The Essentialness of Delignification on Enzymatic Hydrolysis of Sugar Cane Bagasse Cellulignin for Second Generation Ethanol Production

The enzymatic saccharification of partially delignified cellulignin (PDCL) of sugar cane bagasse was studied to verify how hydrolysis yield and hydrolysis rate were affected by the lignin content. Sodium hydroxide in concentrations ranging from 0.025-1 M (mol/L) was used to partially remove lignin. The remaining solids were subjected to enzymatic hydrolysis using commercial cellulases. The maximum glucose concentration was 40.4 g/L, corresponding to a cellulose conversion efficiency of 50 %; this concentration was achieved with 1 M NaOH. Subsequently, the enzymatic hydrolysis of alkaline non-pretreated samples was performed with different enzyme loads (25-150 FPU/g solids) to evaluate if an increase in enzyme load was necessary to reach the same glucose concentration when using PDCL. We found that all yields of enzymatic hydrolysis of non-pretreated cellulignin were lower when compared with alkaline pretreated samples because of the lignin content.