• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.493-499
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• 1996

Lactan gum produced by Rahnella aquatilis is a high viscous, anionic polysaccharide and has shear thinning behaviour. Lactan gum yield and cencentration was greater on disaccharide such as lactose and sucrose than on monosaccharides such as glucose and galactose. When initial carbon source concentration was 45g/l of sucrose of lactose, the microorgnisms produced 28 g/l and 27 g/l of lactan, respectively with a yield more than 60%. $\beta$-Galactosidase, hydrolyzing lactose into galactose and glucose, was induced by lactose or galactose. When initial corbon source was 45 g/l of mixed carbon I (glucose:galactose=1:1), lactan gum concentaration was higher than that from 45 g/l of monosaccharide (glucose pf galactose) but was similar to the result from 45 g/l of lactose. Therefore, lactose hydrolysis reaction by $\beta$-galactosidase does not seem to be a rate determining step in lactan gum biosynthesis. When initial carbon source was 45 g/l of mixed carbon II (glucose:fructose=1:1). total carbon source consumption rate was slower than that from sucrose, but glucose consumption rate was faster than that from fructose.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.293-297
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• 2018

Controlling the residual glucose concentration is important for improving productivity in $\text\tiny{L}$-threonine fermentation. In this study, we developed a procedure to automatically control the feeding quantity of glucose solution as a function of ammonia-water consumption rate. The feeding ratio ($R_{C/N}$) of glucose and ammonia water was predetermined via a stoichiometric approach, on the basis of glucose-ammonia water consumption rates. In a 5-L fermenter, 102 g/l $\text\tiny{L}$-threonine was obtained using our glucose-ammonia water combined feeding strategy, which was then successfully applied in a 500-L fermenter (89 g/l). Therefore, we conclude that an automatic combination feeding strategy is suitable for improving $\text\tiny{L}$-threonine production.

• Molecules and Cells
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• v.23 no.3
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• pp.272-279
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• 2007

The maintenance of normal blood glucose levels at rest and during exercise is critical. The maintenance of blood glucose homeostasis depends on the coordination and integration of several physiological systems, including the sympathetic nervous system and the endocrine system. During prolonged exercise increased demand for glucose by contracting muscle causes to increase glucose uptake to working skeletal muscle. Increase in glucose uptake by working skeletal muscle during prolonged exercise is due to an increase in the translocation of insulin and contraction sensitive glucose transporter-4 (GLUT4) proteins to the plasma membrane. However, normal blood glucose level can be maintained by the augmentation of glucose production and release through the stimulation of liver glycogen breakdown, and the stimulation of the synthesis of glucose from other substances, and by the mobilization of other fuels that may serve as alternatives. Both feedback and feedforward mechanisms allow glycemia to be controlled during exercise. This review focuses on factors that control blood glucose homeostasis during prolonged exercise.

• KSBB Journal
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• v.15 no.5
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• pp.482-488
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• 2000

The Fab fraction of PDC-E2 specific human monoclonal antibody was produced using recombinant E. coli, and the effects of glucose and acetate were investigated to develop an optimal strategy for recombinant human antibody production. Higher glucose concentration in the culture media resulted inn higher cell growth and glucose consumption rate, which in turn resulted in an increased acetate production rate. When glucose was depleted, cells began to consume acetate as an energy source, and this consumption rate depended on the glucose concentration. When the residual glucose concentration was high, the accumulation of acetate was accelerated due to an increase in the acetate production rate and a decrease in the acetate consumption rate. Futhermore, it was found that a high accumulation of acetate, accompanied by a high glucose concentration, inhibited human antibody formation; the critical acetate concentration was $0.6g/\ell$. During production, a high glucose concentration enhanced cell growth, but inhibited antibody formation due to catabolic repression. Therefore, it is important to keep the concentration of both glucose and acetate as low as possible to increase antibody production after induction. Accordingly, it is important to accurately control the concentration of glucose and acetate in the culture media to obtain high cell densities and high productivity levels of recombinant human antibody.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.560-564
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• 2013

