• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2004.06a
• /
• pp.215-218
• /
• 2004

Dextrans make up a class of polysaccharides that are D-glucans of various structures with contiguous $\alpha$-1longrightarrow6 ~6 glycosidic linkages in the main chains and $\alpha$-1longrightarrow2, $\alpha$-1longrightarrow3, or $\alpha$-1longrightarrow4 branch glycosidic linkages, depending on the specificity of the particular dextransucrase. Glucansucrases that catalyze glucans synthesis from sucrose. When other carbohydrates, in addition to sucrose, are present in the enzyme digest, the enzyme transfers glucose to the carbohydrate acceptors in the secondary reaction that diverts some of the glucose from incorporation into glucan. Many carbohydrate acceptors have been recognized and the products that result are dependent on the particular enzyme and the structure of the particular acceptor. Because of these unique catalytic characteristics, various dextransucrases have many important industrial and medical uses. To improve the understanding of their action mode and extend their applications, this study describes mechanism of glucan synthesis and potential industrial uses of dextransucrases, and our recent findings on the structural, functional organization and directed evolution of the glucansucrases to offer for designing glucansucrases with improved properties.

• Journal of Nutrition and Health
• /
• v.22 no.4
• /
• pp.266-274
• /
• 1989

The current study was undertaken to determine the effects of the ratios of dietary fat to carbohydrate and energy restriction on insulin sensitivity in the growing rats. Male rats weighting 80-90g were fed experimental diets for two weeks. Rats were killed and epiddymal adipose tissue were removed and sliced. Explants of adipose tissues were incubated for 2 hours in KRB(Krebs-Ringer bicarbonate) buffer containing various concentrations of human insulin and [U-14C]glucose. Insulin sensitivity was determined as glucose conversion to total lipids (lipogenesis) during 2 hr incubation. Exp't I : Effects of Ratios of Fat to Carbohydrate on Insulin Sensitivity. Eighteen male rats were fed 3 diets for 2 weeks. Diet 1 was low fat-high carbohydrate (4% soybean oil and 66.5% cornstarch) ; diet 2, medium fat-medium sarbohydrate(12% soybean oil and 58.5% cornstarch) ; diet 3, high fat-low carbohydrate (20% soybean oil and 50.5% cornstarch). Insulin sensitivity was higher in the order of LF-HC, MF-HC and HF-LC diet groups (p<0.05), i.e, lipogenesis was higher at all insuline concentration in the explants from rats fed LF-HC diet. However, thers was no significant difference in body weight gain and epididymal adipose tissue weight among treatments. Exp't II ; Effects of Energy Restriction on Insulin Sensitivity. Twelve rats were grouped into ad libitum feeding and restricted feeding(70% of ad libitum). The experimental diet was medium fat-medium carbohydrat diet as used in the Exp't I. Restricted feeding group tended to show higher insulin sensitivity compared to ad libitum group. However, there was no statistical difference between two groups. As expected, body weight gain and epididymal adipose tissue were higher in the ad libitum group. In summary, the resutls of the current study showed that the epididymal adipose tissue taken from the rats fed low fat-high carbohydrate diet showed higher insulin sensitivity compared to those fed high fat-low carbohydrate, and that resticted feeding tended to elevate insulin sensitivity in these tissues.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.9
• /
• pp.1187-1188
• /
• 2002

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.11
• /
• pp.1575-1589
• /
• 2017

Objective: This study was conducted to determine molecular structures related to carbohydrates and lipid in alfalfa hay cut at early bud, late bud and early flower and in the afternoon and next morning using Fourier transform infrared spectroscopy (FT/IR) and to determine their relationship with alfalfa hay nutrient profile and availability in ruminants. Methods: Chemical composition analysis, carbohydrate fractionation, in situ ruminal degradability, and DVE/OEB model were used to measure nutrient profile and availability of alfalfa hay. Univariate analysis, hierarchical cluster analysis (CLA) and principal components analysis (PCA) were conducted to identify FT/IR spectra differences. Results: The FT/IR non-structural carbohydrate (NSCHO) to total carbohydrates and NSCHO to structural carbohydrate ratios decreased (p<0.05), while lignin to NSCHO and lipid CH3 symmetric to CH2 symmetric ratios increased with advancing maturity (p<0.05). The FT/IR spectra related to structural carbohydrates, lignin and lipids were distinguished for alfalfa hay at three maturities by PCA and CLA, while FT/IR molecular structures related to carbohydrates and lipids were similar between alfalfa hay cut in the morning and afternoon when analyzed by PCA and CLA analysis. Positive correlations were found for FT/IR NSCHO to total carbohydrate and NSCHO to structural carbohydrate ratios with non-fiber carbohydrate (by wet chemistry), ruminal fast and intermediately degradable carbohydrate fractions and total ruminal degradability of carbohydrates and predicted intestinal nutrient availability in dairy cows ($r{\geq}0.60$; p<0.05) whereas FT/IR lignin to NSCHO and CH3 to CH2 symmetric stretching ratio had negative correlation with predicted ruminal and intestinal nutrient availability of alfalfa hay in dairy cows ($r{\geq}-0.60$; p<0.05). Conclusion: FT/IR carbohydrate and lipid molecular structures in alfalfa hay changed with advancing maturity from early bud to early flower, but not during the day, and these molecular structures correlated with predicted nutrient supply of alfalfa hay in ruminants.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.4
• /
• pp.556-567
• /
• 2020

