Effects of surfactants on enzymatic saccharification of cellulose have been studied. Nonionic, amphoteric, and cationic surfactants enhanced the saccharification, while anionic surfactant did not. Cationic and anionic surfactants denatured cellulase in their relatively low concentrations, namely, more than 0.008 and 0.001%, respectively. Using nonionic surfactant Tween 20, which is most effective to the enhancement (e.g., the fractional conversion attained by 72 h saccharification of 5 wt % Avicel in the presence of 0.05 wt % Tween 20 is increased by 35%), actions of surfactant have been examined. As the results, it was suggested that Tween 20 plays an important role in the hydrolysis of crystalline cellulose and that Tween 20 disturbs the adsorption of endoglucanase on cellulose, i.e., varies the adsorption balance of endo- and exoglucanase, resulting in enhancing the reaction. The influence of Tween 20 to the saccharification was found to remain in simultaneous saccharification and fermentation of Avicel.

The adsorption of cellulase from Trichoderma viride (Meicelase CEP) on the surface of pure cellulose was studied. The adsorption was found to obey apparently the Langmuir isotherm. From the data concering the effects of temperature and the crystallinity of cellulose on the Langmuir adsorption parameters, the characteristics of the adsorption of the individual cellulase components, namely CMCase (endoglucanase) and Avicelase (exoglucanase), were discussed. While beta-glucosidase also adsorbed on the surface of cellulose at 5 degrees C, it did not at 50 degrees C.

Rice straw and bagasse with water content 84 or 94% were irradiated with microwave (245OMHz) in sealed glass vessels. This treatment enhanced markedly the accessibility of the cellulosic materials for the enzymatic hydrolysis: for example, 1.6 times in the rice straw by the microwave treatment at 170°C for 5 min and 3.2 times in the bagasse by the treatment at 200°C for 5 min, compared with the untreated.

Pure cellulose (Avicel) was hydrolyzed batchwise at 50 degrees C and pH 4.8 by cellulase from Trichoderma viride (Meicelase CEP). Then the effects of the crystallinity of cellulose as well as the thermal deactivation and product (cellubiose and glucose) inhibition to cellulose on the hydrolysis rate were quantitatively investigated. While these factor had evidently retarded the enzymatic hydrolysis of cellulose to a significant extent, the hydrolysis rates observed could not be explained. For practical purposes, an empirical, simple rate expression was developed which included only one parameter: a overall rate retardation constant. This empirical rate expression held for the hydrolysis of at least two kind of cellulosic materials: Avicel and tissue paper.

Hydrolysis of pure cellulose Avicel has been carried out, using Meicelase from Trichoderma viride, where the enzymatic activity of cellulase adsorbed on cellulose and its changes during the hydrolysis were investigated. A rapid drop of the hydrolysis rate during the reaction, that is always observed in enzymatic hydrolysis of cellulose, could be explained by a decline of specific activity of adsorbed enzyme, and it was implied that the decline results from a loss of synergistic action between endoglucanase and exoglucanase. An empirical equation expresses the change of hydrolysis rate during the reaction and also shows that the change of the hydrolysis rate is caused by the decline of the specific enzymatic activity of adsorbed enzyme.