${\small{D}}$-Ribose is a value-added five-carbon sugar used for riboflavin production. To investigate the effects of oxygen supply and mixed sugar concentration on microbial production of ${\small{D}}$-ribose, a transketolase-deficient Bacillus subtilis SPK1 was cultured batch-wise using xylose and glucose. A change of agitation speed from 300 rpm to 600 rpm at 1 vvm of air supply increased both the xylose consumption rate and ${\small{D}}$-ribose production rate. Because the sum of the specific consumption rates for xylose and glucose was similar at all agitation speeds, metabolic preferences between xylose and glucose might depend on oxygen supply. Although B. subtilis SPK1 can take up xylose and glucose by the active transport mechanism, a high initial concentration of xylose and glucose was not beneficial for high ${\small{D}}$-ribose production.

• Journal of Preventive Medicine and Public Health
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• v.44 no.2
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• pp.93-100
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• 2011

Objectives: This study was performed to identify the socioeconomic factors, health behavior factors and dietary patterns that have an influence on the fasting blood glucose in adults. Methods: This study used data collected from the 2007, 2008, 2009 Korea National Health and Nutrition Examination Survey. The final sample included 4163 subjects who were 30-59 years old and who had completed the necessary health examinations, the health behaviors survey and nutrition survey. Results: Eleven dietary patterns emerged from the factor analysis with different factor loading. After controlling for potential confounders, multiple regression analysis of the dietary patterns showed that 'fruits', 'alcohols', and 'starchy foods' affected the fasting blood. Lower consumption of 'fruits' and higher consumption of 'alcohols' and 'starch foods' were significantly associated only with an increased risk of high blood glucose. Conclusions: In the light of the results of this study, it appears pretty likely that the risk of developing high blood glucose can be reduced by changing a person's dietary patterns.

• Nutrition Research and Practice
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• v.9 no.3
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• pp.262-267
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• 2015

BACKGROUND/OBJECTIVES: The primary objective of the treatment of diabetes mellitus is the attainment of glycemic control. Hyperglycemia increases oxidative stress which contributes to the progression of diabetic complications. Thus, the purpose of this study was to investigate the hypoglycemic and antioxidant effects of Daraesoon (Actinidia arguta shoot) in animal models of diabetes mellitus. MATERIALS/METHODS: Rats with streptozotocin-induced diabetes received an oral administration of a starch solution (1 g/kg) either with or without a 70% ethanol extract of Daraesoon (400 mg/kg) or acarbose (40 mg/kg) after an overnight fast and their postprandial blood glucose levels were measured. Five-week-old C57BL/6J mice were fed either a basal or high-fat/high-sucrose (HFHS) diet with or without Daraesoon extract (0.4%) or acarbose (0.04%) for 12 weeks after 1 week of adaptation to determine the effects of the chronic consumption of Daraesoon on fasting hyperglycemia and antioxidant status. RESULTS: Compared to the control group, rats that received Daraesoon extract (400 mg/kg) or acarbose (40 mg/kg) exhibited a significant reduction in the area under the postprandial glucose response curve after the oral ingestion of starch. Additionally, the long-term consumption of Daraesoon extract or acarbose significantly decreased serum glucose and insulin levels as well as small intestinal maltase activity in HFHS-fed mice. Furthermore, the consumption of Daraesoon extract significantly reduced thiobarbituric acid reactive substances and increased glutathione levels in the livers of HFHS-fed mice compared to HFHS-fed mice that did not ingest Daraesoon. CONCLUSIONS: Daraesoon effectively suppressed postprandial hyperglycemia via the inhibition of ${\alpha}$-glucosidase in STZ-induced diabetic rats. Chronic consumption of Daraesoon alleviated fasting hyperglycemia and oxidative stress in mice fed a HFHS diet.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1747-1756
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• 2013

