Small Amounts Of Glucose Research Articles

Anticoagulant properties of a sulfated galactan preparation from a marine green alga, Codiumcylindricum

An anticoagulant was isolated from a marine green alga, Codium cylindricum. The anticoagulant was composed mainly of galactose with a small amount of glucose, and was highly sulfated (13.1% as SO 3 Na). The anticoagulant properties of the purified anticoagulant were compared with that of heparin by assays of activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) using normal human plasma. The anticoagulant showed similar activities with heparin, however, weaker than heparin. On the other hand, the anticoagulant did not affect PT even at the concentration at which APTT and TT were strongly prolonged. The anticoagulant did not potentiate antithrombin III (AT III) and heparin cofactor II (HC II), thus the anticoagulant mechanism would be different from that of other anticoagulants isolated so far from the genus Codium.

Purification and some properties of a novel raw starch-digesting amylase fromAspergillus carbonarius

A medium was developed to obtain the maximum yield of raw starch-digesting amylase from Aspergillus carbonarius (Bainier) Thom IMI 366159 in submerged culture with raw starch as the sole carbon source. The amylase was purified to apparent homogeneity by sucrose concentration and ion exchange chromatography on S- and Q-Sepharose (fast flow) columns. SDS-PAGE revealed two migrating protein bands corresponding to relative molecular masses of 31.6 and 32 KDa. The enzyme was optimally active at pH 6.0–7.0 and 40 °C, was uninfluenced across a relatively broad pH range of 3.0–9.0 and retained over 85% activity between 30 and 80 °C after 20 min incubation. The enzyme was strongly activated by Co2+ and only slightly by Fe2+, while Ca2+, Hg2+, EDTA and N-bromosuccinamide elicited significant repression of the enzyme activity. The enzyme hydrolysed amylopectin (Km 0.194 mg ml −1), glycogen (Km 0.215 mg ml −1), pullulan (Km 0.238 mg ml −1), amylose (Km 0.256 mg ml −1) and raw potato starch (Km 0.260 mg ml −1), forming predominantly maltose and relatively smaller amounts of glucose. © 2000 Society of Chemical Industry

Purification and biological activity of acidic polysaccharide from leaves of Thymus vulgaris L.

Polysaccharides are involved in biological responses and can activate complement system, which plays an important role in primary host defense mechanisms. We investigated anticomplementary activities from spice plants and selected thyme (Thymus vulgaris L.) as a potent complementary activator. Acidic polysaccharide (TV-3-IIIA-IIa) purified from the hot-water extract of thyme leaves by DEAE-Toyopearl 650C, Butyl-Toyopearl 650M and Sepharose CL-6B column chromatography and preparative HPLC. The purified polysaccharide, TV-3-IIIA-IIa showed potent anticomplementary activity via classical and alternative pathway with the increase proportional to dosage. TV-3-IIIA-IIa seemed to be a homogenous polymer from the results of HPLC and its molecular mass was estimated as 180 kDa. TV-3-IIIA-IIa mainly consisted of galacturonic acid (44.8 mol%), glucuronic acid (16.7 mol%), arabinose (11.1 mol%), rhamnose (9.2 mol%), galactose (8.9 mol%) and small amounts of glucose, xylose, mannose and fucose. By methylation analysis and reactivity to beta-glucosyl Yariv reagent, TV-3-IIIA-IIa was assumed to contain small amounts of type II arabinogalactan and large amounts of pectin-like polysaccharides in the structure. Based upon these results, TV-3-IIIA-IIa was suggested to be a complement activator.

Purification and Characterization of an Endo-cellulase from Acremonium cellulolyticus.

