• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.407-410
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• 2002

Hydrogen is considered to be a clean energy because it doesn't generate the global warming gas such as $CO_2$, SOx and NOx, after its combustion. In this study, strain YJ isolated from shore system was used to produce efficiently hydrogen using the various carbon sources such as glucose, sucrose and fructose and its characteristics were investigated in batch cultivation. The maximum hydrogen production shown that glucose, sucrose and fructose were highest obtained at 2, 4 and 5 % concentration, respectively. In addition, we investigated the effect of pH under various conditions as range of initial pH 5.5 to 8.0 pH because growth of strain YJ declined due to produced organic acids. The results showed that the highest production rate of hydrogen was obtained at pH 7.5.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.413-416
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• 2000

Panax ginseng hairy roots, transformed by Agrobacterium rhizogenes KTCT 2744, was incubated flask, and investigated its optimal growth conditions. Transformed P. ginseng hairy roots showed active branching pattern and fast growth at free-hormone medium. Optimal conditions of hairy roots showed maximum growth at $23^{\circ}C$, pH 5.8, 1/2 MS medium, 3% sucrose. Effects of combined sugar showed that it had a better growth at only sucrose without glucose or fructose than with glucose or fructose. Also the case of sucrose with glucose had a better growth than with fructose.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.323-327
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• 1987

The sugar contents of Dolwoe, which were prepared in the laboratory and marketed Korean products of Dolwoe, Japanese product of Dolwoe and Korean-roasted products of Dolwoe were analyzed and compared. The contents of total sugar and reducing sugar of stem in prepared Dolwoe tea were 2 times higher than those of leaf. The sugar content of Korean product was similar to that of Japanese, but the contents of total sugar and reducing sugar in Korean-roasted sample decreased to 17.2% and 40.9%, respectively. It was confirmed that free sugar in Dolwoe tea was composed of rhamnose, fructose, glucose and sucrose. The ratio of free sugar content was quite different between Dolwoe-leaf tea and Dolwoe-stem tea. Comparing the free sugar content in prepared Dolwoe tea, glucose was the highest followed by fructose, sucrose and rhamnose. On the other hand, in marketed Dolwoe tea, glucose was the highest substance and followed by fructose, rhamnose and sucrose. It was found that rhamnose content in Japanese product was approximately 6 times more than that of Korean.

• Biomedical Science Letters
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• v.9 no.4
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• pp.177-181
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• 2003

The baculovirus/Spodoptera frugiperda (Sf) cell system has become popular for the production of large amounts of the human erythrocyte glucose transporter, GLUT1, heterologously. However, it was not possible to show that the expressed transporter in insect cells could actually transport glucose. The possible reason for this was that the activity of the endogenous insect glucose transporter was extremely high and so rendered transport activity resulting from the expression of exogenous transporter very difficult to detect. Sf21-AE cells are commonly employed 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 the human glucose transporter, very little is known about properties of the endogenous sugar transporter(s) in insect cells. Thus, the uptake of 2-deoxy-D-glucose (2dGlc) by Sf21-AE cells and the inhibition of 2dGlc transport in the insect cells by fructose and cytochalasin B were investigated in the present work. The binding assay of cytochalasin B was also performed, which could be used as a functional assay for the endogenous glucose transporter(s) in the insect cells. Sf21-AE cells were infected with the recombinant virus AcNPV-GT or no virus, at a multiplicity of infection (MOI) of 5. Infected cells were resuspended in PBS plus and minus 300 mM fructose, and plus and minus 20 $\mu$M cytochalasin B for use in transport assays. Uptake was measured at 28$^{\circ}C$ for 1 min, with final concentration of 1 mM deoxy-D-glucose, 2-[1,2-$^3$H]- or glucose, L-[l,$^3$H]-, used at a specific radioactivity of 4 Ci/mol. The results obtained demonstrated that the sugar uptake in uninfected cells was stereospecific, and was strongly inhibited by fructose but only poorly inhibitable by cytochalasin B. It is therefore suggested that the Sf21-AE glucose transporter has very low affinity for cytochalasin B, a potent inhibitor of human erythrocyte glucose transporter.

