Maltose Solutions Research Articles

Nutrition and chemotaxis in the myxomycete Physarum polycephalum: the effect of carbohydrates on the plasmodium.

SUMMARY: The ability of a range of carbohydrates to support the growth of plasmodia of the myxomycete Physarum polycephalum was investigated and a method for the objective study of the chemotaxis of plasmodia was developed. Plasmodia showed positive chemotaxis to solutions of glucose, maltose, mannose and peptone, and to galactose after a delay. They did not respond to sucrose, fructose or ribose. The chemotactic effectiveness of sugars paralleled their ability to support growth.

Activity Coefficients of Aqueous Xylose and Maltose Solutions

Abstract Osmotic and activity coefficients of aqueous xylose and maltose solutions at 25°C are measured by the isopiestic vapor pressure method. Densities of these solutions are also determined at 25°C. The activity coefficients of water in these solutions show that both xylose and maltose solutions do not behave as regular solutions. Second virial coefficients for xylose and maltose are calculated from partial molar volumes of the solute and the solvent at infinite dilution and empirical equations of water activity coefficient. The coefficients calculated for xylose and maltose are 111 and 248 cc/mol, respectively. Second virial coefficients for these sugars and a few other sugars are approximately proportional to the molecular weight. This relation is explained by the van der Waals model.

Diffusion Coefficients of Xylose and Maltose in Aqueous Solution

Abstract Diffusion coefficients for the systems aqueous xylose solution and aqueous malotse solution at 25°C were measured by the Rayleigh interference method. Viscosities of these systems were also determined. The concentration dependence of diffusion coefficient for maltose solution is well described by the Gordon relation. For xylose solution, however, a small deviation from this relation is observed. The translational frictional coefficient of maltose was calculated by the shell model of Bloomfield et al. If the effect of the local viscosity around a molecule of the solute is corrected, the agreement between the calculated and the observed values is satifsactory.

The utilization of trehalose during flight by the housefly, Musca domestica

The male housefly, Musca domestica, utilizes trehalose during flight. However, the rate of utilization of treahlose is most rapid during the first few minutes of continuous flight (i.e. during the first 5 min of flight, the rate of utilization of trehalose is 187 μg/thorax per hr; this results in a thoracic trehalose level of one-third of that of the unflown fly, after 5 min of flight). However, as the period of flight is extended, the apparent rate decreases very rapidly, so that the thoracic trehalose level actually continues to rise with increasing duration of flight period. It is concluded that, following initial rapid utilization of trehalose, a secondary metabolic pool becomes implicated, so as to restore (and maintain) the thoracic trehalose levels at as high as 50 per cent of that of unflown flies, for thoraces of flies which have been permitted to fly for as long as 4·5 hr. Flight-exhausted flies, when fed on a solution of glucose, fructose, maltose, sucrose, and trehalose, resumed flight, without external stimulation, but feeding galactose, mannose, and cellobiose failed to do so. However, injection of solutions of glucose, fructose, sucrose, and trehalose did not initiate flight in such flight-exhausted flies. These data indicate that a complex, metabolic route is normally involved in the energizing of flight.

Preparation and use of insolubilized amyloglucosidase for the production of sweet glucose liquors

AbstractAmyloglucosidase (EC. 3.2.1.3), partially purified from an Aspergillus species, was chemically attached to DEAE cellulose using the bifunctional reagent 2‐amino‐4,6‐dichloro‐s‐triazine. The action of the insolubilized enzyme derivative on dilute maltose and dextrin solutions was studied in a packed bed. A second and deeper bed was used to demonstrate the possibility of a continuous process for raising the dextrose; equivalents of “glucose” liquors of high concentration formed by acid hydrolysis of maize starch.

A continuous fermentation technique for studying the kinetics of sugar uptake by baker's yeast.

1. Solutions of glucose, maltose or other sugars were pumped at controlled rates into a yeast suspension and the extracellular sugar concentration was determined. The technique was especially suitable for studying the kinetics of fermentation at low rates of sugar utilization. At high rates the fermentation system was unstable. 2. Glucose fermentation was fitted by a model in which a diffusion barrier with first-order kinetics is interposed between the environment and the site of hexokinase. 3. Aerobic conditions affected the fermentation enzyme system but not the diffusion mechanism. 4. The kinetics of maltose fermentation at low rates approximated to those of the hydrolysis of maltose by the enzyme maltase, as studied in suspensions of broken cells.