An endo-cellulase from a commercial cellulase preparation of a filamentous fungus Acremonium cellulolyticus was separated and extensively purified to essential homogeneity by using consecutive column chromatographies of QAE-Toyopearl 550C, DEAE-Toyopearl 650S, Butyl-Toyopearl 650M and Bio-Gel P-100, and was designated as cellulase IV The purified enzyme was homoge-neous on both Native- and SDS-PAGE, and was completely free from β-glucosidase. The enzyme showed high specific activity for CMC and an extremely low specific activity for Avicel (a mi-crocrystalline cellulose powder), 106 and 0.08 U/mg of protein, respectively. The molecular mass of the enzyme was estimated to be about 38 kDa by SDS-PAGE. The enzyme was an acidic protein with a pI value of≤3.4. The N-terminal amino acid sequence from the 2nd up to the 27th residue of the purified cellulase was Gln-Ala-Ser-(Cys)-Phe-Glu-Trp-Phe-Gly-Ser-Asn-Glu-Ser-Gly-Ala-Glu-Phe-Gly-Ser-Gly-Asn-Ile-Pro-Gly-Val-Glu-. The optimum pH and temperature were 4.0 and 60-C, respectively. The enzyme was completely stable over the range of pH 5.0-12.0 at 4-C for 24 h and at temperatures below 50-C. Cellulase IV was characterized as a medium endo -type cellulase on the basis of its action on CMC and cellooligosaccharides. The enzyme was completely inhibited by 5 mM Hg2+, Fe3+ and KMnO4. Cellulase IV split various cellulosic substrates to pro-duce predominant cellobiose and a small amount of glucose as the final hydrolysis products.

Purification and Properties of Two Endo-cellulases from Acremonium cellulolyticus.

Two distinct endo-cellulase components derived from Acremonium cellulase, a commercial cellulase preparation from Acremonium cellulolyticus, were extensively purified by consecutive column chromatography and designated as cellulase III-A and cellulase III-B. Cellulases III-A and III-B were each homogeneous on both Native- and SDS-PAGE, and were completely free from β-glucosidase. The molecular mass (SDS-PAGE) and pI Tvalues of cellulases IIIV-A and III-B were 58 kDa and 4.6, and 49 kDa and 4.2, respectively. Both enzymes contained 14-16% carbohydrates (as glucose). The N-terminal amino acid sequences from the 2nd up to the 20th residue of bothenzymes were determined by Edman degradation. Some enzymatic properties of the purified cellulases were investigated. The optimum pH and temperature for cellulases III-A and III-B were pH 5.5 and 55°C, and pH 5.5 and 65°C, respectively. Cellulases III-A and III-B were completely stable over the range of pH 4.2-8.0 at 4°C for 24 h and at temperatures below 55°C, and pH 3.3-7.8 and below 60°C, respectively. Cellulases III-A and III-B retained 25 and 88% of the original CMC-saccharification activities, respectively, after heating at 70°C for 10 min. The hydrolysis of CMC by cellulase III-B was more endo-lytic than that by cellulase III-A. Both enzymes splitvarious soluble and insoluble substrates to produce predominant cellobiose and a small amount of glucose as the final hydrolysis products.

The composition of maturing Omani dates

The composition of two varieties of Omani dates, fard and khalas, was determined as maturity progressed. Free sugars and dietary fibre content were examined in detail. High-performance liquid chromatography (HPLC) of the extracts showed that at the early green stage (Arabic kimri), dates contained small amounts of glucose and fructose. At the intermediate yellow (khalal) and red (rutab) stages, large amounts (500–565 g kg−1 dry weight) of sucrose had accumulated, but no additional glucose or fructose was detected. At the final mature (tamar) stage, all sucrose was converted to glucose and fructose (>800 g kg−1 dry weight). Dietary fibre, determined as non-starch polysaccharides (NSPs) by gas chromatography (GC), decreased from 250 g kg−1 (kimri) to 50 g kg−1 (tamar) on a dry weight basis. The principal monomers of NSPs were glucose, galactose, xylose, mannose, arabinose and rhamnose. On a dry weight basis, pectin, protein and ash contents decreased as the dates matured. On a fresh weight basis, changes in NSPs, pectin, protein and ash could be attributed to loss of moisture and the accumulation of sucrose initially, or of invert sugar later as maturation progressed. © 1999 Society of Chemical Industry

Perspectives on ruminant nutrition and metabolism. II. Metabolism in ruminant tissues