• Journal of the Korean Applied Science and Technology
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• v.2 no.1
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• pp.57-66
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• 1985

The possible effects of 10% carbohydrate containting diets on the serum glucose and lipids values were studied with normal and alloxan - diabetic male rats for a period of 28 days. The diets were supplemented with either glucose, cornstarch or sucrose, fructose or the basal diet containing no added carbohy drates. After this period, 3 to 4 rats among the each group were killed and samples of serum, liver, spleen and kidney were collected. The others were rendered diabetic by the intraperitoneal injection of alloxan ($190mg/\frac{wt}{kg}$). Then original feeding scedule was continued for 3 days in all five diabetic groups, before the collection of tissue samples and serum. Feeding the nondiabetic rats with glucose and fructose delayed the bodyweight development relatively compared with nonsugar group. The weight deductions after alloxan injection were similar in all feeding groups. All diabetic animals exhibited increased blood glucose triglceride levels but almost unchanged total cholesterol values. Blood glucose values for nondiabetic rats were normal ranges, and then glucose feeding group was the highest. Total - cholesterol values were the highest in nondiabetic rats fed glucose, fructose and in diabetics fed sucrose, glucose. Triglyceride values were the highest in nondiabetic rats fed sucrose, and no difference in diabetic rats. Some cornstarch group exhibited fatty-livers in diabetic and nondiabetic, and more studies need.

• Korean Journal of Microbiology
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• v.35 no.2
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• pp.146-152
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• 1999

Acceplor reaction of glucosyltr~ansferase of Streptococcus ,SO~~-~IZLIS with f ~ ~ t o ~ y l o l i g o ~ a ~ ~ h a r i d e ~ was studied for the biosynthesis of novel olgisaccharides. First, bacilracin resistant mutants were selected by mutagenesis of Streptococcus sobrimis ATCC27351. Among these mutants 4 strains were selected by resistance to bacitracin and increase of glucosyltransferase. Acceptor reaction of maltose was analyzed by TLC and image analysis. There were differences in the specificity of the acceptor reaclion by Ule glucosylumsferase between mother strain (Streptococcus sobrinus ATCC2735) and bacitracin resistant mutants (Streptococcus sobrinus BR24C, Strepfococcus sobrinus CH-5). Molher strain did ilot show an acceptor reaction with fructosyloligosaccharides such as 1-keqtose and nystose. Acceptor reaction products of turailose and 1-kestose with glucosyltransferase (GW-S) of Streptococcus sobrini~s BR24C were TEX>\6^{3}$-$\alpha$-D-glucopyranosyl \3^{2}$-O-$\alpha$-D-fructose (glucose-fructose-glucose) and \6^{4}$-$\alpha$-D-glucopyranosyl \1^{3}$-$\beta$-D-~-h~ctofuranos~~ sucrose (glucose-glucosefructose- fructose). respectively These are novel oligosaccharides which can be produced only by enzymatic reaction.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.722-728
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• 2002

Eight strains producing bacterial cellulose (BC) were isolated from rotten fruits and traditionally fermented vinegars. One of the isolated strains from the rotten grape in Gwangju, Korea, maintained a relatively stable BC production in shaking cultures. This isolated strain proved to be Acetobacter xylinum, based on several biochemical and morphological tests. It was shown that the slant-baffled flask was more efficient than the conventional flask for the BC production in shaking cultures. To determine the most suitable carbon and nitrogen sources for the production of BC, various compounds were examined. Fructose was found to be the most effective carbon source with an optimal concentration of 2%. Mixed carbon source (glucose:fructose=1:3) was also better than glucose or fructose alone. Optimal nitrogen source, when basal medium was used, was 10% (v/v) com steep liquor (CSL). When com steep liquor was used with a mixed carbon source (glucose:fructose=1 :3),4% CSL exhibited the best BC production. Based on these results, a defined medium was developed for the BC production by Acetobacter xylinum KJ-1. When this medium was used under optimal culture conditions, the BC production was 7.2 g/1, which was approximately 3 times higher than that with the traditional HS medium.

