and hexane) and the extracts were tested for biological activities. The extraction yields of water, methanol and ethanol extracts were 46.2%, 21.4% and 16.8%, respectively. Acetone, ethyl acetate, chloroform and hexane exhibited very low extraction yield, ranging from 0.2 to 1.0%. Total polyphenol contents and the nitrite scavenging ability were the highest in water extract. Electron donating ability and the SOD-like activity were the highest in methanol extract. When water extract was drawn out at different extraction temperatures (30, 70, $100^{\circ}C$) and time (1, 3, 5 hr), the improved biological activities (total polyphenol contents, electron donating ability, SOD-like activity and nitrite scavenging ability) were found in extracts treated at $100^{\circ}C$ for 3 or 5 hrs.

• Journal of Mushroom
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• v.8 no.3
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• pp.131-136
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• 2010

This study was performed to determine the optimal concentration of carbon dioxide, which effects mushroom growth and yield. It was shown that the periods for fruiting initiation, growth and harvest of Flammulina velutipes were increased when the $CO_2$ concentration was raised. In general, those characteristics were less affected in brown strains than in white ones. Especially brown strain ASI4103 was susceptible to changes in $CO_2$ concentration. Yields per bottle and individual mushroom weight also decreased in most strains when $CO_2$ levels increased. We were unable to designate any tendency in the number of fruiting bodies due to the large variation within each respective strain. Finally, water contents in the fruiting bodies were found to decline under high $CO_2$ concentrations.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.309-315
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• 2000

Panax ginseng is an important medicinal plant that has been used worldwide for geriatric, tonic, stomachic, and aphrodisiac treatments. Ginsenosides contained in the ginseng root are the main substances having active functions for human body. The price of ginseng is very expensive due to a complex process of cultivation, and the yield of ginseng is limited, which cannot meet the demand of the increasing market. Researchers have applied plant biotechnology to solve the problems but there are still things to be determined towards ginsenoside production by large-scale adventitious root culture. In this experiment, 5 to 20 liter bioreactors were employed to determine optimal conditions for adventitious root culture and ginsenoside production of Panax gineng. Callus was induced from the ginseng root on MS agar medium containing 1.0 mg. $L^{-1}$ 2,4-D and 0.1 mg. $L^{-1}$ kinetin. Then the callus was cultured on MS agar medium supplemented with 2.0 mg. $L^{-1}$ IBA, 0.1 mg. $L^{-1}$ kinetin, and 30 g. $L^{-1}$ to induce adventitious roots. The maximum root growth and ginsenoside production were obtained in 1/2 MS medium. 2.0 mg. $L^{-1}$ naphthalene acetic acid resulted in greater root growth than 2.0 mg $L^{-1}$ indole-3-butyric acid. Ginsenoside content increased with 2.0 mg. $L^{-1}$ benzyl adenin or kinetin. High concentrations of benzyl adenin (above 3.0 mg. $L^{-1}$ ) decreased the adventitious root growth and ginsenoside productivity. N $H_{4}$$^{+}$ inhibited the ginsenoside accumulation, while high concentrations of $K^{+}$, $Mg_{2}$$^{+}$, and $Ca_{2}$$^{+}$ increased it. N $H_{4}$$^{+}$ at 0.5 and 1.0 times of the normal amount in 3/4 SH medium resulted in the greatest biomass increase, but the highest ginsenoside productivity was obtained when N $O_{3}$$^{-}$ was used as the sole nitrogen source in the medium. Most microelements at high concentrations in the medium inhibited the root growth, but high concentrations of MnS $O_4$enhanced the root growth. Root dry weight increased with increasing sucrose concentrations up to 50 g. $L^{-1}$ , but decreased from 70 g $L^{-1}$ Ginsenoside productivity was maximized at the range of 20 to 30 g. $L^{-1}$ sucrose. In the experiment on bioreactor types, cone and balloon types were determined to be favorable for both adventitious root growth and ginsenoside production. Jasmonic acid was effective for increasing ginsenoside contents and Rb group ginsenosides mainly increased. These results could be employed in commercial scale bioreactor cultures of Panax ginseng.x ginseng.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.267-275
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• 1992

Remote afterloading high dose rate brachytherapy (HDRB) is a new technology and needs new biological principle for time and dose schedule. Here, authors attempt to evaluate the technique and clinical outcome in 116 patients, 590 procedures peformed at Asan Medical Center for 3 years. From Sep. 1989 to Aug 1992, 471 procedures of intracavitary radiation in 58 patients of cervical cancer and 26 of nasopharyngeal cancer,79 intraluminal radiation in 12 of esophageal cancer, 11 of endobronchial cancer and 1 Klatskin tumor and 40 interstitial brachytherapy in 4 of breast cancer, 1 sarcoma and 1 urethral cancer were performed. Median follow-up was 7 months with range $1\~31$ months. All procedures except interstitial were performed under the local anesthesia and they were all well tolerated and completed the planned therapy except 6 patients. 53/58 patients with cervical cancer and 22/26 patients with nasopharynx cancer achieved CR. Among 15 patients with palliative therapy, $80{\%}$ achieved palliation. We will describe the details of the technique and results in the text. To evaluate biologic effects of HDRB and optimal time/dose/fractionation schedule, we need longer follow-up. But authors feel that HDRB with proper fractionation schedule may yield superior results compared to the low dose rate brachytherapy considering the advantages of HDRB in safety factor for operator, better control of radiation dose and volume and patients comfort over the low dose brachytherapy.