The discovery of the dominance of short-chain fatty acids as energy sources in the 1940s and 1950s, as discussed in part I of this review (Annison & Bryden, 1998) led to uncertainties concerning the interrelationships of glucose and acetate in ruminant metabolism. These were resolved in the following decade largely by use of 14C-labelled substrates. Although only small amounts of glucose are absorbed in most dietary situations, glucose availability to ruminant tissues as measured by isotope dilution was shown to be substantial, indicating that gluconeogenesis is a major metabolic activity in both fed and fasted states. Studies with 14C-labelled glucose and acetate revealed that in contrast to non-ruminants, acetate and not glucose is the major precursor of long-chain fatty acids in ruminant tissues. Interest in the measurement of energy metabolism in livestock grew rapidly from the 1950s. Most laboratories adopted indirect calorimetry and precise measurements of the energy expenditure of ruminants contributed to the development of new feeding systems. More recently, alternative approaches to the measurement of energy expenditure have included the use of NMR spectroscopy, isotope dilution and the application of the Fick principle to measure O2 consumption in the whole animal and in defined tissues. The refinement of the classical arterio-venous difference procedure in the study of mammary gland metabolism in the 1960s, particularly when combined with isotope dilution, encouraged the use of these methods to generate quantitative data on the metabolism of a range of defined tissues. The recent introduction of new methods for the continuous monitoring of both blood flow and blood O2 content has greatly increased the precision and scope of arterio-venous difference measurements. The impact of data produced by these and other quantitative procedures on current knowledge of the metabolism of glucose, short-chain fatty acids and lipids, and on N metabolism, is outlined. The role of the portal-drained viscera and liver in N metabolism is discussed in relation to data obtained by the use of multi-catheterized animals. Protein turnover, and the impact of stress (physical, social and disease related) on protein metabolism have been reviewed. The growth of knowledge of mammary gland metabolism and milk synthesis since the first quantitative studies in the 1960s has been charted. Recent findings on the regulation of amino acid uptake and utilization by the mammary gland, and on the control of milk secretion, are of particular interest and importance.

Improving ecological fitness and environmental stress tolerance of the biocontrol yeast Candida sake by manipulation of intracellular sugar alcohol and sugar content

Candida sake was cultured on nutrient yeast dextrose broth, which was diluted and/or modified by the addition of either glycerol, glucose to 0.96 or trehalose to 0.97 water activity ( a w ) to modify endogenous sugar alcohol and sugar content. Sugar alcohols (glycerol, erythritol, arabitol and mannitol) and sugars (trehalose and glucose) were extracted from the yeast cells and quantified using HPLC. Total polyol and sugar content varied significantly between treatments. The total intracellular concentrations in NYDB medium were significantly increased in NYDB + glucose media. The major intracellular polyols/sugars in cells grown on unmodified NYDB were arabitol, trehalose and glucose with small amounts of glycerol and erythritol. This was changed by reducing a w of the growth medium, particularly with glucose or glycerol. The major polyols in C. sake cells grown on glucose-modified media were arabitol and the low mol wt polyol glycerol, with smaller amounts of glucose. In glycerol-amended full strength normal and diluted media, glycerol was the major intracellular polyol with lower amounts of the other polyols and sugars. The viability of the yeast cells with modified polyols/sugars was significantly improved at lowered a w level (0.935 and 0.95) when compared to unmodified yeast cells. Improvements in water stress tolerance was better in yeast cells grown for 48 than 24 h, especially in those from NYDB modified with either glucose, glycerol or trehalose. Such modifications of endogenous reserves were also shown to preserve or improve the biocontrol potential of the yeast against Penicillium expansum rot of apples. Thus physiological manipulation of intracellular polyol and sugar content may provide a means for developing biocontrol agents with improved ecological fitness in field environments.

Degradation of Konjac Glucomannan by Enzymes in Human Feces and Formation of Short-Chain Fatty Acids by Intestinal Anaerobic Bacteria.

