Enzymes cellulose decomposition

Figure 6. Both hydrolytic and oxidative enzymes participate in cellulose decomposition by the white-rot fungus Phanerochaete chrysosporium Burds. Hydrolytic enzymes i, endo-1 - - I ucanases 2, exo-1,4- -glucanase and 3, -glucosidase. Oxidative enzymes 4, glucose oxidase, 5, cMlobiose oxidise and 6, cellobiose quinone oxidoreductase. Adapted from Reference 23,...

No attempt was made at this symposium to include all aspects of cellulose decomposition. Surveys of active organisms and interrelationships of organisms growing on complex substrates are certainly important problems. So are the properties of enzymes and the means of enhancing and preventing their action. All impinge on the aim of this symposium which is to stress the practical application of cellulolytic systems to worldwide problems. 

Similarly, evidence directly points to inhibiting or altering the activity of other enzymes such as cellulose (tannins slow the decomposition of hemicellulose), catalase and peroxidase (phytotoxins affect the horseradish peroxidase breakdown of IAA), phosphorylase (polyphenols inhibit it in potatoes), and a host... 

Enzymes, immobiiized, are attached to a solid support by adsorption or chemical binding or mechanical entrapment in the pores of a gel structure, yet retain most of their catalytic powers -ase is a suffix identifying that the substance is an enzyme. The main part of the name describes the nature of the chemical reaction that can be catalyzed, as in cellulase, an enzyme that catalyzes the decomposition of cellulose... 

In the following discussion, we have assumed that wood decay is due to the concerted action of the individual enzyme systems responsible for cellulose, hemicellulose, and lignin decomposition. 

Ruminant nutritionists are primarily concerned with the microbial degradation and utilization of cellulose and other carbohydrates and the factors which will stimulate the same. This is in contrast to the interests of research workers in textile and wood industries whose main object is to prevent the decomposition of valuable products by cellulolytic microorganisms. Since a proper understanding of the mechanisms of breakdown of cellulose is essential to develop methods to prevent or stimulate the same, there is a convergence of interests at the enzymic level. 

The modification of cellulose with alkaline carbon disulfide to introduce xanthate groups has been extensively exploited in the industrial production of viscose. Early work on the preparation and properties of starch xanthate has been discussed. Xanthate derivatives of cellulose and starch have been discussed with respect to general xanthate chemistry, and the xanthation of cellulose in homogeneous medium is known to be a second-order reaction. Cellulose xanthate shows some potential as a matrix for enzyme insolubilization, " and stable derivatives of this xanthate may be prepared by transesterification. Thermal decomposition of cellulose allyl- and benzyl-xanthates gives 5,6-cellulosene. Some thiocarbonyl derivatives of polysaccharides have been prepared. "... 

Concentration of accumulated glucose, gm-mole/1 Initial concentration of cellulose, gm-mole/1 Cone, of glucose decomposition products, gm-mole/1 Enzyme concentration, mg ml" ... 

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