Objective: To improve the utility of native grass resources as feed in China, we investigated the dynamics of protein and carbohydrate fractions among Inner Mongolian native grasses, during ensiling and the aerobic stage, using the Cornell Net Carbohydrate and Protein System. Methods: Silages were prepared without or with lactic acid bacteria (LAB) inoculant. We analyzed the protein and carbohydrate fractions and fermentation quality of silages at 0, 5, 15, 20, 30, and 60 d of ensiling, and the stability at 0.5, 2, 5, and 10 d during the aerobic stage. Results: Inner Mongolian native grass contained 10.8% crude protein (CP) and 3.6% water-soluble carbohydrates (WSC) on a dry matter basis. During ensiling, pH and CP and WSC content decreased (p<0.05), whereas lactic acid and ammonia nitrogen (N) content increased (p<0.05). Non-protein N (PA) content increased significantly, whereas rapidly degraded true protein (PB₁), intermediately degraded true protein (PB₂), total carbohydrate (CHO), sugars (CA), starch (CB₁), and degradable cell wall carbohydrate (CB₂) content decreased during ensiling (p<0.05). At 30 d of ensiling, control and LAB-treated silages were well preserved and had lower pH (<4.2) and ammonia-N content (<0.4 g/kg of fresh matter [FM]) and higher lactic acid content (>1.0% of FM). During the aerobic stage, CP, extract ether, WSC, lactic acid, acetic acid, PB₁, PB₂, true protein degraded slowly (PB₃), CHO, CA, CB₁, and CB₂ content decreased significantly in all silages, whereas pH, ammonia-N, PA, and bound true protein (PC) content increased significantly. Conclusion: Control and LAB-treated silages produced similar results in terms of fermentation quality, aerobic stability, and protein and carbohydrate fractions. Inner Mongolian native grass produced good silage, nutrients were preserved during ensiling and protein and carbohydrate losses largely occurred during the aerobic stage.

• Journal of the Korean Society of Food Culture
• /
• v.22 no.1
• /
• pp.157-165
• /
• 2007

This study was designed to evaluate the effects of fructose(F) or sucrose(S) and guar gum intake on carbohydrate and lipid metabolism in 15-week-old male Goto-Kakizaki(GK) rats. Fifty rats were randomly assigned to 5 groups which were different in carbohydrate(25% of carbohydrate) and fiber(5% w/w) sources. The carbohydrate(CHO) sources of each group were comstarch(control group, 100% of CHO), fructose with cellulose(F), fructose with guar gum(FG), sucrose with cellulose(S), and sucrose with guar gum(SG). Each group was fed exterimental diet for 4 weeks. We measured food intake, body weight gain, adipose tissues weight and organs weight. We conducted oral glucose tolerance test(OGTT) and measured plasma insulin concentration to examine carbohydrate metabolism. To evaluate lipid metabolism, we measured the lipid profile of plasma, liver and feces. Food intake and weight gain of FG or SG groups tended to be less than those of F or S groups. Perirenal and epididymal fat pad weights of SG group were significantly lower than those of S group and those of FG group tended to be lower than those of F group. In OGTT, blood glucose values of F or S groups were significantly higher than those of C group, and FG or SG groups tended to be lower than those of F or S groups during the experimental time. The area under the curve(AUC) of C group was significantly highest among the groups, AUC and plasma insulin concentration of FG or SG groups tended to be lower than those of F or S groups. Plasma and hepatic triglyceride (TG) of FG and SG groups were significantly lower than those of F and S groups, plasma and hepatic total lipid(TL) and total cholesterol(TC) of FG and SG groups tended to be lower than those of F and S groups. Fecal TL, TG and TC of FG or SG groups tended to be higher than those of F and S groups. In conclusion, intake of guar gum should improve carbohydrate and lipid metabolism in partial substitution of fructose or sucrose for cornstarch in GK rats.

