Simplification of the Biomass to Ethanol Conversion Process by Using the Whole Medium of Filamentous Fungi Cultivated Under Solid-State Fermentation

A novel simplified configuration is proposed for the conversion of biomass to ethanol using whole medium enzymatic cocktails (WM) and enzymatic extracts (EE) from different filamentous fungi (Trichoderma reesei, Aspergillus niger, and Aspergillus oryzae) cultivated under solid-state fermentation (SSF) for the hydrolysis of steam-exploded sugarcane bagasse (SESB). The hydrolyzed material derived from the saccharification of SESB using the combinations A. niger WM + T. reesei EE, A. oryzae WM + A. niger EE, and A. niger EE + T. reesei WM resulted in the best biomass conversion yields (66, 65, and 64 % of the theoretical reducing sugar yields, respectively). The best ethanol production (84 % of the theoretical yield) was obtained using the material hydrolyzed by a combination of A. oryzae WM + A. niger EE. The enzymatic conversion of SESB using on-site produced enzymes from the whole SSF cultivation medium, followed by an ethanol production step, is a potential configuration for the biomass to ethanol conversion process. This novel simplified configuration would enable the use of a single reactor system, avoiding the need for additional separation steps.