The aim of this paper was to study the effect of spent medium recycle on Spodoptera exigua Se301 cell line proliferation, metabolism, and baculovirus production when grown in batch suspension cultures in Ex-Cell 420 serum-free medium. The results showed that the recycle of 20% of spent medium from a culture in mid-exponential growth phase improved growth relative to a control culture grown in fresh medium. Although both glucose and glutamine were still present at the end of the growth phase, glutamate was always completely exhausted. The pattern of the specific glucose and lactate consumption and production rates, as well as the specific glutamine and glutamate consumption rates, suggests a metabolic shift at spent medium recycle values of over 60%, with a decrease in the efficiency of glucose utilization and an increase in glutamate consumption to fuel energy metabolism. Baculovirus infection provoked a change in the metabolic pattern of Se301 cells, although a beneficial effect of spent medium recycle was also observed. Both growth rate and maximum viable cell density decreased relative to uninfected cultures. The efficiency of glucose utilization was dramatically reduced in those cultures containing the lowest percentages of spent medium, whereas glutamine and glutamate consumption was modulated, thereby suggesting that infected cells were devoted to virus replication, retaining their ability to incorporate the nutrients required to support viral replication. Recycle of 20% of spent medium increased baculovirus production by around 90%, thus showing the link between cell growth and baculovirus production.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.6
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• pp.571-578
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• 1999

This study evaluated the effects of PKC activation using phorbol 12-myristate 13-acetate (PMA) and PKC inhibition using the isoquinoline sulfomide derivative H-7 on hemodynamics and glucoregulation in the isolated perfused rat liver. Livers were isolated from fed male Holtzman rats and perfused with Krebs Ringer bicarbonate solution under a constant flow of 50 ml/min at $35^{\circ}C.$ Portal vein pressure, glucose and lactate concentrations in the medium and oxygen consumption rates were continuously monitored by a Grass polygraph, YSI glucose and lactate monitors, and a YSI oxygen monitor, respectively. PMA at concentration of 2 to 200 nM increased the portal vein pressure, glucose and lactate production, but decreased oxygen consumption rate in a dose-dependent fashion. H-7 $(200\;{\mu}M)$ attenuated PMA (50 nM)-induced vasoconstriction $(15.1{\pm}1.36\;vs\;10.56{\pm}1.17\;mmHg),$ glucose production rate $(91.3{\pm}6.15\;vs\;71.8{\pm}2.50\;{\mu}moles/g/hr),$ lactate production rate $(72.4{\pm}6.82\;vs\;53.6{\pm}4.82\;{\mu}moles/g/hr)$ and oxygen consumption rate $(33.7{\pm}1.41\;vs\;27.9{\pm}1.75\;{\mu}l/g/min).$ The effects of PMA were blocked either by addition of verapamil $(9\;{\mu}M)$ or perfusion with $Ca^{2+}-free$ KRB. These results suggest that the hemodynamic and glucoregulatory changes in the perfused rat liver are mediated by protein kinase C activation and require $Ca^{2+}$ influx from the extracellular fluid.

• Journal of Nutrition and Health
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• v.30 no.9
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• pp.1055-1060
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• 1997

The purpose of this study was to investigate the potential hypoglycemic effect of adlay diets when total fiber consumption was controlled in streptozotocin-induced diabetic rats. Forty eight rats were fed for 3 weeks with either controlled in streptozotocin -induced diabetic rats. Forty eight rats were fed for 3 weeks with either control diets or experimental diets : raw mille adlay (RMA) raw whole adlay(RWA) , steamed milled adlay(SMA) or roasted mille adlay(OMA). The composition of the AIN-76 diet was modified to ensure the same composition of protein, carbohydrate , rat, and fiber between the control diet and experimental diets. The concentrations of glucose , insulin, glycogen, and protein in plasma, liver, or skeletal muscle were compared . Compared to diabetic control rats, plasma postprandial glucose levels tended to be decreased in RMA, RWA, SMA and OMA rats until the 2nd week, but no difference was shown at the 3 rd week. There was no significant difference in insulin levels among those groups. After glucose loading, the plasma glucose level of SMA was lower than that of diabetic control rats throughout 2 hrs. Liver glycogen was lower than control values in RMA and RWA rats and not different in SMA and OMA rats. The muscle protein level of RMA, RWA, SMA, and OMA rats tended to be lower than in diabetic control rats. There was no significant difference in muscle glycogen among groups. These results suggest that the hypoglycemic effect of an adlay diet is not significant when the amount of total fiber consumption is controlled.