Konjac (konnyaku) glucomannan was examined for its degradation in human intestines and fermentation products. The konjac glucomannan was degraded almost 100% by soluble enzymes in human feces to give 4-O-beta-D-mannopyranosyl-D-mannopyranose (beta-1,4-D-mannobiose), 4-O-beta-D-glucopyranosyl-D-glucopyranose (cellobiose), 4-O-beta-D-glucopyranosyl-D-mannopyranose, and small amounts of glucose and mannose. These three disaccharides were further degraded by a cell-associated enzyme(s) to glucose or mannose, or to both. Konjac glucomannan underwent fermentation by intestinal anaerobic bacteria and produced formic acid, acetic acid, propionic acid, and 1-butyric acid. These fatty acids were different in their proportions among test subjects, their total amounts ranging from 17.1% to 48.8% of the initial konjac glucomannan.

Exopolysaccharide Production and Texture-Promoting Abilities of Mixed-Strain Starter Cultures in Yogurt Production

An exopolysaccharide-producing strain of Lactobacillus delbrueckii ssp. bulgaricus (CNRZ 1187) and two colonial white and pink variants were grown in skim milk in association with a strain of Streptococcus thermophilus (CNRZ 389) that did not produce exopolysaccharide to assess the effects of associative growth on exopolysaccharide formation. After 10h of fermentation, viscosity (380 mPa.s) was highest with the parental strain CNRZ 1187 in the mixed-strain starter, the lowest (220 mPa.s) with the mixed-strain starter containing the white variant and S. thermophilus CNRZ 389, and intermediate (290 mPa.s) with the mixed-strain starter containing the pink variant and S. thermophilus CNRZ 389. Viscosities of the milks with exopolysaccharide-producing strains decreased after mechanical stirring, but values remained higher (170 to 230 mPa.s) than those obtained with nonproducing strains (70 mPa.s). The mixed-strain starter composed of the white colonies of L. delbrueckii spp. bulgaricus and S. thermophilus produced the highest amount of exopolysaccharide (240 mg/L), and the mixed-strain starter containing the parental strain CNRZ 1187 produced the lowest amount (110 mg/L) of exopolysaccharide. The exopolysaccharide production from the mixed-strain starter containing the white and pink L. delbrueckii ssp. bulgaricus colonies began earlier and was higher after 3h of fermentation than that from the starter containing the parental L. delbrueckii ssp. bulgaricus strain. Production of exopolysaccharide from the latter approached the maximum in the beginning of the stationary growth phase; production from the mixed-strain starter with the pink and white variants continued during the early stationary growth phase. The exopolysaccharide contained mainly galactose with small amounts of glucose and rhamnose. The monosaccharide composition of the exopolysaccharide changed during the exponential growth phase (6h) and remained stable thereafter.

Total nutritional manipulation in humans: report of acancer patient

We report here on a patient requiring home total parenteral nutrition (TPN) for a huge intra-abdominaldesmoid associated with chronic small bowel pseudo-obstruction who was kept on a special lipid-based calorie regimen for 5 months. The rationale was to attempt to feed the host with a minimal stimulation of tumour growth by using lipid as caloric substrate instead of glucose which is utilized by the tumour. Gluconeogenesis was tentatively inhibited at the level of phosphoenolpyruvate-carboxy-kinase through the oral intake of hydrazine sulphate. The regimen consisted of 28 non-protein lipid Kcal/kg/day plus 1.5 g amino acid per kg/day. Only a small amount of glucose (approx. 40 g/day) was allowed. Tolerance to the regimen was good and body weight maintained. Liver enzymes remained within the normal range and liver sonography was normal throughout the 5 months' therapy and there were no episodes of symptomatic hypoglycaemia. The tumour volume did not substantially change.

Application of glucose at low concentrations to grass swards in waste-derived compost can significantly increase long-term yields

Carbohydrates have a range of effects on soil, dependent on the frequency and concentration of the application. Small quantities of glucose have the effect of accelerating the removal of available N (NH4+, NO3−) through incorporation into the bodies of microorganisms. This reduces plant growth (Jenkinson, 1985), the rate of which depends largely on the presence of available N (Addiscott et al., 1991). However, in theory, if appropriate soil glucose concentrations are maintained, asymbiotic N2-fixation will occur, supplying extra nitrogen nutrition to plants over an extended period. Here, it is demonstrated that the use of 0.028 M glucose and an appropriate source of N2-fixing bacteria (green waste-derived compost) can result in increased grass dry matter yields of over 50% in a glasshouse experiment.