• BMB Reports
• /
• v.29 no.3
• /
• pp.266-271
• /
• 1996

A recombinant human erythropoietin (EPO), expressed in Chinese hamster ovary (CHO) cells, is glycosylated at Asn 24, Asn 38, Asn 83, and Ser 126. After release of the N-linked carbohydrate chains by $peptide-N^{4}-(N-acetyl-{\beta}-glucosaminyl)$ asparagine amidase F, the oligosaccharides were analyzed by FACE (Fluorophore-Assisted Carbohydrate Electrophoresis). The O-linked carbohydrate chain was separated by hydrazine, and analyzed by FACE. The monosacccharide composition of recombinant EPO showed man nose, fucose, galactose, N-acetylglucosamine, N-acetylneuraminic acid, and a trace of N-acetylgalactosamine, which are typical monosaccharides in the glycoproteins from the CHO cell. Sequences of N-linked and O-linked oligosaccharides were determined. The structure and composition of oligosaccharides attached to recombinant human EPO, expressed in the CHO cell, are identical to the reported oligosaccharide structure in human EPO isolated from urine.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.43 no.4
• /
• pp.273-278
• /
• 1998

Carbohydrate metabolism and partitioning are dependent on relationships between sources and sinks which can be affected by rates of photosynthesis and respiration. Fructan, the major form of stored carbohydrate in tall fescue (festuca arundineacea Schreb.), changes in concentration during growth and in response to the environment. Objectives of this study were i) to examine the content and the composition of carbohydrates in five tissues (mature leaf blade, immature leaf blade, leaf elongation zone, terminal meristem, and root tips) of two tall fescue genotypes, one with high yield per tiller (HYT) and one with low yield per tiller (LYT), and ii) to compare the reserved and utilized carbohydrates among above five different tissues, particularly between the leaf elongation zone and root tips. The established vegetative tillers of the HYT and LYT genotypes were grown in a controlled-environment growth chamber. Water-soluble carbohydrate (WSC) in the leaf elongation zone was about 22% of dry weight in the HYT and about 19% in the LYT genotype. The root tip also had high WSC, about 12% of dry weight in the HYT and 6% in the LYT genotype. Hexoses and sucrose were the major components of total WSC in all tissues except the leaf elongation zone. The growing tissues (sinks), i.e., the leaf elongation zone and root tip, had a high proportion of low degree of polymerization fructan, i.e., 3 to 8 hexose units.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.22 no.3
• /
• pp.155-161
• /
• 2016

As one of traditional packaging materials, paper and paperboard are being more popular and beneficial thanks to their environmental sustainability and have been widely used in packaging applications, from light weight infusible tissue for tea/coffee bags to heavy duty boards for the distribution. Papermakers have to design the products having a desired customized function with their paper machine. Globally, the use of filler and pigment in papermaking is now a very common practice to meet the needs of customers. Many benefits can be achieved as a result of filler addition, which mainly includes cost and energy savings. The replacement of traditional mineral fillers and pigments with biodegradable and renewable carbohydrate polymers is a very interesting and promising research topic due to the concern of environmental impact. In this review paper, the use of traditional and novel carbohydrate fillers and pigments in cellulosic paper is highlighted. It is noteworthy that there are still some challenges and technical barriers associated with the use of these organic materials in point of structural stabilities and manufacturing costs, although most of them are available in market as the commercialized products. With the emerging nanotechnologies, it is believed that the use of carbohydrate-based filler and pigment for papermaking will increase and bring technical advantages to industry.

• Journal of Nutrition and Health
• /
• v.6 no.1
• /
• pp.31-38
• /
• 1973

The effect of dietary condition on the acethylcholine and chotinesterase activity in the brain was observed. Rats weighting $120{\sim}130\;gm$ was fed on diets deprived of protein, carbohydrate and lipid, respectively. Experimental terms was devided into 3, 7 and 15 days. The results are summarized as follows: 1. The lipid free diet makes greater contribution to the gain of body weight than the carbohydrate free and protein free diet. 2. The acethylcholine in the protein free diet group is reduced after 7 days and that in the carbohydrate free diet, after 3 days. 3. The cholinesterase activity shows continuing decrease after 3 days by protein free diet, and the other diet groups appear temporal decrease at 7 days and increase, at 15 days. 4. The relation of acethylcholine, and cholinesterase is similar to each other except that of the carbohydrate diet. From the above results, the conclusions are obtained that the protein free diet makes the acethylcholine and cholinesterase activity lower, and the carbohydrate free diet, acethylcholine lower.