[Saccharification of corn stover by immobilized Trichoderma reesei cells]

The mycelia of Trichoderma reesei Rut C30 were adsorbed and immobilized within the porous polyurethane supporter. It was found that the synthesis of cellulase by the immobilized cells and the enzymatic hydrolysis of corn stover were able to be carried out in a nitrogen source-limiting medium. Under repeated batch processes with 60 g/L corn stover pretreated by 2% NaOH at 85 degrees C, the average cellulase activity (FPA) was 0.70 IU/ml, the concentration and yield of the reducing sugar were 26.41 g/L and 89.11% respectively after shaking culture at 150 r/min, 30 degrees C, pH 4.8 for 108 h. Total of 12 repeated batches were performed in 54 days. The immobilized cells kept the weight around 10 g/L. The fed-batch process was also studied with the same immobilized cells. Total of 120 g/L corn stover was added in different feeding manners. The reducing sugar of 52.8 g/L was produced after 7 days and the saccharification efficiency (89.2%) was almost the same as the batch process. The results indicated that the cellulase production and cellulosic material saccharification in situs by the immobilized Trichoderma reesei cells is an convenient and effective process for conversion and utilization of renewable biomass.