Kinetics cellulose hydrolysis

Stability and Performance of Bound En me. The stability of the IME was determined by two methods. One measurement of bound activity was obtained using traditional cellulose hydrolysis experiments (described below). In the other method, direct kinetic parameter measurements were obtained using a recirculating differential (RDR) reactor system following the method of Ford et al. (46). 

To illustrate the procedure for the development of kinetic models of the cellulose hydrolysis, let s examine the model proposed by Ryu et al. (1982). A kinetic model for the enzymatic hydrolysis of cellulose was derived based on the following assumptions ... 

Howell, J. A. and J. D. Stuck, "Kinetics of Solka Floe Cellulose Hydrolysis by Trichoderma viride Cellulase," Biotechnol. Bioeng. 17 (1975) 873-893. 

We have therefore studied the kinetics of cellulose hydrolysis and glucose decomposition under extremely dilute H2S04 (0.05-0.2 wt%, pH 1.5-2.2) and high-temperature (200-230°C) conditions. Our ultimate goal is to better understand the kinetics of dilute-acid hydrolysis of biomass and develop promising acid hydrolysis processes that can give both high... 

Torget, R. W., Kim, J. S., and Lee, Y. Y., Fundamental aspects of dilute acid hydro lysis/fractionation kinetics of hardwood carbohydrates. 1. Cellulose hydrolysis. Industrial Eng Chem Res 2000, 39 (8), 2817-2825. 

Keywords. Cellulases, Cellulose, Hydrolysis, Model Mechanism, Structure, Kinetics... 

Enzymatic action can be defined on three levels operational kinetics, molecular architecture, and chemical mechanism. Operational kinetic data have given indirect information about cellulolytic enzyme mode of action along with important information useful for modeling cellulose hydrolysis by specific cellulolytic enzyme systems. These data are based on measurement of initial rates of enzyme hydrolysis with respect to purified celluloses and their water soluble derivatives over a range of concentrations of both substrate and products. The resulting kinetic patterns facilitate definition of the enzyme s mode of action, kinetic equations, and concentration based binding constants. Since these enable the enzymes action to be defined with little direct knowledge of its mechanistic basis, the rate equations obtained are referred to as operational kinetics. The rate patterns have enabled mechanisms to be inferred, and these have often coincided with more direct observations of the enzyme s action on a molecular level [2-4]. 

Because free cellulose chain ends are so difficult to quantify, other measurable cellulose characteristics have been shown to be factors correlating to hydrolysis susceptibihty and rate [15,18]. These factors affect how well the cellulose-binding domain, CBD, adheres to the cellulose and how well the catalytic domain acts on the cellulose. Because of what can and cannot be measured easily, models of enzymatic cellulose hydrolysis combine adsorption behavior with kinetic action. 

Data and kinetic models of dilute acid pretreatment ate vital to provide a foundation for undostanding hemicellulose hydrolysis and the cause of enhanced performance by flow system systems. Initial hemicellulose hydrolysis models were adapted from Saeman s first-order homogeneous kinetic model of cellulose hydrolysis in a dilute acid batch system (30) and later modified to include two different fractions of hemicellulose, one of which is more easily... 

The kinetics of alkaline hydrolysis of a series of eleven vinylsulphone reactive dyes fixed on cellulose have been investigated at 50 °C and pH 11. Bimodal hydrolytic behaviour was observed under these conditions, the reaction rates being rapid at first but becoming slower as the concentration of fixed dye remaining gradually decreased. These results were attributed to differences in the degree of accessibility of the sites of reaction of the dyes within the fibre structure [87]. 

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