Glucose kinetic investigation

Enzyme containing Nation membranes prepared according to the proposed protocol have shown high specific activity and stability of immobilized glucose oxidase. As expected, the simplicity of preparation provided high reproducibility. When the same casting solution is used, the maximum deviation in membrane activity is <2%. This, however, is also the precision limit for kinetic investigations. 

Morrison, J. F. and Ebner, K. E, 1971B. Studies on galactosyltransferase. Kinetic investigations with glucose as the galactosyl group acceptor. J. Biol. Chem. 246, 3985-3991. 

In principle, several routes exist for enzymatic isomaltose synthesis. With respect to cost-effectiveness it is obvious that one should use substrates like sucrose or starch that can be exploited by dextransucrase (EC 2.4.1.5) or glucoamylase (EC 3.2.1.3), respectively. However, in both cases, isomaltose represents a side product which is released only in small proportions next to dextran or glucose as main products. Realization of higher yields requires extensive time and effort with respect to engineering of reaction and catalyst design. Based on kinetic investigations dextransucrase has been chosen for the production of isomaltose with sucrose as the substrate, and glucose as an acceptor (see Sect. 2.1). 

This mechanism implies that a portion of the charred residue from the pyrolysis of cellulose could be derived from the secondary reactions involved in the decomposition of levoglucosan. In the production of levulinic acid, about 25 % of the initial D-glucose residues is converted into the humin that separates as an insoluble, charred residue. This humin could be formed from 5-(hydroxymethyl)-2-furaldehyde, which is readily polymerized and decomposed on heating under acid conditions. The kinetic investigations indicate that the humin could also be formed from the reaction of 5-(hydroxy-methyl)-2-furaldehyde with one of its precursors. ... 

The results of the kinetic investigations proved that glucose oxidation mechanism is the same as established for other substances oxidized in the presence of this catalytic system. The kinetic equation of gluconic acid formation rate appears as follows ... 

SECM has been employed to detect the catalytic activity of a variety of immobilized enzymes or enzyme labels including glucose oxidase [27, 58,122-124], urease [44, 125], nitrate reductase [126], diaphorase [72,127,128], horse radish peroxidase [129], NADH-cytochrome C reductase [28], and alkaline phosphatase [54]. When the enzyme kinetics are too slow for feedback measurements, genera tion/collection mode can be used. In this section, we discuss kinetic investigations and analytical appKcations, but leave patterning of activity to Sect. 3.3.4.4 on microfabrication. 

In 1994, Laketic et al. investigated for the first time the hydrolysis of sucrose over dealuminated-Y-zeolites with different Si/Al ratio (27, 55, 110). The best activity was observed with the highest dealuminated zeolite (Si/Al = 110, rate constant = 1.28 L moE min at 30°C [32]). As expected, the reaction obeys first order kinetics. Up to 90% conversion was obtained after 9 h of reaction at 70°C. Interestingly, little side-products were formed as the selectivity in glucose was higher than 90%. 

The Mn(II)-catalysed oxidation of glucose by peroxodisulfate ions occurs via a radical-chain mechanism.26 Kinetics of oxidation of thiodiglycollic acid by (trans-cyclohexane-l,2-diaminc-/V, N, N, /V -tetraacetatolmanganateilJI) have been investigated.27 Oxidations of ketoses and aldoses by manganese(IV) in sulfuric acid media have a first-order dependence on sugar and fractional-order dependence on oxidant.28 A mechanism has been proposed for the oxidation of L-malic acid by Mn(III) pyrophosphate in aqueous acid, involving complex formation and radicals.29... 

The present study investigated the inhibition of Saccharomyces cerevisiae by the liquid hydrolysate and the kinetics of enzymatic hydrolysis of the solid components produced by the pretreatment of aspen wood and corn stover by liquid hot water and hot carbonic acid. Inhibition of yeast was determined by measuring the rate of glucose consumption by yeast growing in hydrolysates produced at various reaction severities. The enzymatic hydrolysis rates of pretreated solids was determined by measuring rates of sugar accumulation of enzyme-digested pretreated solids. 

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