• Microbiology and Biotechnology Letters
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• v.20 no.1
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• pp.73-78
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• 1992

- Enzymatic synthesis of L-tryptophan(Trp) using E. coli tryptophanase has been investigated. In order to reduce the substrate inhibition by indole and to increase the product yield of L-tryptophan three different approaches have been made in this work. First, indole was intermittently fed to the reaction mixture in order to control the indole concentration at lower level. When 15 mM of indole was used as a total amount of substrate, conversion yield of 80% has been obtained with intermittent feeding while only 20% of indole was converted into L-tryptophan by conventional batch operation, The second method employed in this work was the use of cyclohexane-phosphate buffer organic two-phase system. In this system, indole was mainly partitioned into the organic-solvent phase and therefore substrate inhibition was expected to be reduced. L-Tryptophan production in organic two-phase system was, however, unexpectedly lower than that obtained in aqueous buffer solution. As a third method cyclodextrins have been added to the aqueous reaction mixture. It was found that the addition of $\beta$-cyclodextrin enhanced the tryptophan synthesis noticeably while $\alpha$-cycfodextrin showed little effect on tryptophan production.

• Journal of Korean Medicine for Obesity Research
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• v.15 no.2
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• pp.104-110
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• 2015

Objectives: The herb of Agastache rugosa (AR) is a traditional herbal medicine used for colds, vomiting and furuncles. However, there are few reports to investigate the inhibitory effects of AR on obesity. In this study, the effects of AR on high fat diet (HFD)-induced obesity and its mechanism of actions were investigated in experimental animals. Methods: The mice were fed HFD for 4 weeks to induce obesity. After randomly divided into normal fat diet, HFD and AR groups, 200 mg/kg of AR was administrated for 4 weeks with continuous HFD feeding while vehicle was orally treated to HFD group. Food intake and body weight were recorded weekly. Results: Increased body weight by HFD was improved by AR treatment. AR administration inhibited an increase of visceral fat weight as well as adipocyte hypertrophy. Hepatic steatosis was ameliorated in AR-treated mice. In addition, treatment of AR attenuated the expression of adipogenic transcription factor, peroxisome proliferator-activated receptor (PPAR)-gamma in the epididymal adipose tissue. Also the increased serum leptin level by HFD was maintained in AR group, leading to inhibition of food intake. Conclusions: AR treatment showed inhibitory effects on HFD-induced obesity by inhibition of PPAR-gamma and reduction of food intake. AR could be an alternative treatment for obesity.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.220-228
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• 1995

For polyhydroxyalkanoic acid (PHA) production, several microorganisms were isolated from sewage sludge. One of them, GB-77 strain, was chosen from its PHB/HV copolymer production on only fructose without cosubstrate. The isolated strain GB-77 was identified as the genus Alcaligenes. Optimal temperature and pH for cell growth were 36C and 6.8. Optimal medium composition was 10 g/l of fructose and 5 g/l of polypeptone, 1 $\times$ 10$^{-2}$M Na$^{2}$HP0$^{4}$, 1.3 $\times$ 10$^{-2}$M KH$^{2}$PO$^{4}$. To investigate the optimal condition for polyhydroxyalkanoic acid production two-stage culture technique was used; first stage for cell growth and second stage for PHA production on unbalanced growth conditions. Optimal conditions for high PHA production were C/N ratio 50, temperature 36$\circ$C and pH 6.8. To overcome fructose inhibition on cell growth, intermittent feeding fed-batch culture technique was used. Total cell concentration was 17.4 g/l with 9.1 g/l of PHA. The purified PHA was identified PHB/HV copolymer by NMR analysis.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.551-554
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• 2006

Inhibition of propellant temperature rising in liquid propulsion rocket using cryogenic fluid as a propellant is very important. Especially propellant temperature rising during stand-by after filling and pre-pressurization can bring into cavitation in turbo-pump. One of the method preventing propellant temperature rising in cryogenic feeding system is recirculating propellant through the loop composed of propellant tank, feed pipe, and recirculation pipe. The circulation of propellant is promoted through gas-lift effect by gas injection to lower position of recirculation pipe. In this experiment liquid oxygen and gas helium is used as propellant and injection gas. Under atmospheric and pressurized tank ullage condition, helium injection flow-rate is varied to observe the variation of recirculating flow-rate and propellant temperature in the feed pipe. There is appropriate helium injection flow-rate for gas-lift recirculation system.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1327-1338
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• 2013

