Cellulase Enzyme Components

The hypothesis put forth concerning steric effects in acid hydrolysis would have as its corollary the proposal that the role of the Ci component in cellulase enzyme system complexes is to disrupt the engagement of the C6 oxygen in the bifurcated intramolecular hydrogen bond and thus permit rotation of the C6 group into positions more favorable to hydrolytic attack. 

Concerning the enzyme acted on the substrate, some researchers considered all three components of the cellulase enzyme system (endoglucanases, cellobiohydrolases, and cellobiase). Since the kinetic behavior of the three enzyme system are different and not fully understood, simplified models were also suggested by assuming the cellulase system can be represented quantitatively by a single enzyme. 

Capitalizing on this metabolic difference between higher forms of life and micro-organisms is the basis for this research approach to wood protection. Compounds are available which inhibit the cellulase enzyme systems however, their specificity has not been determined. Mandels and Reese (21,22) found that the extracts from the immature fruit of persimmon or the extract from leaves of bayberry were very effective inhibitors of the cellulase system. At concentration levels of. 00005 and. 00018%, respectively, these two extracts inhibited the cellulase enzymes isolated from Trichoderma viride. It is not known what the active component(s) are in these two extracts. 

Not all cellulase enzymes give identical results, even with similar fabrics in similar equipment. Cellulases derived from Trichoderma typically are the most aggressive in their action, whereas mono-component endo-glucanases often require the most mechanical action to achieve the desired effects. Slow deactivation of the cellulases during transport and storage can adversely affect the reproducibility of the resulting effects. If cotton is not washed carefully before bio-finishing,... 

By the mid-1990s, several new cellulase enzyme products had evolved for denim washing. Fower degrees of fabric strength loss were achieved with individual cellulase enzyme components, most prominently Trichoderma EG3 [16] and Humicola EGS [17]. Trichoderma cellulase used in combination with protease improved its performance to close to that of the Humicola cellulase [18]. 

The distribution of individual cellulase enzymes in two prominent crude cellulases, those produced by Trichoderma longibrachiatum Rut C30 and Humicola insolens DSM 1800, are listed in Table 6. Note that the component designations... 

It is often desirable to enhance or deplete the cellulase enzyme mixture of one or more individual cellulase components. This is done if one or two components are particularly desired, or if one or more are deleterious to the application. In the extreme, only a single cellulase component is produced. In one example of this, pure Trichoderma endoglucanase III is produced by extracting it with polyethylene glycol [16]. 

Viscosity loss (Figure 8) is brought about by enzymes, mainly cellulases, produced as organisms break down components such as cellulose ether thickeners. 

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