(481c) Measurement of Endo and Exo-Glucanase Activities in Cellulase Using Non-Crystalline Cellulose

Non-Crystalline Cellulose ( NCC) is a product of our laboratory. X-ray crystallography has confirmed that NCC has highly amorphous character with less than 10% crystallinity. NCC can be prepared into materials with varying properties having different DP & Crystallinity. Because of the amorphous nature and open structure of NCC, large amount of soluble cello-oligosaccharides (COS) are formed along with cellobiose(G2) and glucose(G1) as hydrolysis products. Large numbers of reaction observables coming from variety of NCC substrates provide valuable information pertaining to the Celluase reaction that is not available from crystalline cellulose. These data were analyzed to understand the intrinsic reaction mechanism and physical factors affecting the reaction. Consequently, a procedure has been developed for measurement of the activities of cellulase components, i.e. Exo-glucanase(Exo-G) and Endo-glucanase(Endo-G) simultaneously in a single experiment using NCC as the sole substrate. When NCC is incubated with very low enzyme loading, initial release of G1+G2 indicates Exo-G activity whereas the change in number of reducing ends indicates the Endo-G activity. The results were compared with the conventional method of measuring Exo-G and Endo-G activities which rely on Avicel and CMC, in which a good agreement was found. Use of NCC as a standard substrate can therefore simplify the method of measuring the cellulase activities without affecting the accuracy.