Continuous production of non-alcohol beer by immobilized yeast at low temperature

A system for production of non-alcohol beer is described. A limited fermentation is carried out with immobilized cells ofSaccharomyces cerevisiae in a packed bed reactor. In the reactor, combined stress factors such as low temperature (2–4°C) and anaerobic conditions limit cell metabolism. Of the available sugars only a small amount of glucose is metabolized, resulting in low concentrations of ethanol (<0.08%). The absence of oxygen affects the redox balance of the yeast cell, and thus stimulates formation of esters and higher alcohols. Products are formed by reduction of wort aldehydes, as well as reduction of intracellular metabolites. Despite the stress conditions, biomass increases during prolonged production periods. In batch experiments,S. cerevisiae strain W34 grows at low temperatures and a mininum growth temperature of −2 °C was found, indicating that a further reduction of temperature during production will not inhibit growth. The characteristics of the system allow its use in very different applications. Potential applications of the immobilized system are discussed.

Depolymerization of Molten‐Moisturized‐Starch Molecules by Shearing‐Force under High Temperature

AbstractPotato, corn and wheat starch containing 20% moisture were treated with a flow tester under heated and heated‐sheared conditions. Then heated and heated‐sheared starch specimens were prepared from three kinds of intact starches. Small amount of glucose was detected in water‐soluble fractions of heated and heated‐sheared specimens in spite of almost no detection in intact starches. By viscometry, the viscometric molecular weight of intact potato, intact corn and intact wheat starch with 20% moisture were 104kDa, 527kDa and 605kDa, respectively. While for heated specimens their molecular weights were depolymerized into 986kDa, 34kDa and 511kDa, respectively, and for heated‐sheared specimens, they were significantly depolymerized into 539kDa, 169kDa and 279kDa, respectively. Those facts were also supported from gel filtration profiles. As the results from glucose formation, viscometric molecular‐weight depolymerization and gelfiltration profiles, the considerable depolymerization in melt starchmolecules is yielded by the physical shearing‐force on starch melt despite starch varieties.

Effect of glucose on sporulation and extracellular amylase production byClostridium perfringens type A in a defined medium

The effect of glucose and other sugars on sporulation and extracellular amylase production byClostridium perfringens NCTC 8679 type A in a defined medium was studied. Cells grown in the presence of glucose and mannose yielded the highest levels of amylase activity, while disaccharides such as lactose, maltose, and sucrose resulted in moderate amylase production. Little amylase activity was detected in the medium in the presence of ribose or galactose. The concentration of each sugar resulting in highest amylase production was between 6 and 10mm except for fructose (25mm). Levels of heat-resistant spores decreased as sugar concentrations increased. The addition of even small amounts of glucose to the medium before exponential growth suppressed sporulation but maximized amylase activity. The addition of glucose after the initiation of sporulation did not inhibit spore formation. However, its addition to 3-h amylase-producing cells did inhibit subsequent sporulation but promoted the continued excretion of amylase. The different response to glucose between sporulating cells and amylase-producing cells suggests that the mechanisms of catabolite repression of extracellular amylase production and sporulation are distinct in this strain ofC. perfringens.

Study of the carbohydrate fraction of the principal varieties of Tarragona hazelnuts ( Corylus avellana L.)

The amounts of sugars, starch and fibre were determined in 22 samples of the main varieties of Tarragona hazelnuts (Negret, Pauetet, Gironell, Culplà, Morell and Grifoll). The main sugar identified by gas chromatography was sucrose, with small amounts of glucose, fructose, myo-inositol and raffinose. The typical mountain varieties (Culplà and Morell) showed the highest sucrose contents (7.90 g/100 g and 6.80 g/100 g of defatted material, d.m.). The amount of reducing sugars exceeded 0.40 g/100 g d.m. in only one sample. All varieties had similar contents of starch, neutral detergent fibre (NDF) and acid detergent fibre (ADF).