The optical properties of solid carbohydrates irradiated with ? radiation

The ultraviolet absorption spectra, the optical activity and the reference index of solutions of glucose, sucrose, and maltose prepared from irradiated powders were investigated.

Effects of variable effort expenditure on subsequent preference for the reinforcer

Four groups of male albino rats received the same number of reinforcements of 0.1 cc maltose solution in a Skinner box. Three of these groups received their reinforcement contingent upon pressing a bar weighted at 20 gm, 50 gm, and 80 gm respectively. The fourth group received reinforcements noncontingent upon the bar press. A control group received noncontingent reinforcements of 0.1 cc distilled water. Following training, all five groups were given a cafeteria-style preference test in which the same maltose solution, used as a reinforcer, was available along with an alternative solution of sucrose. The consumption measures indicated a linear decline in Ss’ preference for the reinforcer, as a function of increased effort expenditure.

Effects of fixed ratio training on subsequent preference for the reinforcer

Four groups of albino rats received the same number of 0.1 cc maltose-solution reinforcements in a Skinner box, either on FR 10, FR 5, Crf, or noncontingent upon the bar press. In addition, a water-reinforced control group received the same number of 0.1 cc noncontingent distilled water reinforcements. Subsequently, all Ss were given a cafeteria-style preference test with the same maltose solution used during training and an unfamiliar sucrose solution as alternatives. All measures revealed a decline on the part of the fixed ratio groups in preference for the solution used as a reinforcer during training. This contrasts with a previous report that the effect of high effort training on reinforcement value is incremental.

34. Radiation chemistry of carbohydrates. Part XIII. Action of γ-radiation on oxygenated solutions of maltose

When maltose is irradiated with Co/sup 60/ gamma radiation in oxygenated solution, the predominating initial process is a hydrolytic type of scission to glucose. There is accompanying oxidative scission, to yield gluconic acid. Maltobionic acid and an additional disaccharide acid, probably formed by oxidation of a 6-CH/sub 2/. OH group, are also initial products. Radioactive- tracer and paper-chromatographic methods were used to obtain yield-dose curves for the products and to measure the rate of degradation of maltose (initial -G 4.0), which is of the first order in maltose. Secondary degradative processes lead to additional products at doses higher than 2 x 10/sup 20/ ev ml/sup -1/. The effect of maltose concentration on the radiative decomposition was examined, and possible mechanisms are discussed. A post-irradiation process leads to the formation of acid, reduction in hydrogen peroxide, and decrease in intensity of the ultraviolet absorption at 267 m mu . The after-effect is shown to be a thermal reaction due to hydrogen peroxide. (auth)

Longevity of conidia of Botrytis fabae sardiña

The numbers of conidia produced by Botrytis fabae on agar media increased up to the tenth day after inoculation, when the average age of conidia was 3 days. Germination in water of conidia from cultures differing in age between 10 and 40 days was equally high but those from cultures 25 and 35 days old were only 1/10 and 1/100 as infective as conidia from 10-day-old cultures. Suspending conidia from cultures up to 40 days old in a solution (0·2% or higher concn.) of either yeast extract or orange juice partially restored in-fectivity, as did solutions of sucrose, glucose, mannose and maltose, but fructose and galactose were less effective. Arabinose, xylose, casein hydrolysate, peptone and nucleic acid did not increase infectivity. Abrading leaves with ‘Celite’ before inoculation increased the numbers of infections produced by spores suspended in water; the increase, as with adding sugars, was greater with old than with young conidia.

STUDIES ON CARBOHYDRATE-METABOLIZING ENZYMES. V. SYNTHESIS OF OLIGOSACCHARIDES FROM MALTOSE AND GLUCOSE BY YEAST ENZYMES*

Incubation of a 15% solution of maltose with a brewer's yeast maltase preparation resulted in the formation of small amounts of oligosaccharides. These have been separated by charcoal-Cefite chromatography, and characterized by chemical and enzymic methods as isomaltose, panose and maltotriose. The same enzyme preparation also catalysed limited oligosaccharide synthesis from glucose. Possible mechanisms of saccharide synthesis are discussed and the properties of yeast maltase and of other maltases are compared.

