• KSBB Journal
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• v.20 no.6
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• pp.443-446
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• 2005

Hydrogen fermentation from food waste was attempted at different hydraulic retention time(HRT, 18-42 h). A continuous reactor fed with ground, alkali-treated and diluted food waste(average VS 4.4%) exhibited stable hydrogen production during 126 days. Hydrogen production depended on HRT, resulting in the maximum values of 25.8 mL $H_2/g\;VS_{added}$, 0.36 mol $H_2/mol\;hexose_{added}$ and 0.91 L $H_2/L/d$ at HRT 30 h. n-Butyrate and isopropanol production increased with hydrogen production increased, while acetate production decreased. The fermentation efficiency ranged from 53.3 to 65.7%, which implied that hydrogen fermentation would substitute conventional acidogenesis of food waste.

• Biomedical Science Letters
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• v.11 no.3
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• pp.327-332
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• 2005

Sf21 cells become popular as the host permissive cell line to support the baculovirus AcNPV replication and protein synthesis. The cells grow well on TC-100 medium that contains $0.1\%$ D-glucose as the major carbon source, strongly suggesting the presence of endogenous glucose transporters. However, unlike human glucose transporters, very little is known about the characteristics of the endogenoussugar transporter(s) in Sf21 cells. Thus, some kinetic properties of the sugar transport system were investigated, involving the uptake of 2-deoxy-D-glucose (2dG1c). In order to obtain a true measure of the initial rate of uptake, the uptake of $[^3H]2dGlc$ from both low $(100{\mu}M)$ and high (10 mM) extracellular concentrations was measured over periods ranging from 30 sec to30 min. The data obtained indicated that the uptake was linear for at least 2 min at both concentrations, suggesting that measurements made over a 1min time course would reflect initial rates of the jexpse uptake. To determine $K_m\;and\;V_{max}$ of the endogenous glucose transporter(s) in Sf21 cells, the uptake of 2dG1c was measured over a range of substrate concentrations $(50{\mu}M\~10mM)$ 2dG1c uptake by the Sf21 cells appeared to involve both saturable and non-saturable (or very low affinity) components. A saturable transport system for 2dG1c was relatively high, the $K_m$ value for uptake being < 0.45 mM. The $V_{max}$ value obtained for 2dG1c transport in the Sf21 cells was about 9.7-folds higher than that reported for Chinese hamster ovary cells, which contain a GLUT1 homologue. Thus, it appeared that the transport activity of the Sf21 cells was very high. In addition, the Sf21 glucose transporter was found to have very low affinity for cytochalasin B, a potent inhibitor of human erythrocyte glucose transporter

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.255-261
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• 1988

For the purpose of fermentation control and edible period extension of lower salted Kimchi, the contents and compositions of pectic substances in Kimchi, by adding 2 percent salt and 0.4 percent sodium malate buffer(SMB), fermented at $20^{\circ}C$ were investigated. Edible period of SMB added chinese cabbage Kimchi was extended 40 hrs compared to that of control (added 2.5% salt) with good flavor, texture and freshness. The contents of alcohol insoluble solid(AIS) and protopectin(PP) of control were more decrensed during fermentation than those of SMB added Kimchi. But, the contents of pectic adid(PA) and water soluble pectin(WSP) of control were more increased during fermentation than those of SMB added Kimchi. Hexose and pentose from hemicellulose in control, PP and PA respectively, were more decreased during fermentation than those in SMB added Kimchi. Lower polarity and higher molecular weight PP was eluted and higher polarity and lower molecular weight PP was decreased considerably in control compared to those in SMB added Kimchi during fermentation.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.765-771
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• 2011

This study was conducted to investigate the effect of heat treatment on the start-up performance for anaerobic hydrogen fermentation of food waste. The result showed that hydrogen production was $0.61{\pm}0.31$ mol $H_2$/mol hexose with heat-treatment of food waste at $70^{\circ}C$ for 60 min whereas it was $0.36{\pm}0.31$ mol $H_2$/mol hexose without heat-treatment of one. The heat treatment of food waste enhanced hydrogen yield due probably to the increase of hydrolysis as well as the decrease of non-hydrogen fermentation microorganisms. The removal efficiency of carbohydrate in reactors regardless of heat treatment of food waste maintained over 90%. The hydrogen conversion efficiency from food waste was 1.7-6.3% with heat-treatment whereas it was 0.7-4.5% without heat-treatment. At the time of switchover from batch to continuous operation, lactate concentration was high compared to the n-butyrate concentration in anaerobic hydrogen fermentation reactor without heat-treatment. Anaerobic hydrogen fermentation of food waste with heat treatment was stable in start-up periods because lactate concentration could be maintained at a relatively low compared to n-butyrate concentration due to the decrease of non-hydrogen fermentation microorganisms.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.41-50
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• 2017