Purification and Some Properties of Dextrin Dextranase from Acetobacter capsulatus ATCC 11894

Dextrin dextranase (EC 2.4.1.2), which synthesizes dextran from maltooligosaccharides, was purified from Acetobacter capsulatus ATCCl1894 cells by n-butanol extraction, Phenyl-Toyopearl chromatography, and Toyopearl HW-65S gel filtration. The molecular weight of this enzyme was 300,000 by SDS-gradient-PAGE. The optimum temperature and pH were 37–45°C and 4.0–4.2. The enzyme was stable at below 45°C and at pH 3.5–5.2 for 30 min treatment. This enzyme synthesized dextran from maltooligosaccharides except for maltose, from which a little glucose and panose were produced. On the reaction with G4, the enzyme synthesized dextran and also maltose, panose, and a small amount of glucose as byproducts. Acetobacter dextran synthesized from G4 was compared with commercial Leuconostoc dextran by dextranase digestion, and it was suggested that these structures were different from each other.

Effect of sprouting on carbohydrate content of fluted pumpkin seed

The concentrations of individual sugars contained in both dormant and sprouted fluted pumpkin seed ( Telfairia occidentalis, Hook F.) were determined. Thin-layer chromatography (TLC) of extracts from fluted pumpkin seed showed marked reduction in the total carbohydrate concentration due to sprouting with corresponding increase in the total soluble sugar concentration. The carbohydrates of dormant fluted pumpkin seed consist mostly of sucrose and small amounts of glucose, fructose, galactose, raffinose and stachyose, while sprouted seed contained mostly glucose, fructose, maltose and a low concentration of sucrose and one unidentified sugar.

FRUCTANS ISOLATED FROM FLOWERS AND STEMS OF CHRYSANTHEMUM MORIFOLIUM

In order to more fully understand flower growth and development, we are interested in carbohydrate partitioning and metabolism in floricultural crops. In recent work with Chrysanthemum, we noted the occurrence of several early-eluting carbohydrate peaks (as detected by HPLC with a resin-based column in the calcium form). These peaks were present in flowers and stems, and in lesser amounts in leaves. Acid hydrolysis of the unknowns liberated large amounts of fructose and much smaller amounts of glucose, indicating that these peaks are fructans, or medium chain-length fructose polymers. Fructans represented 10% and 25% of the carbohydrate in a 12:5:3 methanol: chloroform: water extract of leaves and stems, respectively. Flower petals were extracted with 95%. ethanol, then with water. Fructans accounted for more than 40'% of the water soluble carbohydrate in flower bud tissue. It is likely that fructans serve as a major reserve carbohydrate in Chrysanthemum. Additional studies are underway to better characterize flower petal fructans, and to understand their role in flower development.

POLLINATION BIOLOGY OF PLATANTHERA STRICTA (ORCHIDACEAE) IN OLYMPIC NATIONAL PARK, WASHINGTON

Platanthera striata Lindley is entomophilous and can produce seed via facultative self‐pollination and intraracemic and interracemic pollination. Capsule production is pollinator‐limited and seed set may be pollen‐limited. In experimental plants capsules produced via self‐ and intraracemic pollination contained fewer seeds with normally developed embryos than did capsules produced via interracemic pollination. The inflorescence of Platanthera stricta is fragrant and is attractive to a wide array of anthophilous insects. It is pollinated by a diverse assemblage of short‐tongued insects. The primary pollinators are Eustroma fasciata B. and McD. (Lepidoptera: Geometridae), Bombus flavifrons Cresson and B. melanopygus Nylander (Hymenoptera: Apidae), an undescribed species of Greya (Lepidoptera: Prodixidae), and several species of Empis, Rhamphomyia, and Anthepiscopus longipalpis Melander (Diptera: Empididae). Small amounts of glucose are present on the raceme. The extrafloral glucose may retain small pollinators on the inflorescence until they locate the floral spur aperture.