The humanized anti-hepatocyte growth factor (HGF) monoclonal antibody (mAb) YYB-101 is a promising therapeutic candidate for treating various cancers. In this study, we developed a bioprocess for large-scale production of YYB-101 and evaluated its therapeutic potential for tumor treatment using a xenograft mouse model. By screening diverse chemically defined basal media formulations and by assessing the effects of various feed supplements and feeding schedules on cell growth and antibody production, we established an optimal medium and feeding method to produce 757 mg/l of YYB-101 in flask cultures, representing a 7.5-fold increase in titer compared with that obtained under non-optimized conditions. The optimal dissolved oxygen concentration for antibody production was 70% $pO_2$. A pH shift from 7.2 to 7.0, rather than controlled pH of either 7.0 or 7.2, resulted in productivity improvement in 5 L and 200 L bioreactors, yielding 737 and 830 mg/ml of YYB-101, respectively. The YYB-101 mAb highly purified by affinity chromatography using a Protein A column and two-step ion exchange chromatography effectively neutralized HGF in a cell-based assay and showed potent tumor suppression activity in a mouse xenograft model established with human glioblastoma cells.

• Preventive Nutrition and Food Science
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• v.2 no.2
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• pp.162-166
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• 1997

This study investigated the antigenotoxic effects of Synurus deltoides extract on the mutagenesis induced by benzo[a]pyene(B[a]P). About 80% and 90% antimutagenic effects were observed in the presence of over 200$\mu\textrm{g}$/plate of methanol extract of Synurus deltoides against Salmonella typhimurium TA98 and TA100 induced by B[a]P, respectively. The methanol extract itself did not induce an increased frequency of micronucleated polychromatic erythrocytes(MNPCE) irrespective of the sampling time(up to 72h), while the treatment with benzo[a]pyrene(B[a]P) at 150mg/kg significantly increased (p<0.05) the incidence of MNPCE. The strongest relative frequency of MNPCE was observed at 36h after injection of B[a]P and the most significant reduction (p<0.05) in the frequencies of MNPCE was occurred at the feeding of the methanol extract to mice 12 h before injection of B[a]P. The most significant reduction (p<0.05) with 48% was observed in the frequencies of MNPCE when 50 mg/kg of the methanol extract was given to the mice 12h before injection of B[a]P, while the strongest relative frequency inhibition was 54% at the multiple feeding of 5mg/kg of the methanol extract e time every day for 5 days on th frequencies of MNPCE induced by 150 mg/kg of B[a]P. These results indicate that the methanol extract of Synurus deltoides have a strong modulatory effect on benzo[a]pyrene induced MNPCE.

• BMB Reports
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• v.30 no.5
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• pp.370-377
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• 1997

A novel assay method is described for rapid quantitation of reaction rate of sterol ${\Delta}^7$-reductase (${\Delta}^7$-SR) which catalyzes reduction of the ${\Delta}^7$-double bond of sterols. Of six different organ tissues-liver, small intestine, brain, lung, kidney, and testis-. ${\Delta}^7$-SR activity was detected only in liver (2.30 nmol/min/mg protein) and testis (0.11 nmol/min/mg protein). Using a newly developed method which employs diet-induced enzyme proteins and ergosterol as substrate, we assessed both kinetics ($K_m=210\;{\mu}M$, $V_{max}=1.93\;nmol/min/mg$) and inhibition of the rat hepatic ${\Delta}^7$-SR against well-studied cholesterol lowering agents such as triparanol ($IC_{50}=16\;{\mu}M$). 3-$\beta$-[2-(diethylamino)ethoxy]androst-5-en-17-one (U18666A) ($IC_{50}=5.2\;{\mu}M$), and trans-1.4-bis(2-chlorobenzylaminomethyl)cyclohexane dihydrochloride (AY-9944) ($IC_{50}=0.25\;{\mu}M$). Of the three well-known AY-9944-sensitive cholesterogenic enzymes (i.e., ${\Delta}^7$-SR, sterol ${\Delta}^8$-isomerase, and sterol ${\Delta}^14$-reductase). ${\Delta}^7$-SR was found to be the most sensitive enzyme with a noncompetitive inhibition of this compound ($K_i=0.109\;{\mu}M$). Substrate specificity studies of the microsomal ${\Delta}^7$-SR indicate that the relative reaction rate for 7-dehydrocholesterol and ergosterol are 5.6-fold and 1.6-fold higher than that for lathosterol. ${\Delta}^7$-SR activity was also modulated by feeding rats a diet supplemented with 0.5% ergosterol (>2.6-fold) in addition to 5.0% cholestyramine plus 0.1% lovastatin ($\simeq$5.0-fold). Finally, microsomal ${\Delta}^7$-SR was solubilized by 1.5% 3-[3-(cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS) and enriched on PEG (0~10%) precipitation, which should be suitable for further purification of the enzyme.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.928-935
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• 2012