The design of proper agitation system is requisite in biological waste treatment and energy generation plant, which is affected by viscosity, impeller types, and power consumption. In the present work, hydrogen fermentation of food waste was conducted at various operational pHs (4.5~6.5) and substrate concentrations (10~50 g Carbo. COD/L), and the viscosity of fermented broth was analyzed. The $H_2$ yield significantly varied from 0.51 to $1.77mol\;H_2/mol\;hexose_{added}$ depending on the pH value, where the highest performance was achieved at pH 5.5. The viscosity gradually dropped with shear rate increase, indicating a shear thinning property. With the disintegration of carbohydrate, the viscosity dropped after fermentation, but it did not change depending on the operational pH. At the same pH level, the $H_2$ yield was not affected much, ranging $1.40{\sim}1.86mol\;H_2/mol\;hexose_{added}$ at 10~50 g Carbo. COD/L. The zero viscosity and infinite viscosity of fermented broth increased with substrate concentrations, from 10.4 to $346.2mPa{\cdot}s$, and from 1.7 to $5.3mPa{\cdot}s$, respectively. There was little difference in the viscosity value of fermented broth at 10 and 20 g Carbo. COD/L. As a result of designing the agitation intensity based on the experimental results, it is expected that the agitation intensity can be reduced during hydrogen fermentation. The initial and final agitation intensity of 30 g Carbo. COD/L in hydrogen fermentation were 26.0 and 10.0 rpm, respectively. As fermentation went on, the viscosity gradually decreased, indicating that the power consumption for agitation of food waste can be reduced.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.268-273
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• 1996

An extremely cadmium tolerant yeast, Hansenula anomala B-7 used to determine the modification of the intracellular enzyme activities by cadmium ion. The activities of alcohol dehydrogenase, phosphofructokinase, and cytidine deaminase were decreased up to 90%, 40%, and 86% compa- red with the control by 1 mM cadmium nitrate respectively, but the activities of malate dehydrogenase, 6- phosphogluconate dehydrogenase, cytochrome c oxidase, and alkaline phosphatase were increased up to 440%, 136%, 260% and 155% compared with the control by 1 mM cadmium nitrate respectively. These results show that the activities of the enzymes participating in Embden-Mayerhof pathway (e.g. anaerobic metabolism) were reduced by cadmium, but those involved in hexose monophosphate pathway and tricarboxylic acid cycle (e.g. aerobic metabolism) were stimulated in contrast. It has been suggested that the diminished activity of cytidine deaminase in pyrimidine nucleotide dissimilation occured due to the inhibited nucleotide dissimilation by cadmium ion; the enhanced activity of cytochrome c oxidase was specifically required in order to oxidize a raised amount of NADH and NADPH due to the increased aerobic metabolism.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.233-244
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• 2005

Guanosine fermentation process can be well predicted and analyzed by the proposed state equations describing the dynamic change of a bioreactor. Pyruvate and alanine were found to be characteristically accumulated along with the decline of the guanosine formation rate during the mid-late phase of the process. The enzymological study of the main pathways in glucose catabolism and the quantitative stoichiometric calculation of metabolic flux distribution revealed that it was entirely attributed to the shift of metabolic flux from hexose monophosphate (HMP) pathway to glycolysis pathway. The process optimization by focusing on the restore of the shift of metabolic flux was conducted and the overcoming the decrease of oxygen uptake rate (OUR) was taken as the relevant factor of the trans-scale operation. As a result, the production of guanosinewas increased from 17 g/L to over 34 g/I.

• Korean Journal of Pharmacognosy
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• v.20 no.2
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• pp.110-116
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• 1989

This study was conducted to purify and characterize a polysaccharide fraction from whole parts of Duchesnea indica (Andr.) Focke, which was previously reported to show an antitumor activity by us. The plant was extracted with 5% ethanol for 3 days in the room temperature. The extract was dialyzed by 5% ethanol, and then concentrated by extraction with $excess\;_N-butanol$, followed by gel filtration named Fr. a and b. Each was composed of gallic acid, hexose, pentose, uronic acid and protein, indicating that both fractions were tannic polysaccharide containing protein. Heat treatment of them yielded gallic acid less polysaccharides. They showed a colony stimulating factor activity.

• Proceedings of the KSAR Conference
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• 2001.10a
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• pp.55-55
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• 2001

Monosaccaride hexose, may have different role in embryo development of different species. Glucose, fructose and galactose are glycolysible substrates but their effect on embryo development is not identical. Glucose has negative effect to early embryonic stage in several species whereas it is inevitable after compaction. For fructose, it can support blastocyst formation in hamster, mouse and bovine embryo. Effect of galactose is known as detrimental even at a low concentration while glucose has adverse effect only at high concentration in hamster. (omitted)

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.28-33
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• 1987

Celluloytic bacteria, -Gram positive, Gram negative and actionmycetes-were used to study their catabolic pathways of carbohydrate. It was found that Embden-Meyerhof-Parnas(EMP) pathway and hexose monophosphate(MHP) shunt were operated in Cellulomonase sp. CS1-1, C. flavigena, and Pseudomonas fluorescens subsp. cellulosa when they were cultured in a glucose containing medium, whilst gluconate was catabolised mainly via Entner-Doudoroff(ED) pathway, and to some extend through HMP shunt. Enzymes of ED pathway in the orgamisms were induced by gluconate. On the other hand Nocardia cellulans catabolised glucose and gluconate via EMP pathway and HMP shunt. The growth rate of N. Cellulans on gluconate were much slower than that on glucose.