From the viewpoint of the conversion process, the most important factors to be taken into account for hydrolysis of cellulose contained in lignocellulosic materi­als are the reaction time, temperature, pH, enzyme dosage, and substrate load (Sanchez and Cardona, 2008). By testing lignocellulosic material from sugarcane leaves, Hari Krishna et al. (1998) have found the best values of all these param­eters varying in each experimental series the value of one of the factors while fix­ing the other ones. Sixty-five to seventy percent cellulose conversion was achieved at 50°C and pH of 4.5. Although enzyme doses of 100 FPU[1]/g cellulose caused almost a 100% hydrolysis, this amount is not economically justifiable. Hence, a 40 FPU/g cellulose dosage was proposed for which a 13% reduction in conversion was observed. Regarding the substrate concentration, solids loads of 10% were defined as the most adequate considering rising mixing difficulties and accumu­lation of inhibitors in the reaction medium. Though these conditions were deter­mined for a specific material pretreated by overliming and extrapolations to other lignocellulosic feedstocks are risky, found values are within the reported ones in the literature for a wide range of materials. Hydrolysis tests for steam-pretreated spruce also indicate the need of high enzyme loadings of both cellulases and P-glucosidase in order to achieve cellulose conversions greater than 70% due to the lower degradability of the softwood (Tengborg et al., 2001). Similar studies were carried out for saccharification of dilute-acid pretreated Douglas fir showing that enzyme dosage has a significant effect on glucose yield (Schell et al., 1999). Saha and Cotta (2006) obtained 96.7% yield of monomeric sugars using an enzy­matic cocktail of cellulase, P-glucosidase, and xylanase for saccharification of wheat straw pretreated by alkaline peroxide method. An ethanol concentration of 18.9 g/L and a yield of 0.46 g/g available sugars were achieved in the subsequent fermentation using a recombinant Escherichia coli strain capable of assimilat­ing both hexoses and pentoses. Jeffries and Schartman (1999) propose the use of sequential enzyme addition in a countercurrent mode for the saccharification of fiber fines from a paper recycling plant. Sequential addition of enzyme to the pulp in small aliquots produced a higher overall sugar yield per activity unit of enzyme than the addition of the same total amount of enzyme in a single dose. During the succeeding fermentation employing different yeasts, 78% ethanol yield of the theoretical maximum was obtained.