• Research in Plant Disease
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• v.21 no.4
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• pp.315-320
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• 2015

Soybean mosaic virus (SMV) is a prevalent pathogen that causes significant yield reduction in soybean production worldwide. SMV belongs to potyvirus and causes typical symptoms such as mild mosaic, mosaic and necrosis. SMV is seed-borne and also transmitted by aphid. Eleven SMV strains, G1 to G7, G5H, G6H, G7H, and G7a were reported in soybean varieties in Korea. A reverse transcription loop-mediated isothermal amplification (RT-LAMP) method allowed one-step detection of gene amplification by simple procedure and needed only a simple incubator for isothermal template. This RT-LAMP method allowed direct detection of RNA from virus-infected plants without thermal cycling and gel electrophoresis. In this study, we designed RT-LAMP primers named SML-F3/B3/FIP/BIP from coat protein gene sequence of SMV. After the reaction of RT-LAMP, products were identified by electrophoresis and with the detective fluorescent dye, SYBR Green I under daylight and UV light. Optimal reaction condition was at $58^{\circ}C$ for 60 min and the primers of RT-LAMP showed the specificity for nine SMV strains tested in this study.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.374-380
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• 2006

In this study, glucose, sucrose, and dextrin were found to be better carbon sources for the production of pullulan by Aureobasidium pullulans HP-2001. Maximal production of pullulan with 200 g/l sucrose as a carbon source was 54.2 g/l. The highest yield of pullulan from sucrose was 0.40, when the sugar concentration was 100 g/1. Optimal conditions for the continuous production of pullulan by A. pullulans HP-2001 in a 7-1 bioreactor were determined by studying the effects of composition of feed solution, dilution rate, and concentration of sucrose in the feed solution. Pullulan concentration and productivity with 100 g/l glucose and 2.5 g/l yeast extract were 38.1 g/l and 0.53 g/l h for 72 h, respectively, in a batch culture of A. pullulans HP-2001. When the substituted medium contained 100 g/l sucrose, 2.5 g/l yeast extract, and mineral salts, which is the same composition as the medium for the production of pullulan, the pullulan concentration and productivity were 74.9 g/l and 0.55 g/l h for 120 h, respectively. The production of pullulan at the steady state increased with a dilution rate up to 0.015/h, and its concentration was 78.4 g/l with a weight average molecular weight ($M_w$) of $4.0{\times}10^5$. Unlike a batch culture, however, the decline of the $M_w$ and the number average molecular weight ($M_n$) of pullulan was not found in the continuous culture of A. pullulans HP-2001. When the concentration of sucrose in the feed solution was 200 g/l, 113.5 g/l of pullulan was obtained at the steady state. The steady state was maintained longer in the continuous culture fed with the feed solution containing 200 g/l sucrose than when fed with the feed solutions containing either 100 or 150 g/l sucrose.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.92-100
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• 2017

Acetoin (AC) is a volatile platform compound with various potential industrial applications. AC contains two stereoisomeric forms: (3S)-AC and (3R)-AC. Optically pure AC is an important potential intermediate and widely used as a precursor to synthesize novel optically active materials. In this study, chiral (3R)-AC production from meso-2,3-butanediol (meso-2,3-BD) was obtained using recombinant Escherichia coli cells co-expressing meso-2,3-butanediol dehydrogenase (meso-2,3-BDH), NADH oxidase (NOX), and hemoglobin protein (VHB) from Serratia sp. T241, Lactobacillus brevis, and Vitreoscilla, respectively. The new biocatalyst of E. coli/pET-mbdh-nox-vgb was developed and the bioconversion conditions were optimized. Under the optimal conditions, 86.74 g/l of (3R)-AC with the productivity of 3.61 g/l/h and the stereoisomeric purity of 97.89% was achieved from 93.73 g/l meso-2,3-BD using the whole-cell biocatalyst. The yield and productivity were new records for (3R)-AC production. The results exhibit the industrial potential for (3R)-AC production via whole-cell biocatalysis.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.101-106
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• 2003

Soybean curd was prepared using cuttlebone powder treated with acetic acid (ATC), and its characteristics were determined. Soybean protein was coagulated by adding calcium chloride, magnesium chloride, and ATC at 0.7, 1.2, and 0.9%, respectively, or higher. Yield, white index, texture, and sensory evaluations revealed the optimal concentration of ATC for preparation of soybean curd was 2.0% of total soybean weight. The proximate compositions of soybean curd prepared by adding 2.O% ATC were 75.9%, 12.6%, 1.9%, 5.3%, 6.60, and $1.0×10^4$ CFU/g in for moisture, crude protein, crude ash, crude lipid, pH, and viable cell count, respectively. Although white index and mineral content of both soybean curds were similar, texture of ATC-prepared soybean curd was superior to that of soybean curd prepared with 1.5% calcium chloride.