초록
Wheat straw was ground and pretreated with a thermomechanical process before exposure to a mixture of cellulases (Celluclast). The thermomechanical process known as DIC (Detente Instantanee Controlee), which is similar to the steam explosion process, was used to pretreat the lignocellulosic biomass through a flash expansion. The results demonstrate that crushing the wheat straw increased the hydrolysis yields. The initial hydrolysis rates and the final yields of hydrolysis increased relative to those of the untreated straw as a result of the DIC pretreatment. After optimization, the hydrolysis process resulted in a glucose yield of 31g/100g of straw, which corresponds to approximately 90% of the theoretical cellulose value. A fermentation procedure was performed using the microorganism Saccharomyces cerevisiae, and the results confirmed the production of bioethanol (11.5g/100g of pretreated straw). The adsorption isotherms of cellulases on wheat straw and the enzyme kinetics of hydrolysis of the wheat straw were also studied using different concentrations of Celluclast. The kinetic parameters (maximal velocity, V<SUB>emax</SUB>, and half-saturation constant, K<SUB>e</SUB>) were determined from the initial velocities. K<SUB>ad</SUB> (adsorption coefficient) results show that the DIC pretreatment of the straw decreased K<SUB>ad</SUB> six-fold compared to that of the untreated straw (15.54 vs 2.52g of enzymes/g of biomass, respectively), confirming that the DIC pretreatment produced a substrate that is more accessible to cellulases.