• BMB Reports
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• v.32 no.5
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• pp.429-435
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• 1999

Unlike the mammalian glucose transporter GLUT1, little is known about the nature of the endogenous sugar transporter(s) in insect cells. In order to establish the transport characteristics and other properties of the sugar transport proteins of Sf9 cells, a series of kinetic analyses was performed. A saturable transport system for hexose uptake has been revealed in the insect cells. The apparent affinity of this transport system(s) for 2-deoxy-D-glucose was relatively high, the $K_m$ for uptake being <0.5 mM. To further investigate the substrate and inhibitor recognition properties of the insect cell transporter, the ability of other sugars or drugs to inhibit 2-deoxy-D-glucose transport was examined by measuring inhibition constants ($K_j$). Transport was inhibited by D-mannose, D-glucose, and D-fructose. However, the apparent affinity of the C-4 epimer, D-galactose, for the Spodoptera transporter was relatively low, implying that the hydroxyl group at the C-4 position may play a role in the strong binding of glucose and mannose to the transporter. The results also showed that transport was stereoselective, being inhibited by D-glucose but not by L-glucose. It is therefore concluded that insect cells contain an endogenous glucose transport activity that in several aspects resembles the human erythrocyte glucose transporter. However, the mammalian and insect transporters were different in some of their kinetic properties, namely, their affinities for fructose and for cytochalasin B.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1041-1046
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• 2001

Solutions of fructose, glucose and sucrose were heated without catalyst at various temperature for different length of time. Changes in the formation of early caramelization product and browning intensity as well as pH of heated sugar solutions were determined. Reducing powers of caramelization products (CP) and their inhibitory effects on polyphenol oxidase (PPO) were also determined and their correlations were discussed. The early CP and browning intensity increased with temperature and time, in the order of heated fructose>sucrose>glucose solutions (p<0.005), while pH decreased. pHs of sugar solutions heated at 20$0^{\circ}C$ showed in the range of 3.32 ~ 3.50. Reducing power of CP as well as their inhibitory effect on PPO also increased with temperature and time, respectively. Among sugar solutions, reducing power showed the same trends as above at both 15$0^{\circ}C$ and 17$0^{\circ}C$ (p<0.001). However, those of heated fructose solutions were the highest in the early stage, while those of heated sucrose solutions were the highest in the final stage at 20$0^{\circ}C$. This is due to the difference in CP formed. Sucrose solution heated at 20$0^{\circ}C$ showed the highest inhibitory effect, reducing PPO activity by 34.6%. From these results, it is considered that the inhibitory effect of CP on PPO is partly related to their reducing power.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.575-581
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• 2000

Quality characteristics of kochujang prepared with appleand persimmon were investigated during 14 weeks of fermentation. The water activity decreased slightly during fermentation and was higher in kochujang (I) prepared with apple than in kochujang (II) prepared with presimmon. The reducing sugar contents increased from 10.95% in kochujang (I) and 10.30% in kochujang (II) to 16.68, 19.14% after 10 weeks of fermentation, respectively. The free sugar contents in kochujang (I) were maltose 10.55, glucose 8.47 and fructose, 3.02% after 12 weeks of fermentation. The free sugar content in kochujang (II) were maltose 10.55, glucose 21.65, glucose 8.71 and fructose 2.98 after 6 weeks of fermentation. The major free sugar in kochujang (I) and (II) was maltose. The organic acids detected in kochujangs were citric, malic, lactic and oxalic acids. The contents of citric acid and malic acid were higher than other acids in both kochujangs. The contents of total free amino acids were 187.59~420.94 mg% in kochujang (I) and 154.67~316.93 mg% in kochujang (II). The contents of aspartic acid, proline and glutamic acid were high in kochujang (I) and (II).