Enzyme, cellulolytic

These data amply confirm the original contention concerning the feasability of using cellulolytic enzyme systems for the isolation of additional amount of native lignin from various woody tissues. Moreover, this method can be applied not only to perennial plants, but also to annual plants. 

Cellulase is not produced in the human digestive system. Cellulolytic enzyme preparations obtained from A. niger or other fungal sources are available, and it is thought that their ingestion may improve overall digestion, particularly in relation to high-fibre diets. 

Teeri, T. The cellulolytic enzyme system of Trichoderma reesei Doctoral Thesis VTT Publications 38 Technical Research Center, Espoo, FL, 1987... 

Further progress can be expected in the area of selective inhibition and inactivat-iem of cellulases undesirable in xylanase preparations. There is a possibility of finding natural selective cellulase inhibitors or developing highly reactive derivatives of cello-biose and cellodextrins that inactivate cellulolytic enzymes. 

An Affinity Chromatographic Method for the Purification of Some Cellulolytic Enzymes... 

Thus a biospecific adsorbant was obtained selective desorption should therefore permit successive elution of cellulolytic enzymes. It was thus found that the method was very useful in the purification of the cellobio-hydrolases from Tr. r., starting from very crude culture filtrates. Addition of glucose (0.1M) or gluconolactone suppressed the action of glucosidases present, preventing deterioration of the columns. The capacities exceeded 10 mg CBH I per ml gel (prepared with CNBr activated Sepharose). 

The xylanolytic enzyme system of Trichoderma reesei, a well-known producer of cellulolytic enzymes, is versatile and well suited for the total hydrolysis of different xylans. It consists of two major, specific and several non-specific xylanases, at least one / -xylosidase, a-arabinosidase and a-glucuronidase and at least two acetyl esterases. The hydrolysis of polymeric xylans starts by the action of endoxylanases. The side-groupcleaving enzymes have their highest activities towards soluble, short xylo-oligosaccharides, and make the substituted oligosaccharides again accessible for xylanases and / -xylosidase. 

While Trichoderma reesei is best known as an efficient producer of cellulolytic enzymes, it has also been reported to produce xylanase and / -xylosidase (18-20). Two xylanases and a / -xylosidase have been purified from T. reesei (10), and two xylanases (21,22) and a / -xylosidase (5) from T. viride. We have previously shown that T. reesei produces all the enzymes needed for complete hydrolysis of native substituted xylans (23). One xylanase (24), a / -xylosidase (25), an a-arabinosidase (26), and an acetyl esterase (27) of T. reesei have so far been purified. In this chapter, the mode of action of these enzymes in the hydrolysis of different xylans is discussed. 

The culture filtrates of T. reesei contained a large number of both cellulolytic and hemicellulolytic enzymes, which could be partially separated by chromatofocussing (Fig. 1). Of the cellulolytic enzymes, several endoglu-canases and two cellobiohydrolases have already been isolated and characterized (30). Some of the endoglucanases isolated are nonspecific and have xylanase activity (31). The two major xylanase (Xyl) peaks in Figure 1 corresponded to pi-values of above 7.5 and 5.5. When the former enzyme was further purified (24), its isoelectric point was found to be about pi 9 (Table I). Previously, the presence of at least three electrophoretically different xylanases in T. reesei culture filtrates was reported, with the most acidic one shown to have broad substrate specificity (10). This is in agreement with the reported occurrence of three xylanases (pi > 7, pi 5.1, pi... 

Sherwood, R.T. and Kelman, A. 1964. Measurement of pectinolytic and cellulolytic enzyme activity by rotating spindle viscometry. Phytopathology 54 110-112. 

There are many sources of cellulolytic enzymes however, the fungus Trichoderma viride has proved to be the most effective source to date. The microbiology (25,32) and enzyme kinetics (24,30) studies on this organism have been pioneered by workers such as Reese and Mandels at... 

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