World Agriculture faces daunting challenges in feeding the growing population today. Reduction in arable land extent due to numerous reasons threatens achievement of food and nutritional security. Under this back ground, agricultural use of acidic soils, which account for approximately 40 % of the world arable lands is of utmost important. However, due to aluminum (Al) toxicity and low available phosphorous (P) content, crop production in acidic soils is restricted. Citrus, in this context, gains worldwide recognition as a crop adapted to harsh environments. The present paper reviewed Al toxicity and possible toxicity alleviation tactics in citrus. As reported for many other crops, inhibition of root elongation, photosynthesis and growth is experienced in citrus also due to Al toxicity. Focusing at toxicity alleviation, interaction between boron (B) and Al as well as phosphorus and Al has been discussed intensively. Al toxicity in citrus could be alleviated by P through increasing immobilization of Al in roots and P level in shoots rather than through increasing organic acid secretion, which has been widely reported in other crops. Boron-induced changes in Al speciation and/or sub-cellular compartmentation has also been suggested in amelioration of root inhibition in citrus. Despite the species-dependent manner of response to Al toxicity, many commercially important citrus species can be grown successfully in acidic soils, provided toxicity alleviation Agro-biological tactics such as addition of phosphorous fertilizers are used properly.

• YAKHAK HOEJI
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• v.37 no.6
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• pp.647-658
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• 1993

The susceptibilities of aldehyde dehydrogenase (AldDH) and alcohol dehydrogenase (ADH) to active oxygen generated by xanthine-xanthine oxidase (XOD) system were studied. Incubation of AldDH with 2$\times$10$^{-3}$ units of XOD for 30 min at $25^{\circ}C$ resulted in the decrease of enzyme activity to 30% and it was inactivated completely when incubated with 5$\times$10$^{-3}$ units of XOD. Whereas 70% of ADH activity was retained after exposure to 5$\times$10$^{-3}$ units of XOD for 30 min, 40% of ADH activity was retained after exposure to 5$\times$10$^{-2}$ unit of XOD for 30 min. This inhibition effect by the active oxygen was preventable by catalase and glutathione, but not by SOD. The rates of the NADPH-dependent oxygen consumption by the liver S-9 mixture and microsomes were also determined in this study. Rate of oxygen consumption is increased in the liver S-9 mix and microsomes from phenobarbital-treated rat, and it was consistent with increased lipid peroxidation. In the presense of ethanol as a substrate, the oxygen consumption rates were increased. It is reported that hepatic AldDH activity is depressed in alcoholic liver diseases, however there is few report that explains the reason of depressed AldDH activity. These results are supportive of the theory that the increase in hepatic ethanol oxidation through the induced ME activity after chronic ethanol feeding generate oxygen radical at elevated rates and it leads to the depression of AldDH activity.

• The Korean Journal of Food And Nutrition
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• v.34 no.5
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• pp.526-536
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• 2021

This study was conducted to investigate the anti-obesity effect of Discorea Japonica Thunb. fermented with Monascus After inducing obesity by feeding hight fat diet (diet induced obesity model: DIO) for four weeks, each 8 rats were assigned to normal (Nor), high fat diet (HF), high fat diet containing orlistat (PC), high fat diet containing different concentration of Discorea Japonica Thunb. fermented with Monascus (UPDM_L, UPDM_H) and Discorea Japonica Thunb. (UPD) extract. Although the UPD, UPDM_L (ultrafine pulverized Discorea Japonica Thunb. fermented with Monascus: 400 mg/kg) and UPDM_H (DIO oral administration ultrafine pulverized Discorea Japonica Thunb. fermented with Monascus: 800 mg/kg) showed weight gain inhibition effects, the results of poor obesity inhibition rather than PC were confirmed. However, it showed a more effective weight loss effect in UPDM_H than UPD, and significantly reduced the weight of epididymal fat and subcutaneous fat. Furthermore, the possibility of anti-obesity effects of Discorea Japonica Thunb. fermented with Monascus can be confirmed by observing the effects of reducing serum total cholesterol, triglyceride and LDL concentrations, reducing ALT and AST levels, and inhibiting fat build-up in liver tissue. It is believed that Discorea Japonica Thunb. fermented with Monascus can be expected to utilize as a functional material that is important to improve anti-obesity and metabolic syndrome.