Cellulose enzymic hydrolysis

General protease, a-amylase, and exoglucanase activities were estimated using hide powder-, amylose-, and celliilose-azure substrates, respectively, as described earlier (49). Here, standard curves were developed for the hydrolysis of each azure-linked substrate by standard enzymes of known activity. By this method, one cellulose-azure hydrolysis unit corresponds to one filter paper unit, one unit of hide powder-azure activity corresponds to the hydrolysis of 1.0 nmole of iV-benzoyl-L-tyrosine ethyl ester (BTEE) per min, and one amylose-azure unit of activity corresponds to the hydrolysis of 1.0 nmole of maltose from starch per 30 min. 

Perlin, A. S., Advances in Enzymic Hydrolysis of Celluloses and Related... 

Cowling, E. B. In "Enzymic Hydrolysis of Cellulose and Related Mate-... 

Properties of the Substrate HEC in Relation with its Enzymic Hydrolysis. HEC is the reaction product of cellulose with ethylene oxide and has the special property that its hydroxyethyl groups can react again with ethylene oxide to form oligomeric side chains. 

Paper Separations. The separation of the inorganic components from the remainder of the paper by differential centrifugation of a suspension of the paper dispersed in a fluid before X-ray examination may also be useful. Insoluble components could be obtained directly, while soluble components would have to be extracted and isolated by evaporation. However, this dispersion process would probably lead to a modification of the components or their structures. The same is true for the possible removal of the cellulose by hydrolysis in the presence of commercially available enzymes. 

Coughlan MP. Enzymic hydrolysis of cellulose An overview. Bioresour Technol 1992 39 107-115. 

The >3(1 — 4) linkage is particularly stable with respect to hydrolysis. Cellulose cannot be digested by mammals, but some insects (notably termites and wood-eating cockroaches), protozoans and fungi possess celluloses, enzymes that can hydrolyze the /3(1—>4) linkages. Ruminants, such as sheep and cattle, can digest cellulose because of the protozoans that live symbiotically in their digestive system. 

Enzymatic Hydrolysis. Saccharification of wood polysaccharides to sugars can be accomplished by enzymatic techniques instead of acid hydrolysis. The U.S. Army Natick Laboratories developed a method for conversion of cellulose to glucose with a cellulose enzyme from an active strain of the fungus Trichoderma viride. However, extensive pretreatment of wood is necessary before sufficient enzymatic hydrolysis will take place. 

It should be possible to improve the efficiency of the cellulose enzyme complex for hydrolyzing cellulose to glucose. The enzyme complex apparently contains decrystallizing and hydrolysis enzymes that work together to convert cellulose to glucose. Isolation of the specific enzymes and genetic engineering could provide a more efficient complex. 

Balousek PJ, McDonough TJ, McKelvey RD, Johnson DC (1981) The effects of ozone upon a lignin model containing the /1-aryl ether linkage Sven Papperstidn 84 R49-R54 Bes RS, Gas G, Molimer J, Vidal P, Mathieu J, Mora JC (1989) Enhancement of poplar cellulose susceptibility to cellulase enzyme hydrolysis by ozonation Ozone Sci Eng 11 217-226... 

Mandels, M., Reese, E. T. in Advances in Enzymic Hydrolysis of Cellulose... 

There have been numerous studies exploring the concept of membrane reactors. Many of them, however, are related to biotechnological applications where enzymes are used as catalysts in such reactions as saccharification of celluloses and hydrolysis of proteins at relatively low temperatures. Some applications such as production of monoclonal antibodies in a hollow fiber membrane bioreactor have just begun to be commercialized. 

Derivation Hydrolysis of cornstarch with acids or enzymes, hydrolysis of cellulosic wastes. 

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]. 

Cellulose is a heterogeneous substrate that makes modeling cellulolytic enzyme hydrolysis difficult. Cellulose is composed of chains of glucose connected by P 1-4 glycosidic bonds. One chain end is termed the reducing end because the hemiacetal is able to open to expose the reducing aldehyde. The other chain end is called the non-reducing end because the 1 carbon in the hemiacetal is involv-... 

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