575. Effects of γ-radiation. Part IV. The degradation ofD-glucose in aqueous solution by γ-irradiation in vacuo

The effect of Co/sup 60/ gamma -radiation on aqueous solutions of glucose and maltose in vacuo was studied. Gluconic acid and 2-oxo-D-arabino- aldohexose were isolated as products. The latter was determined by a method utilizing its ready reaction with o-phenylenediamine. Evidence for other products is presented and a degradation mechanism discussed. (auth)

ENZYME PRODUCTION BY YEASTS

The glucose-fermenting and maltose-fermenting activities (and in some cases the invertase activities) of yeasts grown in substrates containing various sugars (sucrose, d-glucose, invert sugar, beet molasses and maltose) have been estimated at various times throughout the fermentation between the time of initial addition of seed yeast to the medium and the time when all the sugar therein has been used. Certain enzyme adaptations have been found to take place which could have been anticipated; thus, a very high maltose-fermenting activity was developed in the yeast by growth and fermentation in a maltose solution—indeed, yeasts have been produced giving a greater gas production in maltose than in glucose solutions, supporting the theory that maltose may be fermented directly rather than after a preliminary hydrolysis to glucose. However, in many cases enzyme production has followed a surprising pattern; thus, the degree of ability to ferment maltose and glucose, and also the invertase content of the yeast, often proves to be a function of the stage of harvesting of the yeast crop as well as being influenced by the composition of the substrate.

Some factors affecting the formation of iodophilic polysaccharide in group D streptococci from the rumen.

SUMMARY: Of 25 isolates of α-haemolytic group D streptococci from the rumens of calves (Mann & Oxford, 1955), 7 produced intracellular iodophilic polysaccharide when grown aerobically or anaerobically in agar media containing starches of various origins, amylopectin, maltose, maltotriose, glycogen, amylose and amylopectin dextrins, or amylose glycollate. The iodophilic polysaccharide was not produced from glucose, sucrose, trehalose, glucose-1-phosphate, glucose-6-phosphate, cellobiose or amylose. These results are discussed in the light of the amylolytic action of the bacteria and known enzymic mechanisms of starch-type polysaccharide formation. In liquid media the polysaccharide was only produced from maltose when the cells were held at a pH value between 5 and 6, either by adjusting the reaction of the medium after the initial growth period, or by transferring the cells to a maltose solution buffered at the correct pH value and incubating further. Under the correct conditions polysaccharide formation was rapid. The polysaccharide was obtained in a partially purified form from the cells and appears to be unlike most ‘starches’ from bacteria so far reported. A possible explanation of the mode of development of an iodophilic reaction in streptococci in the rumen is given.

Fermentability of maltose

Pure maltose is fermented incompletely, but maltose with at least 1% d-glucose initially present can be fermented to the same extent as d-glucose. The still residues from incompletely fermented maltose solutions can be further fermented to produce the expected quantity of alcohol, but their reducing power is lower than that calculated for the unfermented maltose. The results obtained are consistent with the occurrence of a polymerization reaction as one of a series of competing reactions involved in the fermentation of maltose.

Transglycosidase activity of amylase preparations

A unit of transglycosidase has been defined tentatively as the amount of enzyme which will synthesize 1 mg. of oligosaccharides per hour at pH 4.4 and 30 °C. from a 1 30 M maltose solution. A method for determining the transglycosidase activity has been developed and described. Amylase preparations derived from fungal cultures, prepared either in the laboratory or obtained from commercial sources, all showed high transglycosidase activities; pancreatic preparations exhibited less yet appreciable transglycosidase activity. Transglycosidase has also been found to be present in barley malt and Bacillus subtilis preparations. Commercial amylase preparations derived from barley malt, however, showed no transglycosidase activity; the small amount of enzyme present in the original malt apparently was removed during purification. Transglycosidase of mold is essentially intracellular but is readily released into solution on standing.

Refractive indices of maltose solutions

The refractive indices of maltose hydrate solutions have been determined at 20° and at 25° C. Equations relating the refractive index to the percentage concentration of sugar have been p l'epal'ed from the observed data by the method of averages. A table, giving the refractive indices of mal tose solutions at I-percent intervals over a range of 1 to 65 percent of maltose hydrate at both 20° and 25° C, is included.

Refractive Indices of Maltose Solutions

Refractive Indices of Maltose Solutions

Refractive Indices of Maltose Solutions

The refractive indices of maltose hydrate solutions have been determined at 20° and at 25° C. Equations relating the refractive index to the percentage concentration of sugar have been p l'epal'ed from the observed data by the method of averages. A table, giving the refractive indices of mal tose solutions at I-percent intervals over a range of 1 to 65 percent of maltose hydrate at both 20° and 25° C, is included.