EFFECT OF ADSORPTION OF ENDOGLUCANASE ON THE DEGRADATION OF MICROCRYSTALLINE CELLULOSE

The influence of adsorption of endoglucanases on enzymatic hydrolysis of microcrystalline cellulose was investigated. All the data of adsorption on microcrystalline cellulose were found to obey the Langmuir adsorption isotherm. The values of adsorption affinity for endoglucanases increased in regular sequence of EG IV<EG III<EG I<EG II. It was found that the mechanisms of enzymatic hydrolysis of a crystalline and an amorphous cellulose are different. The hydrolysis of amorphous cellulose with endoglucanase depends on its activity. But the hydrolysis of microcrystalline cellulose with endoglucanase is directly correlated with its adsorption affinity. The major factor related to cellulases that control the difference in the reactivity of the crystalline and amorphous cellulose appears to be the adsorption affinity of endoglucanase on cellulose. From the results of hydrolysis with endoglucanases (EG I, II, III, and IV) in combination with cellobiohydrolase (CBH II), the reducing sugar produced during degradation is increased when the enzyme system contains endoglucanase with high affinity to cellulose.